Monday, December 20, 2010

Is Logitech Z-623 the true successor of Logitech Z-2300?

Logitech Z-623


Logitech Z-2300


Even though Z-623 is touted by Logitech as the successor of Z-2300, I personally believe it does not packs the punch or have enough performance in it to be in the same league of Z-2300, let alone beat it. My beliefs were confirmed when my friend bought a Z-623, who also happens to owns a Z-2300. We did a full day audition of the Z-623 & compared it with the Z-2300 in every possible way, be it acoustic performance, quality of hardware used or just looks.

Note: I would recommend to read my post “Logitech Z-2300 : The Last of the Titans” prior to continuing with this comparison. A complete knowledge on Z-2300 will definitely help you to get a clearer picture about this comparison. 



The link to the my review of Z-2300 : Logitech Z-2300 : Mega Review


MARKET POSITIONING

Z-2300: When Logitech introduced Z-2300 way back in 2004, it was a THX certified premium quality top of the range product. The Logitech engineers in the lab where given a clear goal i.e. to create the ultimate 2.1 multimedia speaker system in the world. They were not concerned about the price, they were more concerned about the performance & quality of the system which lead in using premium quality components, be it electronic components, speakers used, wooden casings of the subwoofers, plastic casings of the satellites and even the wires used to connect the components. Price was never an issue, performance was. This single mindedness of the engineers produced a unique product, and Z-2300 was born.

If you consider that way back in the year 2000 when Logitech was known as a cheap speaker manufacturer and could not even meet the standards of Altec Lancing let alone Klipsch computer audio products, they made a huge effort back then in order to make a big step forward and used better quality components for their THX certified audio system lineup than they have ever done before thus increasing cost. My "Price was never an issue, performance was" statement is in context of my above view. Today when we compare the Z-2300 from an el chepo manufacturer Logitech with the HiFi maker company like Klipsch producing Promedia 2.1 as a computer multimedia speaker system, you find both of them being in the same segment going head to head in terms of audio performance and in many occasions Z-2300 coming out as a clear winner. Atleast we have to give credit to Logitech that that could produce a multimedia speaker system that can meet the standards of a Klipsch product. I give full marks to Logitech only for this effort.


Z-623: Logitech introduced Z-623 in 2010 six years after Z-2300 reign. Actually I cannot recall of a 2.1 PC speaker that remained at the top of the performance charts for straight six years. They had to make the successor not because Z-2300 was getting old and becoming incompetent, believe me it is still is the king, but because the rival manufactures like Altec Lansing, Edifier, Creative, Sony etc are producing cheaper sets which claim to have the same power & performance of Z-2300 while using cheaper materials and then labeling them as their premium products. Also 2.1 speakers sets are no more the cash cows of audio manufactures, rather these companies makes a lot of profit from selling the 5.1 & 7.1 speakers sets.

Thus, I believe this time the engineers were given a strict goal during the designing phase, i.e. to make a speaker set that beats its opposition like Altec Lansing MX-6021, Sony SRS DB-500, Edifier S530 or Creative Gigaworks T3 by a small margin. Z-623 was not designed to reach the same level of acoustical performance of Z-2300, let alone beat it. After all there is no need to provide Z-2300 levels of performance when Z-2300 itself will be discontinued.

Also from the marketing point of view Z-623 having the same performance level of Z-2300 was useless since any marketing division want a system that is better than their oppositions, so they can advertise that and get the propaganda.
Consider the case of these two 200W RMS 2.1 speaker sets.

Let us assume that Altec Lancing uses hardware worth $80 and have assembling cost of $10 per set of MX-6021 and sells it at $150. Profit = 150 – (80+10) = $60

Suppose in order to beat AL MX-6021, Logitech uses hardware worth $90 and have assembling cost of $10 per set of Z-623 and sells it at $150. Profit = 150 – (90+10) = $50

So, Logitech gives hardware worth $10 more thus having more performance than MX-6021 at the same price in order to garner more sells at that price range.

Now, if Z-623 was supposed to beat Z-2300, then Logitech would have to use hardware worth $120 and have assembling cost of $10 per set of Z-623 and sells it at $150. Profit = 150 – (120+10) = $20

So, Logitech’s profit margin would have fallen from $50 to just $20 per set. And since Z-2300 will be discontinued & the current speaker sets having way below performance level than that of Z-2300, $50 profit per set was found more of a sensible option and correct from the logical point of view. If I was at the helm of Logitech I would have done that too. Unfortunately for customers, what they get is a good product but not an excellent one like Z-2300.

SPECIFICATIONS

Z-2300
Audio Quality Certification: THX certified
Total RMS Power: 200W [FTC rated power]
Total Continuous Power: 120W [Estimated]
System THD: Better than 0.05% before clipping 
Total Peak Power: 400W
Power distribution: 120 W (Subwoofer) + 2 X 40 W (Satellites)
Subwoofer: 120 W @ 8 ohms
Subwoofer Size (inch): 8
Satellites: 80 W (2 X 40 W) @ 8 ohms
Satellite Size (inch): 2.5
Frequency response: 35 Hz - 20 kHz
Signal to noise ratio(SNR): @ 1kHz > 100dB
Sound Pressure Level (SPL): 117db
Subwoofer dimensions(HWD): 11" X 11" X 15"
Satellite dimensions(HWD): 6.75" X 3.5" X 6"
Total weight : 15 Kg

Z-623
Audio Quality Certification: THX certified
Total Power: 200W <-- Is it FTC rated power? No Mention. Why?
System THD: No Mention. Why?
Total Peak Power: ????
Power distribution: 130 W (Subwoofer) + 2 X 35 W (Satellites)
Subwoofer: 130 W @ 8 ohms
Subwoofer Size (inch): 7
Satellites: 70 W (2 X 35 W) @ 6 ohms
Satellite Size (inch): 2.5
Frequency response: No Mention. Why?
Signal to noise ratio(SNR): No Mention. Why?
Sound Pressure Level (SPL): No Mention. Why?
Subwoofer dimensions(HWD): 12" X 11" X 10"
Satellite dimensions(HWD): Unknown
Total weight : 10 Kg [5 kg lighter than Z-2300]

DELIBERATE MEASURES TO HIDE PERFORMANCE DEFICIENCIES OF Z-623 IN RESPECT TO Z-2300

Frequency Response: Frequency response is the measure of any system's output spectrum response to an input signal. Humans are able to hear any sound between 20Hz to 20kHz. Any multimedia speaker system that can cover this entire range is regarded as a great achievement for the manufacturer so that the user can hear each &every note of the music playing.

While it is quite easy to go up to 20kHz to produce high frequency (treble), a manufacturer have to spend a lot of money in the hardware department in order to go way down in the frequency spectrum and reach 20 Hz (Bass). To produce frequencies at 20 Hz you need a bass driver which is at least 12 inch or more in diameter and also have lots of power from the amplifier to power that driver in order to move huge volumes of air.

Since Z-2300 uses a 8 inch bass driver it can go as low as 35Hz and its frequency response is in between 35Hz–20kHz which is quite a respectable figure. For Z-623 there is no mention of frequency response of the set in their website. Why? Is it because Z-623 7 inch bass driver being an inch shorter than Z-2300 was not able to go as low as 35Hz as in Z-2300 could have and hover around 45-50Hz? I think so.

System THD: The total harmonic distortion (THD) is there to give us a measure of how much the audio signal is distorted when playing the system. Z-2300 had better than 0.05% THD before clipping which was excellent from acoustical performance point of view. In Z-623 there is no mention of these criteria in their website. Why? Is it because Z-623 THD is nowhere near that of Z-2300? I think so.

SNR: Signal-to-noise ratio (SNR) is a measure used in science and engineering to quantify how much a signal has been corrupted by noise. It is defined as the ratio of signal power to the noise power corrupting the signal. Z-2300 had hifi level 100dB SNR which was way better than 70-80 dB SNR its opposition was able to manage. For example, Altec Lansing MX-6021 have only 75db SNR. For Z-623 there is no mention of these criteria in their website. Why? Is it because Z-623 SNR also hovers at around 75dB and thus nowhere near that of Z-2300? I think so.

FTC rated power: FTC as a governing body provides strict rules for output power claim. According to their rule, wattages stated are the sine wave continuous average power output measured using US FTC Title 16 Part 432 (RMS) rating, not “peak” or maximum power output. For Z-2300 Logitech clearly stated 200W of FTC Rated Power & 400W RMS of peak power. For Z-623 Logitech just states 200 W RMS of power. Why? Is it because Z-623 was not able to match the power output of Z-2300? I think so.

Weight: For multimedia speaker systems, weight is an indicator of good, robust design because it suggests that the speakers are made of thick MDF, have big drivers (speakers) with large magnets in them to handle lots of power from the amplifier, and therefore have plenty of capacity. Also weight is an good indicator for the internal amplifier because it suggests that the amplifier’s important internal components--the power transformer, heat sinks, and storage capacitors -- are large, and therefore have plenty of capacity to process and store large amounts of power to handle loud dynamic peaks without distortion.

Z-623 is 5 kilograms lighter than Z-2300. I mean you can buy a moderately good 2.1 speaker system which weighs 5 kg. It also much smaller than Z-2300 and a space saver too, but if you look purely from an acoustical performance point of view of any sound systems generally the bigger & heavier becomes the winner. Why? Let me describe …

SUBWOOFER COMPARISON

Z-2300: The subwoofer is huge, in every sense of the word. The behemoth measures 11” (H) X 11” (W) X 15” (D), and its output could both rattle the paint off your walls & take the wind out of your lungs at the same time. The enclosure is very deep, which is great from an acoustical performance viewpoint. The subwoofer weighs 12 kilograms and is a back breaker for sure.

Actually, this subwoofer was designed for Z-560 way back in the year 2000. Z-560 was the first THX certified multimedia speaker system from Logitech and was a big gamble at that time. Nobody was quite sure how the market will react in accepting a high end computer speaker from this unknown brand. But it seems that the gamble finally paid off and ever since this Holy Grail subwoofer have been used in their THX certified speaker systems line up for the past decade as below:
Z-560 [first THX certified 4.1 system, launched in the year 2000]
Z-680 [first THX certified 5.1 system, launched in the year 2002]
Z-2200 [first THX certified 2.1 system, launched in the year 2003]
Z-2300 [second THX certified 2.1 system, with minor updations on Z-2200 launched in the year 2004]

There is a department in Logitech that exclusively deals with audio products and are better known as Logitech Sound Central. The link to the website is provided here:Logitech Sound Central

They state: “We don’t simply buy parts off the shelf. We laser tune different types of drivers. We modify the shapes, experiment with materials, and use digital components to improve sound quality. Our goal is to deliver fidelity as close to the original sound as possible.

Logitech Sound Central testing the bass driver of Z-5500


The subwoofer also houses a patented “U” shaped exponentially increasing bass reflex port to produce distortion free deep and rich bass experience. The enclosure is very deep, which is obviously good from an acoustical standpoint.

Z623: The Z623’s subwoofer is two thirds the size of Z-2300. It measures 12” (H) X 11” (W) X 10.5” (D). Logitech kept the height & width almost identical but the depth of the box was drastically reduced by near 5 inches. From performance aspect this can never be considered a positive, since at least for subwoofers the simple theory of “The Bigger the Better” hold absolutely true.

From a technical point of view, Z-623 does not need a subwoofer enclosure as big as Z-2300 since the bass driver is an inch smaller in diameter measuring 7 inches and thus requiring a lot less volume of air inside the enclosure. But in return, Z-623 subwoofer will be much less powerful as compared to Z-2300. I think the 7 inch bass driver have a rated input power of 50W RMS if you consider the 8 inch bass driver of Z-2300 was rated 80W RMS.

What I found amusing is that Logitech states this 7 inch bass driver can is capable to handle 130W RMS of power from the amplifier when the 8 inch bass driver of Z-2300 was always on overdrive mode handling its 120W RMS. This is the biggest proof that there is something fishy about the stated power of Z-623 & the amount of bass produced by the subwoofer or its loudness have substantially reduced by a good margin.

Also, the Z-623 subwoofer is nearly 4 kilograms lighter than Z-2300 sub. Where does this 4 Kilos go? Just vanished? Or is this is due to a smaller bass driver with a smaller magnet being enclosed in a smaller subwoofer enclosure with a thinner wall thickness than that of Z-2300?

SATELLITE COMPARISON

Z-2300 uses 2.5 inch polished aluminum phase plug drivers in their satellites and are beautifully crafted to look like a piece of art. The 12W satellite drivers that Z-2300 uses are again from an unknown speaker company and does not in any way relate to 3 inch Tang Band (W3-594SB) units. I estimate a rated power of 10W & a max of 20W. But since these drivers get audio frequencies ranging from 150Hz to 20kHz, the power handling capability increases by at least two times. So these speakers can handle anything between 20W to 40W.

Z-623 uses the same 2.5 inch polished aluminum phase plug drivers in their satellites. Z-623’s satellites are complete black units and are plain ugly, where as Z-2300’s satellites with silver & black tones are beautifully crafted and looks like a piece of art.

AMPLIFIER COMPARISON

Both Z-2300 & Z-623 houses the amplifier in their subwoofer assembly.

Z-2300:

Power Supply

The power supply of an audio amplifier is of vital importance, since it provides all the juice required by power amplifiers to drive the big speakers. An underperforming power supply will seriously limit the performance of an amplifier.

The power supply consist of:

i) A center tapped toroidal transformer manufactured by Ten Pao International. This transformer is rated at 150.9VA with +/- 20.1VAC secondary, 3.75A.

ii) A metal cased bridged rectifier to provide full-wave rectification from +/- 20.1 VAC to DC.

iii) A pair of CapXon 10,000 uF, 35V capacitors one for + 20.1 VDC and the another for – 20.1 VDC acting as ripple filters in order to smooth the DC output.

A toroidal transformer uses a doughnut shaped core & is much slimmer than a conventional (EI) transformer. It has numerous advantages over EI type such as low weight, low hum, low noise and also being smaller in size than an equivalent EI type. On the downside they are much more expensive than a conventional EI transformer. But it is worth the pay since you get better performance. A toroidal transformer has so many other performance advantages over EI type that it is hard to describe here other than to provide the performance ratio. Toroidal : Conventional(EI) :: 158 : 5 . It you want to know more in details go to the link below:
Bryston Transformers

The transformer used here is rated to have an output of two times 20.1VAC when it has its rated load. So its resistance has already dropped the open circuit voltage and its peak will be 1.414 times higher which happens to be 28.4VAC. A single rectifier here drops it by 1VDC to 27.4VDC and smoothing the ripple by the power capacitors drops it by another 1VDC to 26.4VDC.

So, DC voltage supplied by the power supply is +/- 26.4 VDC, the current being 3.75 A. 

Amplifier Chips

Z-2300 uses Class-AB power amplifiers from STMicrolectronics. STMicrolectronic is a very renowned name in audio amplifier market.

The amplifiers used are:

i) A Japan Radio Corporation’s JRC-4565 operational amplifier. JRC-4565 is a dual op-amp which means it has two op-amps inside it to handle stereo channels.

ii) Two voltage regulators a 78M18 and a 79M18 supplying +/- 18 VDC respectively to feed JRC-4565 op-amp from the +/- 26.4 VDC power rail.

iii) Four STMicroelectronics, Class-AB, 60W, TDA7296 power amplifiers. Two of these are used to power each satellites while the other two are bridged together powering the subwoofer.

Z623: I am unable to give you a clear detail of the Z-623 amplifier, since my friend was reluctant to open the newly purchased set, which is quite understandable. But minutely looking at the subwoofer, I found out that there is no slow blow fuse.

Also surfing the net I found out Logitech have completely replaced the Z-2300’s 200W [FTC Power Rated] Class-AB amplifier module powered with expensive toroidal transformer with cheapish Class-D amplifiers powered by switch mode power supplies (SMPS) as found inside our computers. The trend to Class-D was first started by Logitech in Z-Cinema which was a hybrid Class-AB/ Class-D.

TRUE CONTINIOUS POWER OUTPUT FIGURES 

Z-2300 amplifier’s continuous power output capability 

Remember that Z-2300 produces 200W of FTC Rated Power. But this is by no means continuous power. In order to produce 200W of continuous power, an amplifier will need a transformer that is capable of to deliver a minimum of 1.27 times the claimed wattage. Since Watt is volts multiplied by ampere, 200W of output requires 254 watts or 254VA transformer as a minimum requirement.

So, Z-2300’s supplied 150.9VA will produce a maximum of: (200/254) X 150.9 = 119W =~ 120W of continuous power @ 0.5% THD @ 8 ohms @ 26.4 VDC

Since the ratio of power distribution between the subwoofer and the satellites is in the order of 3:2, the subwoofer is capable to produce 72W of continuous power while each satellite gets 24W of continuous power.

This becomes even more evident from the fact that the bass driver has a rated input power 80W, while the satellite speakers can handle anything between 20 to 40 watts.

Z-623 amplifier’s continuous power output capability 

Considering the case of Logitech Z-Cinema claimed 180W, I dismantled it myself and found out
1) One Philips TDA8920 100 watts Class D amplifier for the subwoofer.
2) One Philips TDA8922 50 watts Class D amplifier supplying 25W to each of the midrange speakers of the two satellites.
3) One STMicroelectronics TDA7269 20 watts Class AB amplifier supplying 10W to each of the tweeters of the two satellites.

Total maximum amplifier chip power of Z-Cinema is 100 + 50 + 20 = 170W, where as
Total maximum amplifier chip power of Z-2300 is 4 X 60 = 240W

Logitech Z-Cinema


Now look at the Z-Cinema's switching power supply powering the amplifier as below:



Take at even closer look at the main component of the Z-Cinema's switching power supply :



It is clearly stated, MAX TOTAL OUTPUT POWER 83.3W

So, Z-Cinema’s supplied 83.3W will produce a maximum of: (83.3/1.11) = 75W of continuous power.

Since the 75W continuous power of Z-Cinema is said to produce 180W by Logitech, I believe the Z-623 maybe have at around 80W continuous power and is down by 40W to the 120W continuous power of Z-2300. Also the switching power supplies of Z-623 can never go beyond their rated power[93.3W estimated]. Where as the Z-2300 with its toroidal transformer & filter capacitors can easily produce 200W for a short period of time.

Discrepancies about Power Output Figures 

Remember that most audio amplifiers do not have power supplies capable of driving their rated power continuously. This holds absolutely true for all computer multimedia speakers systems & consumer home audio products. Only HiFi systems costing a lot of money have power supplies that can match the continuous power rating of the amplifiers.

This is because music is not like a continuous sine wave. It has peaks of intensity, then relatively quiet periods. If music has a 20dB dynamic range then if the peaks are 200W, the average power is probably around 5W.

A transformer can sometimes go well beyond its rated power output for small amount of time to handle these peaks of intensity. For example the 150.9VA transformer of Z-2300 can go up to 180VA to handle the peaks & produce 140W power for that moment.

If even further power is required to handle this peaks of intensity, say 200W, then the additional 60W is supplied by the two large 10,000uF, 35V power supply filter capacitors of Z-2300 for this short period of time. The filter capacitors can charge back up during the relatively quiet periods.

So the 150.9 VA transformer of Z-2300 is perfectly capable to deliver 120W of continuous power & can easily handle peaks reaching 200W. Remember that the Z-623’s switching power supply is not able to attain this feat and stays at 93.3W. I think that is the reason why Logitech have not quoted peak power output of Z-623

Also Logitech states that Z-2300 have a Total RMS Power of 200W. Look at the absence of the “continuous” word. Except HiFi systems, you will always find these consumer audio companies talking about “Total RMS Power”, “FTC Rated Power”,“Power”, “Total Peak Power”, “System Power”, “Music Power”, “Peak Music Power Output (PMPO)”,…………….. and the list goes on. But you will never find them talking about “Continuous Power” which happens to be the actual power of the amplifier.

Reasons for using Class-AB Power Amplifiers

A quick look at many new low power speaker amplifiers on the market highlights the move to Class-D audio performance, but when it comes to low distortion and low noise and best sound quality, Class-AB still has the edge.

Class-AB architecture offers a signal to noise plus distortion ratio of up to 10 times better than its equivalent Class-D neighbour as well as providing a much simpler architecture which can be tweaked as required, without the need for reactive filter components on the output and the electromagnetic radiation resulting from an output stage switching at a few hundred kHz. Class-D amplification has inherent distortion in it and therefore is predominantly used in lower bandwidth amplification like in subwoofers. In other words it is quite impossible for a Class-D to achieve the level of linearity in frequency response produced by a Class-AB amplifier.

Ultimately it comes down to what you want, for efficiency and cost effectiveness Class-D are best, but if you are ready to sacrifice some efficiency & increase cost for the sake of sound quality then Class-AB are the best. In other words Class-A amps sound the best, cost the most, and are the least practical. They waste power and return very clean signals. Class-AB amps dominate the market and rival the best Class-A amps in sound quality. They use less power than Class-A, and can be cheaper, smaller, cooler, and lighter. Class-D amps are even smaller than Class-AB amps and more efficient, because they use high-speed switching rather than linear control.

The most important reason behind which multimedia speaker manufactures are switching from Class-AB to Class-D is to increase profit margin. Class-D is very cheap to produce and does not need require a big extruded aluminum heat sink or expensive toroidal transformers. They are basically switching power supplies but utilize pulse width modulation so as to be able to reproduce and amplify an alternating current. There are ok for subwoofers, but I honestly think that it is ridiculous to use a Class-D amplifier in a high end studio monitor.

In short, Class-D amps are more efficient but are only good for low frequencies applications like subwoofer amplification. Class-AB amps can be used full range amplification i.e from 20Hz – 20kHz. Class-D amps cannot be used on highs frequency response because they only produce square waves because of the technology involved, so they will make your highs sound lifeless and tinny. Class-AB amplifiers produce full variable signals and can capture subtle nuances better, sound warmer and generally have more depth in their sound.

CONTROLS

Z-2300: The control pod of the Z-2300 is quite simple, minimalistic & functional, which I prefer. No fancy lights just a big volume knob, a bass control, a 3.5 mm headphone jack, power LED and a power button. You can keep the control pod on your desk where ever you like and the controls are very convenient.

Z623: The volume knob, bass control, 3.5 mm headphone jack, power LED and power button are all integrated on the right satellite. Now every time you need to make an adjustment you have to reach your hand out to the right satellite. This becomes very irritating and once again reminds me that it is a deliberate move by Logitech to cut cost.

DRASTIC MEASURES TAKEN TO CUT COST

Logitech have gone a whole way to reduce cost of the hardware in Z-623 in comparison to Z-2300.
1) The subwoofer is smaller & lighter with thinner wall thickness and no silver/black design. Saves cost.
2) The bass driver is smaller by an inch & have smaller magnet. Saves cost.
3) Jump from Class-AB amplifiers to Class-D with much less power. Saves cost.
4) Switching power supply instead of toroidal transformer. Saves cost.
5) No heat sink at the back of the subwoofer. Saves cost.
6) No master power switch & external fuse on the subwoofer. Saves cost.
7) Much thinner & shorter wires. Saves cost.
8) Satellites are ugly and use black plastic instead of glossy silver/black design with mesh cover of Z-2300 satellites. Saves cost.
9) Integrated controls with right satellite instead of separate control pod. Saves cost.

REPAIRING

No doubt that Logitech produces speaker system with excellent built quality that are built to last for decades. But at least for electronic components like speaker sets nothing is for sure. And also remember that Logitech will provide support for the initial 2 years, after that there will be no support. So what happens when:

1) Bass driver blows: Since Z-2300 uses an industry standard 8 inch bass driver, you can find a hundred speaker companies out there to provide a 8 inch bass driver that fits into the Z-2300 subwoofer assembly. Check YouTube & you will find a hundred examples out there.

Since Z-623 uses manufacture specific & odd sized 7 inch bass driver, forget about getting it replaced with a new one. So, you end up with a dead system.

2) Amplifier Module: Class-AB amplifier modules found in Z-2300 are very easy to repair, any local repairing shop will do that for you, and the amplifier chips and components are readily available in the market for replacement. Same goes for Z-2300 toroidal transformer.

Z-623 uses Class-D amplifiers & switching power supplies which are piles of crap after they are broken or dead. Just think when your PC’s power supply (SMPS) blows out you do not repair them since they require costly machinery for repairment & also the parts are not readily available. So you just buy another SMPS and fit into your PC.

The problem with Z-623 is it does not use a industry standard SMPS as your PC but are manufacture specific, which the manufacturer (Logitech) will not provide to you after 2 years. So, you end up with a dead system.

3) Satellites stop working: Z-2300 uses two satellites that are connected to the subwoofer with industry standard RCA input cables. Suppose one of them stops working, I can buy a dozen pair of bookshelf speakers having RCA input cables available in the market and directly plug to the Z-2300. All I have check is that each bookshelf can handle at least 40W RMS of power & are rated at 8 ohms.

As for Z-623 you can do that for the left satellite as it comes with RCA cabling but not the right one which comes with manufacture specific D-Sub plug. Also, the satellite speaker impedance rating is 6 ohms which is kind of odd, since 4 & 8 ohms are readily available in the market. So, if the right satellite goes you end up with a dead set.

PERFORMANCE

Z-623 performs admirably well in movies & games. It also performs well in music. It may not have the same hardware architecture of Z-2300, but Logitech engineers have made sure that Z-623 possesses the genes of Z-2300. It definitely has the upper hand over its opponents namely Altec Lansing MX-6021, Sony SRS DB-500, Edifier S530 & Creative Gigaworks T3 in terms of performance. No doubt Z-623 is the winner among the current heard and also the best of the lot in terms of performance/ price ratio.

But when you put the Z-2300 in the above equation, everything falls loose. Z-2300 is like a lion among a herd of cattle’s named Z-623, DB-500, S530 & T3.

1) None of the above sets have the power output capability of Z-2300. Z-2300 is the loudest of the lot and makes the opposition eat the dust.

2) Z-2300 has wonderful power reserve in the amplifier & thus do not distort even at full volume. Z-623 & all the other sets distorts at full volume.

3) In terms of music representation Z-2300 is second to none. Since Z-2300 uses Class-AB amplifiers, the sound produced by Z-2300 is more natural, very well defined & represents the true analog nature of the human voice. Both male & female voices are excellently represented in Z-2300. In contrast Z-623’s Class-D amplifier lacks a little bit of the natural feel & warmth in the sound as found in Z-2300 and represents more that of MX-6021 & DB-500 in their sound characteristics. The subwoofer has tight bass but the overall bass of the Z-623 is not well defined. A system with Class-AB amplifiers (as in Z-2300) will produce bass which is a little less deeper than a Class-D of Z-623, but the bass will be much more defined & accurate and also feel more natural & real.

For example, playing the track "Chant" of the band Foreplay, I noticed that the kick drums of that track produce "boom boom boom" on the Z-623. Playing the same track on Z-2300, the kick drums sounded "booouuumm booouuumm booouuumm" which happens to be the actual sound of kick drums. In contrast, Z-623 bass goes a little deeper but is less natural & neutral. Audiophiles will definitely choose Z-2300 over Z-623 for these single criteria.

4) In movies & games which do not contain the subtle nuisances of complicated music reproduction, Z-623 is right up there with Z-2300. If you just want a speaker set for movies & games you will be blown out with the performance levels these Z-623 babies can achieve.

VERDICT

Z-2300 is hitting the end of the production cycle. It is the last of the titans which is finally going to take slumber. But it is going to rule the hearts of those who were lucky enough to possessed them and experience their performance. If you really need a high end 2.1 THX certified multimedia speaker system don’t waste any more time and get a Z-2300 while it is still available. If it not available then only greet the new champ of the block, Logitech Z-623.

Sunday, December 19, 2010

Review of Creative Gigaworks T3 & comparative analysis with Logitech Z-2300

Most of you may be aware of the Gigaworks line up of speakers from Creative.
Recently, I checked out the Gigaworks T3.

Specs

Logitech Z-2300 ($115)


Total Continuous Power(RMS): 200 W
Satellites(RMS): 80 W (40 W x 2) @8 ohm
Subwoofer(RMS): 120 W @8 ohm
Frequency response: 35 Hz–20 kHz
Signal-to-noise ratio(SNR): >100 dB
Satellite Drivers: 2.5-inch polished aluminum phase plug driver
Subwoofer Driver: 8-inch long-throw driver

Creative Gigaworks T3 ($240)


Total Continuous Power(RMS): 80 W
Satellites(RMS): 30 W (15 W x 2) @8 ohm
Subwoofer(RMS): 50 W @4 ohm
Response Bandwidth 30–20 kHz
Signal-to-noise ratio(SNR): >90dB
Satellite Driver: 2 inch, metal diaphragm driver
Subwoofer Driver: 1 x active subwoofer driver 6.5 inch + 2 X passive 6.5 inch

Design & Build

Gigaworks are known for their compact speaker systems. The T3 is a 2.1 Gigaworkssystem and gets the same treatment.

Satellite


The satellites houses two tiny drivers, much smaller than Z-2300 satellites and have a cube-like design, perched on slim stands. The cube houses inch full range driver. They are not phase plug driver type as found on Z-2300 but are of metal diaphragm type. The driver is hidden behind a fabric mesh to prevent dust collection. But they seem better without them on, more like the aggressive performance system that Gigaworks is meant to deliver.

The stand on which these drivers sit isn't the adjustable kind.The stands have good rubber feet for a firm grip. Thought the speakers are small and compact the attached metal stand makes it quite heavy.

Now coming to the subwoofer of the T3, which is the main and most unique component of the system. It is a three-way firing subwoofer, so we get three 6.5 inch drivers. But all three are not active drivers. The passive drivers take up the two sides while the front one only being active. There is no bass reflex port which means the subwoofer is airtight. It is a good means to produce bass that has a deeper feeling, but that comes at the expense of loudness of the subwoofer.

At the rear of the subwoofer are the connectors for both left and right speakers. This includes the volume control and the connectors for the control pod/wired remote. Theaudio input RCA type and the bass level of the acoustic module are also present here. The bass can be set to a neutral level or increased and decreased. The placement of the bass level knob at the rear is really not the best idea and it would have been better placed in the control pod, like the Z-2300.

I found control pod of the T3 is a very simple unit. It is wired and with no wireless remote provided. I feel that the whole "premiumness" of the T3 is more or less lost here. The Control Pod looks neat with the use of chrome rings present on it. The wire is long enough to reach up to most desks. There is a headphone jack and a line-In or AUX jackpresent on it as well making it simple to connect MP3 players or other external sources. In between these two jacks there is a purple LED which lights up stating that its drawing power or the speakers are powered. The LED stops glowing when the speakers are not being used thus sending the T3 into standby. The pod has a neat rubber base to hold onto most surfaces it's placed on.

Features

Gigaworks has always packed something special in all its speakers, and the T3 is no different. While we have seen almost every Gigaworks speaker feature BassXPort, the T3 has a new technology for providing better sound - SLAM. Let's now take a closer look at this new feature.

SLAM is the acronym to 'Symmetrically Loaded Acoustic Module'. This technology, just like BassXPort, is meant to provide better bass. The difference between the two is that BassXPort is meant for standalone speakers that don't have a subwoofer or woofer. SLAM on the other hand is a more enhanced subwoofer. It incorporates one active and two passive drivers into a single subwoofer in the quest to produce over double the bass from a single subwoofer, instead of using two subwoofers. This turns it into a three-way firing subwoofer. The front facing subwoofer is the master driver, while the other two help in creating a pressure barrier to contain the low frequency, so that the thump is deeper in feeling.

Drivers

Satellite Driver


I found that the drivers are quite small at just 2 inches and also the satellite box that holds the driver being small to. The problem with this is, though small full range drivers in small boxes deliver excellent high frequency response, what they will definitely lack is midrange, simply because you need bigger diaphragm (more than 2 inches) & much larger air volume inside the satellite box to produce a decent midrange.

Since T3 uses metal diaphragm drivers which are fast and light, and have very high resolving power, they obviously provide incredible detailed high-frequency response in expense of midrange. This kind of "crispy boom" sound, is a rave among young people who think it as the clarity of the system. But for more experienced audio people, it is not the accurate or real sound.

The Z-2300 on the other hand have drivers that are 2.5 inches (3 inches would have been even better) and they are fitted in a satellite box that is twice the size of T3. So from a technical point Z-2300 satellites will have better midrange. My personal view is that the satellites of the Z-2300 produce the most accurate sound of any 2.1 multimedia speaker system available today within its price range. Remember i said "accurate" which means just as the sound was meant to be heard, not the more clear "crispy boom" type with perceived clarity.

I seems T3 have gone the BOSE way.

Subwoofer


The bass driver is 6.5 inches and are just okay for me. Actually any person with decent knowledge about sound systems will consider drivers of 8 inches & more in size as real bass drivers that are suitable for subwoofers. Z-2300 uses a 8 inch bass driver, so for me Z-2300's has a real subwoofer.

The theory is that in order to produce low frequencies of the sound spectrum, you need prodigious power (watts of power) in order to move huge volumes of air. To do so you need a driver with big diaphragm (thus 8 inches or more in size) and lots of watts from the amplifier powering the driver. Also the size of the subwoofer also counts, since the bigger the bass driver size the bigger the subwoofer assembly gets and thus can produce more defined, more powerful & more accurate bass than a smaller subwoofer.

Z-2300 subwoofer is twice the size of T3's. No question, Z-2300 wins in the subwoofer department hands down.

Amplifier module of T3



The amplifier unit is at the back of the subwoofer. The quality of craftsmanship, the PCB layout of the amplifier is top notch & the best i have seen among multimedia speakers. It is even better than Z-2300. But this praise goes for craftsmanship & design, not for the components used in the amplifier assembly.

The thing that spoils this party is the rather lame EI type power transformer that is used to power the amplifier. If you look at the picture showing the subwoofer internals as above you will find that the EI type transformer is sitting in the middle. At $240 I expected at least a toroidal transformer as found in Z-2300. The toroid is way superior than any EI type, but generally cost 50% more than a similar EI one.

The biggest disappointment for me is that T3 uses a rather chepo Class-D Texas Instruments TAS5142 power amplifier. I personally believe a Class-AB amplifier would have produced far superior sound. But that would have increased their cost of building this system & a dent in profit margin.

On the other hand, I am quite pleased to find that Z-2300 uses four Class-AB power amplifiers. Also doing a gross oversimplification of the price of the components as found on the amplifier modules of both T3 & Z-2300, Z-2300's amp module cost nearly two times that of T3's.

TAS5142 is a 2 × 100 W digital amplifier chip, to achieve output of 100W per channel, need to BTL (bridge) mode. In fact, it is a 4-channel amplifier chip, 4 ohms impedance, to achieve 4 × 30 W output. The chip, being Class-D have high efficiency, over 90%, that is, most energy is converted into sound, only 10% of the electrical energy is converted into heat energy.

Texas Instruments TAS5142 [Stereo Digital Amplifier 2 X 100 W]


REASON FOR USING CLASS-AB AMPLIFIERS

A quick look at many new low power speaker amplifiers on the market highlights the move to class D audio performance, but when it comes to low distortion and low noise and best sound quality, class AB still has the edge.

Class AB architecture offers a signal to noise plus distortion ratio of up to 10 times better than its equivalent Class D neighbour as well as providing a much simpler architecture which can be tweaked as required, without the need for reactive filter components on the output and the electromagnetic radiation resulting from an output stage switching at a few hundred kHz.

Class D amplification has inherent distortion in it and therefore is predominantly used in lower bandwidth amplification like in subwoofers. In other words it is quite impossible for a Class D to achieve the level of linearity in frequency response produced by a Class AB amplifier. Class D achieves about 90% power efficiency compared to about 60% respectively for Class AB.

Ultimately it comes down to what you want, for efficiency and cost effectiveness Class D is best, but if you can sacrifice some efficiency & increase cost for the sake of sound quality then Class AB is the best.

In other words Class A amps sound the best, cost the most, and are the least practical. They waste power and return very clean signals. Class AB amps dominate the market and rival the best Class A amps in sound quality. They use less power than Class A, and can be cheaper, smaller, cooler, and lighter. Class D amps are even smaller than Class AB amps and more efficient, because they use high-speed switching rather than linear control.

The most important reason behind which multimedia speaker manufactures are switching from Class AB to Class D is to increase profit margin for the company. Class D is very cheap to produce and does not need require a big extruded aluminum heat sink or expensive toroidal transformers. They are basically switching power supplies but utilize pulse width modulation so as to be able to reproduce and amplify an alternating current. There ok for subwoofers, but I honestly think that it is ridiculous to use a class D amplifier in a high end studio monitor.

In short, Class D amps are more efficient but are only good for low frequencies applications like subwoofer amplification. Class AB amps are generally 30% less efficient but can be used full range amplification i.e from 20Hz – 20kHz.

Class D amps cannot be used on highs frequency response because of the way they work. They only produce square waves because of the technology involved, so they will make your highs sound lifeless and tinny. Class AB amplifiers produce full variable signals and can capture subtle nuances better and sound more warm and generally have more depth in sound.

Since T3 uses Class-D amplifies which emit little or no heat, it has a tiny heat sink as shown below:



Performance

Pushing it through the music, movies & game tests the T3 performed quite well. The highs from the satellites are sharp and there was no distortion even at max volume. The mids are present and but are not quite defined as predicted, though the satellites seems to get a bit too sharp at higher volumes. The mids die out as it gets a bit overshadowed by the characteristic shrilly highs of the Creative speakers. They are present but you can make out the difference.

The T3 is crystal clear up to 60% of the volume but after that point it goes off balance and the shrill from the satellites take over. On the other hand the Z-2300 remains superbly composed even at full volumes. The T3 system overall is balanced but you need to keep the volume between 10-60% (under 10% it's soft and over 60% it fades a bit with increase in volume).

Note that the upper midrange is a bit overdone, which may be a little flattering and the extreme treble is little bit attenuated to provide the "crispy boom" effect. That is the reason why women voices performed better than male voices, since for male voices needs better midrange.

The Z-2300 satellites are more powerful at 80W RMS (instead of 30W RMS of T3) and produce a far superior natural, soothing & smooth sound with clear detailing on every note which is so pleasant to hear. Both male & female voices are excellently represented on the Z-2300.

The 50W RMS subwoofer of T3 was able to deliver quite a thump. I dare say that I am seriously impressed with this thump. It's a unique thump though it still needed tuning.The subwoofer has tight bass but the overall bass of the T3 is is not well defined. This is a normal "techno" bass character of Class-D amplifiers. A similar Class-AB amplifier(as in Z-2300) will produce bass which is a little less deeper than a Class-D, but the bass will be much more defined & accurate and also feel more natural & real.

For example, playing the track "Chant" of the band Foreplay, i noticed that the kick drums of that track produce "boom boom boom" on the T3. Playing the same track on Z-2300, the kick drums sounded "booouuumm booouuumm booouuumm" which is the actual sound of kick drums.

Z-2300 successor Z-623 also sound "boom boom boom" as it uses Class-D amplifiers. More of it in the next post.

Since the satellites are very small and uses very small full range drivers, they affect the overall bass produced by giving it a rough edge. It can't be noticed at lower volumes but is noticeable as soon as you turn up the volume even with the subwoofer set to neutral. With the bass pumped to a higher level the roughness in the bass gets more profound. On reducing the bass level and going below neutral, the bass seems poor. Overall SLAM has potential and can deliver but it needs to get better. But, all said and done the bass of T3 is good for the size of the subwoofer.

Comparing it with the benchmark 120W RMS subwoofer of the Z-2300, I was amazed that it completely matched the Z-2300 up to 50% of Z-2300’s volume and produced the same slamming & chest thumping response Z-2300 is so famous for. But after that it was as always Z-2300’s territory. I am very impressed with the T3’s bass i would have loved the use of more expensive Class-AB amplifiers.

The performance of the T3 isn't all it's cracked up to be, with good 2.1 systems like Logitech Z-2300 around. It has a slight edge but only at certain volumes, but still loses out on the whole. Its small & compact size is the main factor that limits its performance.

GRAPH


As you see above, T3 is nicely balanced & provides a wide response through out the frequency range. It is important to note that T3 is way superior than Altec Lansing MX-6021 in terms of balanced frequency response.

Verdict

The Creative Gigaworks T3 costs a whopping $240 with a one-year warranty. In comparison Logitech Z-2300 is available at $115.

Buying the T3 is like paying double the price of Z-2300 to buy half of its performance. This is a ultra steep price just like any other product from the Gigaworks line up. At this price you'd expect something like near studio quality, which sadly is not the case. Actually if Audio Engine have made a bookshelf between A2 & A5 say the A3, T3 would have made circles around A3 all day long.

I have the Altec Lansing MX-5021 and the Z-2300 from Logitech. Both of them are THX certified. The Z-2300 being the better of the two, and a much better buy over theGigaworks T3 in the price to performance ratio.

Ask me and I'll repeatedly choose the Z-2300 for the performance it offers at that price. It actually provide much superior performance than T3 at half of its price. As for theGigaworks T3 all I have to say is that the SLAM technology still has to prove its mettle. I won't pay the premium for a technology that can, as of now, only deliver a 0% better performance over a system(Z-2300) that costs less than half of its price.

Please, stop coping my threads/ posts!!!!!!!!

Currently, I am finding out a lot of people are just coping my thread/ post contents and touting as they have wrote it themselves. While on one hand it is making be proud that my views are worth coping, on the other I am getting a little big upset that the copiers are not give me the credit. 


Any how to prove that I am the Real One I provide links below of various threads of various forums where I provided the reviews under RishiGuru/ rishiguru/ rishiGuru name.

AVSForum.com
Logitech Forums
HiFiVision.com
ThinkDigitForums.com

Logitech Z-2300 : Mega Review




INTRODUCTION

Logitech Z-2300 
When Logitech introduced the Z-2300 way back in 2004, it was a THX certified premium quality top of the range product. The Logitech engineers in the lab where given a clear goal i.e. to create the best 2.1 multimedia speaker system for the computers. They were not concerned about the price, they were more concerned about the performance & quality which lead in using premium quality components, be it electronic components, speakers used, wooden casings of the subwoofers, plastic casings of the satellites and even the wires used to connect the components. Price was never an issue, performance was. This single mindedness of the engineers produced a unique product, and Z-2300 was born.

If you consider that way back in the year 2000 when Logitech was known as a cheap speaker manufacturer and could not even meet the standards of Altec Lancing let alone Klipsch computer audio products, they made a huge effort back then in order to make a big step forward and used better quality components for their THX certified audio system lineup than they have ever done before thus increasing cost. My "Price was never an issue, performance was" statement is in context of my above view. Today when we compare the Z-2300 from an el chepo manufacturer Logitech with the HiFi maker company like Klipsch producing Promedia 2.1 as a computer multimedia speaker system, you find both of them being in the same segment going head to head in terms of audio performance and in many occasions Z-2300 coming out as a clear winner. Atleast we have to give credit to Logitech that that could produce a multimedia speaker system that can meet the standards of a Klipsch product. I give full marks to Logitech only for this effort.



Logitech Z-623 


Logitech introduced Z-623 in 2010 six years after Z-2300 reign. Actually I cannot recall of a 2.1 PC speaker that remained at the top of the performance charts for straight six years. They had to make the successor not because Z-2300 was getting old and becoming incompetent, believe me it is still is the king, but because the rival manufactures like Altec Lansing, Edifier, Creative, Sony etc are producing cheaper sets of same wattage and same configuration and labeling them as their premium product. Also 2.1 speakers sets are no more the cash cows of audio manufactures, rather these companies makes a lot of profit from selling the 5.1 & 7.1 speakers sets.

Z-2300 Specifications 

Audio Quality Certification: THX certified
Total RMS Power: 200W [FTC Rated Power]
System THD: Better than 0.05% before clipping 
Total Peak Power(RMS): 400W < 10% THD
Power distribution: 120 W (Subwoofer) + 2 X 40 W (Satellites)
Subwoofer: 120 W @ 8 ohms @ 10% THD @ 100Hz
Subwoofer Size (inch): 8
Subwoofer Type: Long throw
Satellites: 80 W (2 X 40 W) @ 8 ohms @ 10% THD @ 1kHz
Satellite Size (inch): 2.5
Satellite Type: Polished aluminum phase plug driver
Frequency response: 35 Hz - 20 kHz
Signal to noise ratio(SNR): @ 1kHz > 100dB
Sound Pressure Level (SPL): 117db
Subwoofer dimensions(HWD): 11" X 11" X 15"
Satellite dimensions(HWD): 6.75" X 3.5" X 6"
Total weight : 15 Kg

UNPACKING

The satellites & Control Pod neatly packaged in the box




SUBWOOFER



The subwoofer is huge, in every sense of the word. The behemoth measures 11” (H) X 11” (W) X 15” (D), and its output could rattle the paint off your walls.

To give a comparison of how big the subwoofer is, look at the picture below where the Z-2300 sub is kept aside Altec Lansing VS2421.



Subwoofer made of thick MDF


The wall of the sub is made of 16 mm thick medium density fiberboard (MDF) which is quite impressive. It has been further strengthened with internal clamps in the joints. This adds tremendous strength to the box in order to withstand the slamming, heavy duty sound waves produced by the bass driver. The subwoofer weighs 12 kilograms and is a back breaker for sure.

Actually, this subwoofer was designed for Z-560 way back in the year 2000. Z-560 was the first THX certified multimedia speaker system from Logitech and was a big gamble at that time. Nobody was quite sure how the market will react in accepting a high end computer speaker from this unknown brand. But it seems that the gamble finally paid off and ever since this Holy Grail subwoofer have been used in their THX certified speaker systems line up for the past decade as below:
Z-560 [first THX certified 4.1 system, launched in the year 2000]
Z-680 [first THX certified 5.1 system, launched in the year 2002]
Z-2200 [first THX certified 2.1 system, launched in the year 2003]
Z-2300 [second THX certified 2.1 system, with minor updations on Z-2200 launched in the year 2004]

Z-2300 Bass Driver


Z-2300 subwoofer has a front facing massive 8 inch long throw bass driver. It has a Rated Power Input of 80W and maximum power input capability of 160W.

This history of 8 inch bass drivers began when Logitech choose Tang Band as the OEM manufacturer for their first THX certified multimedia speaker system Z-560 way back in the year 2000. It used direct off the shelf 8 inch Tang Band W8-670C with rated power input of 80W, maximum power input capability of 150W having a max excursion capability of 7mm. I guess at the time of release, Logitech was entering a new domain in computer audio, changing their image from relatively ordinary PC speaker manufacturer to a high end computer speaker manufacturer, and was themselves not quite sure about how many units of Z-560’s they will be able to sell.

There is a department in Logitech that exclusively deals with audio products and are better known as Logitech Sound Central. The link to the website is provided here: Logitech Sound Central

They state: “We don’t simply buy parts off the shelf. We laser tune different types of drivers. We modify the shapes, experiment with materials, and use digital components to improve sound quality. Our goal is to deliver fidelity as close to the original sound as possible.

Logitech Sound Central testing the bass driver of Z-5500


When Z-560 successor, Z-680 was launched in the year 2002, they shifted to an unknown speaker manufacturerwhich builds speakers in accordance to Logitech specifications.

I personally own a Z-560 & Z-2300. After minutely inspecting both the drivers of Z-560 & Z-2300, I found out

1) Both have same magnet size & weight thus having identical rated power handling capabilities.

2) Z-2300 bass driver have more excursion capability that that Z-560 ones, maybe 10mm [estimated] where Z-560 ones have only 7mm. This is evident since Z-2300 ones have slightly longer & elongated stamped steel basket section between the spider & the magnet compared to Z-560 ones, providing the space for more excursions capability.

3) The cooling efficiency of the Z-2300 bass driver with its bigger vented pole piece is significantly higher than Z-560 ones.

The bass driver of Z-2300 with even higher excursion capability than Z-560 ones will definitely offer better sensitivity & accuracy not to mention the ability to handle more power over its rated input power with better cooling efficiency.Later I found out that Z-2300, Z-2200 & Z-680 all used this new driver.

Look below at the increase of the hole diameter of the vented pole piece:

Tang Band Z-560 subwoofer with smaller vented pole piece 


Z-680 aka Z-2200 aka Z-2300 subwoofer with bigger vented pole piece


Z-2300 Bass Driver 












Comparing Z-2300's aka Z-680 monstrous 8 inch bass driver on the left with the Onkyo's 8 inch bass driver on the right.



Note: Normally people confuse this bass driver as used in Z-680, Z-2200 & Z-2300 with the Tang Band W8-670Q model. Though both units look near identical, Z-2300’s bass driver is different from the W8-670Q in the rear section. It became absolutely certain when my friend’s Z-2300 bass driver went dead and I have to personally contact TangBand via email to ask the model of the driver used in Z-2300 & its price. I also send them the above pictures of the driver to help them identify. To my surprise, they replied after inspecting the pictures sent to them, that this bass driver do not belong to them or in any way or represent any one of their models. But they did agree that they supplied W8-670C drivers for Z-560. So, you see Z-680, Z-2200 & Z-2300 are not TangBands. Prior, I was also the victim of this case.

The subwoofer enclosure also houses a patented “U” shaped exponentially increasing bass reflex port to produce distortion free deep and rich bass experience. The enclosure is very deep, which is obviously good from an acoustical standpoint.

Z-2300 Satellites

Z-2300 uses 2.5 inch polished aluminum phase plug drivers in their satellites and are beautifully crafted to look like a piece of art. The 12W satellite drivers that Z-2300 uses are again from an unknown speaker company and does not in any way relate to 3 inch Tang Band (W3-594SB) units. I estimate a rated power of 10W & a max of 20W. But since these drivers get audio frequencies ranging from 150Hz to 20kHz, the power handling capability increases by at least two times. So these speakers can handle anything between 20W to 40W.

Satellite Drivers







With the polished aluminum phase plug drivers helping to reduce the path length differences about the cone surface, you get a smoothing and reinforcing the frequency response, particularly in terms of the highest frequencies the driver is capable of. There is some thermal dissipation one gives up by doing this, but the phase plug itself can serve as a heat sink for the voice coil and magnet pole.

CONTROL POD



The control pod of the Z-2300 is quite simple and minimalistic, which I prefer. No fancy lights just a big volume knob, a bass control, a 3.5 mm headphone jack, power LED and a power button. You can keep the control pod on your desk where ever you like and the controls are very convenient.

Here are some pictures of Z-2300 control pod innards





AMPLIFIER DETAILS 

Audio design has always been a subject that stirs the passions of most electronics engineers and a subject where the pursuit of perfection has many times comes before considerations of cost. That aside sometimes the simplest circuits can offer the best solutions in terms of cost and performance. Z-2300 houses the amplifier in their subwoofer assembly.

Power Supply

The power supply of an audio amplifier is of vital importance, since it provides all the juice required by power amplifiers to drive the big speakers. An underperforming power supply will seriously limit the performance of an amplifier.

The power supply consist of:

i) A center tapped toroidal transformer manufactured by Ten Pao International. This transformer is rated at 150.9VA with +/- 20.1VAC secondary, 3.75A.

ii) A metal cased bridged rectifier to provide full-wave rectification from +/- 20.1 VAC to DC.

iii) A pair of CapXon 10,000 uF, 35V capacitors one for + 20.1 VDC and the another for – 20.1 VDC acting as ripple filters in order to smooth the DC output.

Toroidal Transformer Details

Manufacturer: Ten Pao International Ltd.
Part No: Z-2200 EU
Model No: TOG433028F0
VA Rating: 150.9 VA [Confirmed by Ten Pao]
Primary Input: AC 230V/50Hz
Secondary Output Voltage: AC 20.1V x 2
Secondary Output Current: 3.75 A
Diameter: 95 mm
Height: 45 mm





A toroidal transformer uses a doughnut shaped core & is much slimmer than a conventional (EI) transformer. It has numerous advantages over EI type such as low weight, low hum, low noise and also being smaller in size than an equivalent EI type. On the downside they are much more expensive than a conventional EI transformer. But it is worth the pay since you get better performance. A toroidal transformer has so many other performance advantages over EI type that it is hard to describe here other than to provide the performance ratio. Toroidal : Conventional(EI) :: 158 : 5 . It you want to know more in details go to the link below:
Bryston Transformers

The Bridge Rectifier


The Ripple Filter Capacitors



The transformer used here is rated to have an output of two times 20.1VAC when it has its rated load. So its resistance has already dropped the open circuit voltage and its peak will be 1.414 times higher which happens to be 28.4VAC. A single rectifier here drops it by 1VDC to 27.4VDC and smoothing the ripple by the power capacitors drops it by another 1.4VDC to 26VDC.

So, DC voltage supplied by the power supply is +/- 26 VDC, the current being 3.75 A. 

Amplifier Chips

Z-2300 uses four Class-AB power amplifiers from STMicrolectronics. STMicrolectronic is a very renowned name in audio amplifier market.

The amplifiers used are:

i) A Japan Radio Corporation’s JRC-4565 operational amplifier. JRC-4565 is a dual op-amp which means it has two op-amps inside it to handle stereo channels.

ii) Two voltage regulators a 78M18 and a 79M18 supplying +/- 18 VDC respectively to feed JRC-4565 op-amp from the +/- 26.4 VDC power rail.

iii) One STMicroelectronics, Class-AB, 60W, TDA7296 power amplifier for each of the two satellites while the other two STMicroelectronics, Class-AB, 80W, TDA7295 are bridged together powering the subwoofer.

JRC-4565 operational amplifier 



78M18 and 79M18 voltage regulators



Logitech Z-2300 Amplifier Innards













Reasons for using Class-AB Power Amplifiers

A quick look at many new low power speaker amplifiers on the market highlights the move to Class-D audio performance, but when it comes to low distortion and low noise and best sound quality, Class-AB still has the edge.

Class-AB architecture offers a signal to noise plus distortion ratio of up to 10 times better than its equivalent Class-D neighbour as well as providing a much simpler architecture which can be tweaked as required, without the need for reactive filter components on the output and the electromagnetic radiation resulting from an output stage switching at a few hundred kHz. Class-D amplification has inherent distortion in it and therefore is predominantly used in lower bandwidth amplification like in subwoofers. In other words it is quite impossible for a Class-D to achieve the level of linearity in frequency response produced by a Class-AB amplifier.

Ultimately it comes down to what you want, for efficiency and cost effectiveness Class-D are best, but if you are ready to sacrifice some efficiency & increase cost for the sake of sound quality then Class-AB are the best. In other words Class-A amps sound the best, cost the most, and are the least practical. They waste power and return very clean signals. Class-AB amps dominate the market and rival the best Class-A amps in sound quality. They use less power than Class-A, and can be cheaper, smaller, cooler, and lighter. Class-D amps are even smaller than Class-AB amps and more efficient, because they use high-speed switching rather than linear control.

The most important reason behind which multimedia speaker manufactures are switching from Class-AB to Class-D is to increase profit margin. Class-D is very cheap to produce and does not need require a big extruded aluminum heat sink or expensive toroidal transformers. They are basically switching power supplies but utilize pulse width modulation so as to be able to reproduce and amplify an alternating current. There are ok for subwoofers, but I honestly think that it is ridiculous to use a Class-D amplifier in a high end studio monitor.

In short, Class-D amps are more efficient but are only good for low frequencies applications like subwoofer amplification. Class-AB amps can be used full range amplification i.e from 20Hz – 20kHz. Class-D amps cannot be used on highs frequency response because they only produce square waves because of the technology involved, so they will make your highs sound lifeless and tinny. Class-AB amplifiers produce full variable signals and can capture subtle nuances better, sound warmer and generally have more depth in their sound.

Principles of Amplifier Operation in Z-2300:

1) A stereo audio signal comes in through the green 3.5mm audio connector with the control pod.

2) In the control pod, the signal passes through the main volume logarithmic potentiometer for attenuation.

3) This attenuated audio signal is then send down from the control pod to the subwoofer enclosure through a D-Sub connecter where the amplifier module exists. A JRC-4565 operational amplifier first receives this audio signal. The JRC-4565 having stereo handling capability distributes the audio signal into two places:
a) To the left and right satellite TDA7296 power amplifiers and then subsequently to the 2 satellite speakers.
b) Back up to the remote through the D-Sub connector.

4) Inside the remote, the stereo audio signal is split again:
a) To the headphone jack
b) To the subwoofer bass volume potentiometer (where it is combined to mono at this point)

5) Audio signal output from the subwoofer bass potentiometer finally gets fed back into the subwoofer enclosure through the D-Sub connector to the bridged TDA7295 subwoofer power amplifiers and then to the bass driver.

The four power amplifier chips operate at 8 ohms load in Z-2300 amplifier module.

Technical analysis of Class-AB, STMicroelectronics of TDA7295 & TDA7296 DMOS Audio Amplifiers 

The TDA7295 & TDA7296 are both monolithic integrated circuit in Multiwatt15 package, intended for use as audio class AB amplifier in Hi-Fi field applications (Home Stereo, self powered loudspeakers, Topclass TV). Thanks to the wide voltage range and to the high out current capability it is able to supply the highest power into both 4 & 8 ohm loads even in presence of poor supply regulation, with high Supply Voltage Rejection. The built in muting function with turn on delay simplifies the remote operation avoiding switching on off noises. TDA7295 have a maximum output capacity of 80W while TDA7296 has 60W.

Remembering that the power supply of Z-2300 is +/- 26 VDC, the current being 3.75 A.

TDA7296

Output Power vs. Supply Voltage @ 8 ohms



Looking at the Output Power vs. Supply Voltage graph of TDA7296 above, we see it can produce 38W of power at 26 VDC at a respectable 0.5% THD.

So, at +/- 26 VDC --> 38W @ 0.5% THD @ 8 ohms 

Distortion vs. Output Power @ 8 ohms



Distortion vs. Output Power graph of TDA7296 shows that at 38W @ 0.5% THD @ 8 ohms @ 26 VDC it starts to clip & distort. So in order to produce distortion free sounds this id the effective maximum of the chip.

Effective maximum of TDA7296: 38W @ 0.5% THD @ 8 ohms @ 26 VDC

Power Dissipation vs. Output Power @ 8 ohms



The Power Dissipation vs. Output Power graph of TDA7296 shows it as a very efficient Class-AB amplifier. At 38W @ 0.5% THD @ 8 ohms @ 26 VDC, the power dissipation is just 12W. This means if 50W is fed by the power supply to this TDA7296, it will deliver an output of 38W to the speaker whereas only 12W will be lost as heat.

So, this TDA7296 have an efficiency of 76% when it is producing 38W @ 0.5% THD @ 8 ohms @ 26 VDC. The power dissipation increases when the output power is reduced to half.

TDA7295 

Two TDA7295 are bridged together into an 8 ohm load to power the subwoofer. Each of these TDA7295 sees effectively a 4 ohm load when bridged into an 8 ohm load. If you bridge an amplifier, the available power is the power of a single channel into half the load impedance multiplied by two.

Output Power vs. Supply Voltage of a single TDA7295@ 4 ohms 



Looking at the Output Power vs. Supply Voltage graph of a single TDA7295 above, we see it can produce 65W of power at 26 VDC at a respectable 0.5% THD.

So, at +/- 26 VDC --> 65W @ 0.5% THD @ 4 ohms 

Now if we bridge a pair of TDA7295, the available power is the power of a single channel into half the load impedance multiplied by two. Since TDA7295 produces 65W into 4 ohms, bridged it will produce 65 X 2 = 130W into 8 ohms.

So, at +/- 26 VDC a pair of bridged TDA7295 will produce --> 130W @ 8 ohms 

Distortion vs. Output Power of a pair of bridged TDA7295@ 8 ohms 



Distortion vs. Output Power graph of TDA7295 shows a pair of bridged TDA7295 after 100W starts to clip & distort. So in order to produce distortion free sounds this 100W is the effective maximum of the bridged TDA7295.

Power Dissipation vs. Output Power of a single TDA7295@ 4 ohms 



The Power Dissipation vs. Output Power graph of TDA7295 shows it as an efficient Class-AB amplifier. At 65W @ 4 ohms @ 26 VDC, the power dissipation is 30W. This means if 95W is fed by the power supply to this TDA7295, it will deliver an output of 65W @ 4 ohms to the speaker whereas 30W will be lost as heat. In a bridged format it will deliver an output of 130W @ 8 ohms to the speaker whereas 60W will be lost as heat.

So, a pair of bridged TDA7295 have an efficiency of 68% when it is producing 130W @ 8 ohms @ 26 VDC. The power dissipation increases when the output power is reduced to half.

Looking at the above figures its seems that Logitech’s claim of 200W is true, since each satellites will have 38W while the subwoofer will get 130W which sums up to: 38 + 38 + 130 = 206 W @ 8 ohms @ 26 VDC

But, unfortunately that is not the case.

Z-2300 amplifier’s continuous power output capability 

In order to produce 200W of continuous power, an amplifier will need a transformer that is capable of to deliver a minimum of 1.27 times the claimed wattage. Since Watt is volts multiplied by ampere, 200W of output requires 254 watts or 254VA transformer as a minimum requirement.

So, Z-2300’s supplied 150.9VA will produce a maximum of: 150.9/1.27 = 119W =~ 120W of continuous power @ 8 ohms @ 26 VDC

Since the ratio of power distribution between the subwoofer and the satellites are in the order of 1.71:1, the subwoofer will get 76W of continuous power while each satellite gets 22W of continuous power.

This becomes even more evident from the fact that the bass driver has a rated input power 80W, while the satellite speakers can handle anything between 20 to 40 watts.

The Total RMS Continuous Output Power of the four amplifier chips = 50(TDA7295) + 50(TDA7295) + 30(TDA7296) + 30(TDA7296) = 160W whereas the Total RMS Continuous Output Power of these four amplifier chips is 120W for Z-2300 since the the power supply limits the maximum power output.

Also these amplifiers will produce a lot of distortion & noise at the peak 160W power output. So, in order to produce distortion free, linear sound the amplifiers generally needs to reduce its output peak power by 25% or more. Using an amplifier with some extra “headroom” will help assure that only clean, undistorted power gets to your speakers. Reducing the maximum power from 160W to 120W Z-2300 creates a 25% headroom and justifies the stated system THD of better than 0.05% before clipping & signal to noise ratio of > 100dB.

Discrepancies about Power Output Figures 

Remember that most audio amplifiers do not have power supplies capable of driving their rated power continuously. This holds absolutely true for all computer multimedia speakers systems & consumer home audio products. Only HiFi systems costing a lot of money have power supplies that can match the continuous power rating of the amplifiers.

This is because music is not like a continuous sine wave. It has peaks of intensity, then relatively quiet periods. If music has a 20dB dynamic range then if the peaks are 200W, the average power is probably around 5W.

A transformer can sometimes go well beyond its rated power output for small amount of time to handle these peaks of intensity. For example the 150.9VA transformer of Z-2300 can go up to 180VA to handle the peaks & produce 140W power for that moment.

If even further power is required to handle this peaks of intensity, say 200W, then the additional 60W is supplied by the two large 10,000uF, 35V power supply filter capacitors of Z-2300 for this short period of time. The filter capacitors can charge back up during the relatively quiet periods.

So the 150.9 VA transformer of Z-2300 is perfectly capable to deliver 120W of continuous power & can easily handle peaks reaching 200W.

That is the reason why Logitech states that Z-2300 have a Total RMS Power of 200W. Look at the absence of the “continuous” word. Except HiFi systems, you will always find these consumer audio companies talking about “FTC Rated Power”,“Total RMS Power”, “Power”, “Total Peak Power”, “System Power”, “Music Power”, “Peak Music Power Output (PMPO)”,…………….. and the list goes on. But you will never find them talking about “Continuous Power” which happens to be the actual power of the amplifier.

Why Z-2300 is still the king of all 2.1 Multimedia Speaker System

Z-2300 is capable to produce 120 watts of continuous power which is a lot of power for a 2.1 PC speaker. Also, it is way more powerful than any of its competitors.

Look at the two shots of the Logitech Z-Cinema 2.1 speaker system power supply.



Take at even closer look at the main component of the Z-Cinema's switching power supply :



It is clearly stated, MAX TOTAL OUTPUT POWER 83.3W

Z-cinema’s switching power supply is capable to deliver a maximum of 83.3 watts which equates to 75 watts of continuous power from the amplifier. Also switching power supply cannot be overloaded the same way as transformers. In comparison, Z-2300 toroidal transformer alone is capable to produce 150.9 watts of power, not to mention it can even go up to 200W with the help of its internal capacitance & power supply filter capacitors to handle transient peaks on demand. So, on an average Z-2300 have 45W more than Z-Cinema. Same theory goes for the Z-2300 successor Z-623 which I believe is down by 40 watts or so.

Another famous example is Sony, notoriously known for their power out figures. Consider the case of Sony SRS DB-500 with 300W power output claim. A very famous website did a complete tear up of this DB-500 only to find out that the power supply can produce a mere 65 watts. So how does a 65W switching power supply produce 300W? Well even Sony is unable to answer this question.

So, the more you dig, the more you find out these power figures are marketing jargon, rather than true figures on which one can measure the performance of an audio system. 


THX CERTIFICATION

THX stands for Tomlinson Holman’s eXperiment. A THX Certified Multimedia Speaker system is designed for those who crave the power and performance of home theater and studio sound at the desktop.THX certification recreates peak, Reference Level quality at your desktop listening position.

What is Reference Level? THX Reference Level, a setting designed to mirror the exact volume level used by movie makers and sound artists in the studio. When you are watching a movie on a THX Certified Multimedia Speaker System, you experience every sound element exactly like it was produced by the filmmaker—with the same fidelity, detail and clarity.

Speakers that can achieve THX Reference Level is no simple task. It requires a tremendous amount of power to drive an audio system effortlessly without clipping or distorting. THX Certified Multimedia Speaker Systems are designed to recreate Reference Level with minimal distortion.

THX worked closely with Logitech during product development, ensuring the two-satellite and subwoofer Z-2300 & Z-623 speaker system was meticulously mapped to THX design standards. Then, THX performed more than 400 bench tests, including frequency response, noise, distortion and power. The result is a THX Certified Multimedia Speaker system that delivers THX Reference Level sound pressure and fidelity – letting you hear every bass note, sound effect and dialogue as it was created in the studio.

Performance Benefits:
400 Bench Tests: THX acoustic and electrical bench tests ensure accurate and powerful audio performance.
THX Reference Level: Designed to mirror the performance characteristics of professional studio speakers, recreating peak, THX Reference Level quality.
Wide Bandwidth: Low frequency extension of satellite speakers ensures a smooth and balanced audio experience when sound pans from satellites to subwoofer.
Desktop Engineered: The Logitech Z-2300 or Z-623 are perfect for PC gaming, podcast production, audio and video editing, and enjoying music and movie applications on your desktop.

PERFORMENCE

1) QUOTES FROM DIFFERENT WEBSITES

i)Tomshardware

"Pump Up The Volume With 117 DB SPL

The response showed good balance and remarkable regularity in the midrange of up to 10 kHz. After that, performance slipped a little, which is to be expected from full-range drivers. Obviously the low end was nice and deep, which is normal for an enclosure of this size equipped with a good woofer and amplification. The 2300 isn't open to much criticism in this department."

SPL Figure Graphs 

Satellites


"Response was remarkable in the upper part of the spectrum, even if the third-octave weighting linearized it somewhat. The hiccups in the lower end of the spectrum were largely due to the room where the measurements were made and should be ignored."

Subwoofer


"The 2300 handles the entire lower register. Like its predecessor, it can reproduce very low frequencies without weakening.

The Z-2300, based on Logitech's 2200, will serve as a reference point in the world of high-performance 2.1 speakers. While we would have preferred to see the satellites offer two-way drivers, the final result is that the speakers are at the high end of the quality spectrum. The 2300 thus represents one of the rare possible choices in this product sector for those who seek the best in the category."

ii) Tech-Labs (Russian)

Frequency Response

"Subwoofer little nedotyagivaet to lower the declared value, although both show a great result - 45 Hz. However, his characterization is not perfect, we can state a clear peak and the absence of a "shelf". The satellites, show a fantastic uniformity. Over the entire operating range it does not exceed ± 2.5 dB. For full range satellite speakers in the multimedia speakers category, such a result can be considered the supreme achievement."

Harmonic Distortion

THD Subwoofer

"THD of the subwoofer is very low even at high volume, they do not exceed 10%."

THD Satellites

"The tiny full range drivers perfectly wins back a wide frequency range, it develops impressive power too."



Fs = 42.95 Hz
Re = 7.80 ohms [dc]
Le = 7328.42 uH
L2 = 3120.63 uH
R2 = 52.25 ohms
Qt = 0.52
Qes = 0.57
Qms = 6.49
Mms = 50.81 grams
Rms = 2.112233 kg / s
Cms = 0.000270 m / N
Vas = 10.35 liters
Sd = 165.13 cm ^ 2
Bl = 13.755757 Tm
ETA = 0.14%
Lp (2.83V/1m) = 83.66 dB

"The resonant frequency is quite low, only 42 Hz. In sum, with a low Q factor is comparable to the use of acoustic design. Also, thanks to a massive system of magnetic head has a truly outstanding power factor."





"On set of indicators above, our assessment of today will be strictly positive. Z-2300 has an excellent manufacturing quality and very easy to use because of the remote volume control. The sound quality which i am not afraid to say, the highest. Massive subwoofer reproduces deep & rich bass that perfectly complemented by bright sounding satellites. Despite the relatively small size, power acoustics really high, we can say is very high. According to test results Logitech Z-2300 receives the award "Editor's Choice" in its class.

iii)CNET

"Editor's Rating: 4/5
Design : 9/10
Features : 9/10
Performance : 9/10

The Good: Outstanding audio quality; streamlined, efficient design; adapter for game consoles.

The Bad: Upward-firing satellites not adjustable; hardwired cables.

The Bottom Line: Logitech's Z-2300s have been on the market for more than half a decade, but these PC speakers still pack a sonic wallop."

iv) 3DXtreme

"A set of Speakers is hard to review, because there is no way to present comparisons, charts and graphs. Here is what we can say – for about $110 I have not heard a better set of speakers at this price point. We’ve reviewed a few budget sets of speakers that just fell short in the sound category lacking clarity and bass. When this set came along it was like a breath of fresh air. It may not have the volume or the power of the Z-6800 (which I also have) but on their own they sound amazing. Watching movies, listening to music and gaming is all a great experience with these speakers. Keep in mind they are only 2.1 channel speakers however this set of speakers has the Lucas THX certification – I’ve found that speakers with this certification to be a notch above the rest of the other products found on the market. Maybe I’m spoiled by Logitech and their speakers but to me this would be a worthwhile $100 purchase for anyone looking to get the most for their money. Logitech even throws in an adaptor that will allow the user to connect these speakers directly to a DVD player or game console.

Pros
Great sound.
Incredible bass.
SoundTouch with headphone jack.
Logitech quality.
Cons
Short wires on the satellite speakers
"
v) Bildochljud.se

"Sound Quality [Translated using Google Translate]
Here we are really surprised. Logitech's holding is not so much from the crowd in a negative sense as we feared. The sound will not be near the B & W's or Harman / Kardon, but it actually costs Z-2300 just a fraction too. If we compare with Altec Lansing, we are actually prepared to say that Logitech do better. The balance between the satellites and subwoofer is better here. You can almost play as loud as you want and the subwoofer has a great rumbling that matches the satellites well. We heard no distortion when the volume was turned up properly and balance, like I said very good.Logitech handle sensitive music and hard rock in the same fine manner. This is simply a cheap alternative that provides excellent value for money. No one style icon, but in short, a good sound for a small amount. We like the Z-2300."

vi) pocketnow.com 

"OVERALL IMPRESSION
I've always been partial to offerings from Klipsch - I've owned many of their products, and to me they represent a very high level of quality. I expected the ProMedia 2.1 THX system to remain the king on the block even with, but as indicated by the ratings above, Logitech has brought to the market the next champion in high-end 2.1 multimedia audio namely the Z-2300."

2) MY PERSONAL THOUGHTS

Music: Throughout my 2 years with Z-2300, one thing became very clear; these are very neutral sounding speakers. What is produced by these speakers is very smooth, and very pleasant to listen to. The one thing that does come to mind when listening though is power. Z-2300 is capable of producing 117 dB which is a world record for a 2.1 multimedia speaker system. The subwoofer lets itself be known with its slamming tight & precise bass which at times are powerful enough to knock the wind out of your lungs. The satellites feature a nice, natural sound with excellent representation. If the user wants, they can boost the subwoofer levels through the roof though my ears will be bleeding by then.

I am dealing with one of the best solutions for pure listening pleasure, with a clean sound devoid of any colorings, embellishment or ornamentation in the sound, commonly found in Altec Lansing and Creative speaker systems. Now I can easily hear many of the previously obscure details in the compositions of a complicated music composition, and can clearly set apart all the instruments used in the music composition, thus I am able to focus not only on the primary instrument, which is audible, but also on the fact that what instrument I want to hear.

Even though these are not two way satellites, the phase plug allows the 2.5” driver to more accurately reproduce the high end of the frequency spectrum. There is no background noise with these speakers, and definitely none of the hiss that my Altec Lansing MX-5021 suffered from. The analog input was very clean, and it was able to reproduce the sound with great accuracy.

Movies: These speakers are exceptionally clear at reproducing dialogue, as well as action, in a wide variety of movies. Even when there is a lot of action and music on screen, dialogue is never drowned out, nor does it get muddy or indistinct. The lack of any kind of hiss also helps in playback, as the softer, more subtle scenes draw the viewer into the movie. The satellites do an outstanding job of reproduction.

When the action gets heavy, the subwoofer really kicks in. The bass is tight and strong, and it will make a user’s chest thump if the content calls for it. Low end effects can really help to heighten the tension of a scene, as well as help to expand the overall environment. The subwoofer on these speakers is able to handle nearly every explosive scene thrown at it. Never once did it sound like the subwoofer bottomed out, or sound strained, or even chuffed. The ported design is surprisingly quiet, considering in other designs I have heard quite clearly the air moving in and out. Overall, for a 2.1 set of speakers, these turned out to be quite good for movie reproduction.

Games: This is probably the area where these speakers excel the most. The satellites are very clear in gaming, and their mid-bass is very present, but not overpowering. High frequency sounds are usually not present in most games, so the lack of a tweeter here does not affect gaming performance one bit. The satellites are able to provide excellent sound in a variety of gaming situations, and the ability to accurately reproduce the HRTF effects makes for a very immersive experience.

The subwoofer really gets a workout from many of the new action games, and it keeps asking for more. In titles such as Need for Speed Undercover, the subwoofer plays a very large part in the action.

VERDICT

Z-2300 is hitting the end of the production cycle. It is the last of the titans which is finally going to take slumber. It has definitely the upper hand over its opponents namely Logitech Z-623, Altec Lansing MX-6021, Sony SRS DB-500, Edifier S530, Klipsch Promedia 2.1 & Creative Gigaworks T3 in terms of performance. Also Z-2300 is the clear winner in terms of performance/ price ratio.

When you put the Z-2300 in the above equation, everything falls loose. Z-2300 is like a lion among a herd of cattle’s named Z-623, DB-500, S530, Promedia & T3.

1) None of the above sets have the power output capability of Z-2300. Z-2300 is the loudest of the lot and makes the opposition eat the dust.

2) Z-2300 has wonderful power reserve in the amplifier & thus do not distort even at full volume. Z-623 & all the other sets distorts at full volume.

3) In terms of music representation Z-2300 is second to none. Since Z-2300 uses Class-AB amplifiers, the sound produced by Z-2300 is more natural, very well defined & represents the true analog nature of the human voice. Both male & female voices are excellently represented in Z-2300. In contrast Z-623’s Class-D amplifier lacks a little bit of the natural feel & warmth in the sound as found in Z-2300 and represents more that of MX-6021 & DB-500 in their sound characteristics. The subwoofer has tight bass but the overall bass of the Z-623 is not well defined. A system with Class-AB amplifiers (as in Z-2300) will produce bass which is a little less deeper than a Class-D of Z-623, but the bass will be much more defined & accurate and also feel more natural & real.

For example, playing the track "Chant" of the band Foreplay, I noticed that the kick drums of that track produce "boom boom boom" on the Z-623. Playing the same track on Z-2300, the kick drums sounded "booouuumm booouuumm booouuumm" which happens to be the actual sound of kick drums. In contrast, Z-623 bass goes a little deeper but is less natural & neutral.

If you really need a high end 2.1 THX certified multimedia speaker system don’t waste any more time and get a Z-2300 while it is still available. If it not available then only greet the new champ of the block, Logitech Z-623.