I find it hard to believe you havent been pulled up on the glaring factual errors and clear bias in your review, which to me makes clear you have little idea what you are talking about.
Your rant about class AB vs D - you make it sound like AB is the best thing that there is for a start. True 'money is no object' builds use class A. You say that class D cant reproduce accurate highs - then why is it being increasingly turned to by audiophiles - even for things like headphone amps wherre the highs are so crucial. I will admit i was dubious about class D when i first saw the crown class D stage amps well over a decade ago - 1kW amps the size of 100W class AB amps. they sound GREAT - you are unlikely to hear anything other than class D on stage now. You are also more likely to see class D than class AB in audiophile gear - class D is good enough to give class A a run for its money.
You talk about MDF like it is the ultimate speaker material. it isnt. Heavy Plywood is generally considered the best, thanks to its greater rigidity and crossing grain to prevent resonances. You say MDF is great because Chipbpoard disintegrates with moisture - i dont generally shower with my audio gear - bit if i did MDF would disintegrate and warp at least as quickly as the cheap, non waterproof LDF. There is of course plenty of waterproof chipboard around for flooring and marine and speakers that might get wet, as long as you dont just go for the cheapest option.
Your anaylysis of the Power - is as though it is from another planet. the 1.41 relationship has nothign to do with open circtuit or resistance. It is the relationship of the RMS (average) of a sinusoidal AC waveform to the peak of the waveform. A 1VAC waveform has peaks at +-1.41V. When you convert from AC to DC you become interested in that peak, the RMS value becomes meaningless. The 1.2V drop is the forward voltage drop of the 2 silicon diodes in series in the signal path on each half cycle within the bridge rectifier. Drop beyong that is from regualting circuitry (likely swich mode - aka class D amplifier at high frequency) which you skip.
we then get on to your TDA7296 graphs which clearly show that this unit crosses the 0.1%THD threshold (where amps are usually measured if they have any pretense at quality) at about 25W. It may hit clipping at 38W - but you should never measure at clipping, since that means you have driven WAY past what it can produce. It crosses the 1% mark (where the distortion becomes clearly audible) at ~32W.
TDA7295 " If you bridge an amplifier, the available power is the power of a single channel into half the load impedance multiplied by two." Just no - it just isnt true. - you tend to get about 1.8x the per channel power at best.
"If music has a 20dB dynamic range then if the peaks are 200W, the average power is probably around 5W." lol. 20db dynamic range means 100x difference between the peak and minumum. So the minimum would be 2W. you are saying the average would be 4db over the quietest part? What the heck are you listening to?
btw “FTC Rated Power” is continuous, for an hour, of a single tone, at full rated power, at 0.1%THD maximum. Done for several different tones. If it cant pass, then it doesnt have that power.
The enclosure and heatsinks of the z2300 are not up to dissipating the 50W odd that would be needed for the z2300 to do this even at 120W. So it is not 120WRMS continuous capable. it would overheat.
I love how you skip past the 1st graph of the russian lab test. It shows so clearly what i hear time and time again about Logitech systems.
That big twin peaked mountain.
The signature of a poorly designed heavily resonant ported bass enclosure. It not only is only loudest at that peak, but whatever bass you put into it will excite the resonant system at those 2 peaks, producing what is often called 'one note bass'. Sure, it is LOUD, and will rattle stuff, and inhale cans. But it isnt what was in the file you played.
Almost as bad is the big gap between where the sub rolls off and the satellites roll up, thanks to the lack of a midrange driver. A full 10db drop at 200Hz. the 5db drop at 10k is none too pretty either.
I am not saying that for the money, the Z2300 is bad. I am saying your review is.
For the money the Z2300 was a seriously decent system. But it was made to a budget. that is a good thing - normal people with normal systems can buy it. Cost is no object makes US$20,000+ which dont have any of those issues, but which you will probably never see in your lifetime. Musical perfection.
The sub makes LOTS of noise - in part thanks to that massive resonance
BOOM headshot
For the job it is designed to do on that budget - it is great
It has its failings, plenty of them. It has masses of design compromises.
But it is a lot of fun to have - and THAT is what matters. It is good enough for mortals to enjoy.
