Review on Audio Amplifier Receiver Integrated Speakers by Jason Sluck

I've read good reviews for this little amp but it just didn't work for me. I felt that the distortion was audible at almost any volume and that it wasn't strong enough to be of any use. Since this is a class D amp, and cheap class D amps have a high output impedance in series with the speakers, I suspect the reason it sounded bad to me was because the speakers' frequency response was distorted by high frequencies frequencies was affected. output impedance. For those unfamiliar with this, this is a well-known phenomenon. The output voltage of the amplifier is divided between the speaker and the impedance (output impedance) connected in series with the speaker in a ratio equal to the ratio of the two impedances. Thus, at or near resonance of a woofer, where its impedance is typically five to ten times the loudspeaker's nominal impedance, the fraction of the amplifier's output voltage to the loudspeaker will be much larger than it is nominal at other frequencies. The same applies to the high-frequency resonance, which is in the middle range for most tweeters. It also affects the speaker crossover's ability to roll off the woofer output at higher frequencies, where the woofer should take over from the tweeter. Inexpensive Class D amplifiers therefore have a decisive disadvantage: loudspeakers with a flat frequency response become loudspeakers with a significantly poorer frequency response. Because of this effect and the higher than expected power compression (nonlinear distortion) I just didn't think this little Class D amp was good for much. That doesn't mean that all Class D amplifiers are inferior. Some of the best amps money can buy are Class D amps, but these are exotic Class D amps that are expensive. The reason they work is because someone figured out how to solve the high output impedance problem. Perhaps the trick is to use such a high switching frequency that only a very soft low-pass filter is needed to suppress high-frequency artifacts. Whatever the case, it's clear that high-quality, expensive Class-D amps are superior in every way, while these cheap little Class-D amps seem to be, er, I think "junk" might be the right word.