I was looking at the specs of the KAC-X650d 5-channel amp. I've noticed that Kenwood amps aren't particularly known for their quality... is this why?

Rated RMS Power (14.4V)
60Wx4 (20-20kHz@0.08%) + 200W (20-200Hz@0.5%)
80Wx4 (1kHz@0.5%) + 300W (100W@0.5%) (2 Ohm)
160Wx2 (1kHz@0.5%) + 300W (100Hz@0.5%)

I was looking at JL Audio amps, all their THD ratings were 0.03%.

Is the quality of 0.5% vs. 0.03% sound noticeably different? Is this what makes Kenwood amps mediocre?

 

a variety of factors influence the quality and features of the amp. Sometimes Ratings of amplifiers are fudged up... with companies putting out numbers at strange voltages, or not even showing actual correct numbers...
how do you know if it is quality?
I go by personal experience and the faith in forums like this one
also some have better power supplies, circuitry, and beter crossovers...

 

I use a kenwood amp.

its not horrible, but its not top quality either. They're one of those bang for the buck brands.

If you don't want to buy sony or pioneer, but you don't have the money for JL audio or RF, I'd suggest kenwood.

but if you want it to sound really good, I'd suggest JL audio.

example: I had my kenwood amp (I can't remember the model number, but its a recent one, with the built in fan, 800w peak power, selectable mono or stereo) hooked up to my kicker comp vr 12" 4 ohm subs in a sealed box. It was loud.

then I hooked up my JL audio 300/2 amp to my subs. Just a shade under the loudness of the kenwood amp, but oh-so-fucking-clean. It just hits louder on lower frequencies, especially with rap or techno. Like a good amp should

but ultimately, I'd suggest going to a good stereo shop and judging for yourself. We all have different ears, and we all listen to different music.

 

i bet u cant hear the difference in sound between thd .03 and .5 @ 1khz

the main difference should b power...
then like igo4bmx said...circuitry..xover..

but with most amps out there...there isnt much of a difference in sound if both do have the same power ratings...

i do believe..however...there is a difference in sound at really high volume
thats where dampening factor comes to play

 

also there are considerations about the type of amp you listen to.
i'm basically not happy with my class d sub amp (any class d amps i heard weren't as muscial as a class a/b amp

 

Same here with me. I have a 600 watt kenwood amp powering my subs and it gets the job done but not as well as a higher quality amp would.