Hiya folks,

Well, I finally did it it! I spent many weeks trying to pick out an amp without being able to try it in my setup. That really is the biggest problem with car audio stuff, you can't try it before you buy it. Yes, I know about crutchfield and such, but I wanted to have it done locally.

So, I picked out my amp based on two things, specs (yipee) and opinions of the local shops. Most of the shops in the area seemed to agree that PPI is the best amp around (sorry, Pinky, but no one has cadence amps, and none of the local shops liked them, of course, I'm guessing thats because they don't carry them). I was supposed to get a Nakamichi amp, but everyone seems to think they went down the sh**ter.

I ended up with a PPI PC2200.2 installed for $270 (including tax). The amp has some of the best over all specs around 2x50 RMS, <0.02 THD, 110DB S/N, etc... The amp is inside the spare tire and seems to handle the heat very well. I went on the bay area drive yesterday (about 2hours of continuous driving) and the amp never overheated... Crystal clear audio even when going around a 120 degree turn at 35+ .

O.k. now on to my HIGHLY SUBJECTIVE review of the Kenwood KFC-XR600s at recommended power (5-45 WRMS).

Here are the iterations I've gone through with the Kenwoods:

Stock deck: Distorted at mid volume levels. Almost no clear sound when driving at speed with the top down. This setup was worthless for top down driving at 80+ MPH.

New Deck (19 WRMS) single channel in parallel to each speaker: O.k. now we are getting somewhere I can hear upper mids and a few highs at speed... (Now of course I'm working from memory here, its been a while since I had that setup). Not very good overall.

New Deck, bi-wired: More highs and less distortion down low.. blah blah blah, read the other thread .

New amp: Things are finally at what I would consider a good level, not great, but good all around. The mids sound much richer the highs are all there.. Yippee at speed Its almost as if I had the top up and was listening at normal levels!!!. But ut oh... lows are still a problem. The amp has a 90Hz crossover on it, with this on everything is fine... I can turn the gain up like a 10th of a turn or so and still have clear audio at max volume.

At first I didn't even notice the <90Hz freqs were missing, but of course I had to start tuning the amp (the installer had left the gain at max and I couldn't even turn the volume passed 20 outta 50 before the speekers started making farting noises at all freqs.

So, I turned off the crossover and heard (mainly felt) all the bass I was missing.... Damn it... I put the gain at 0! and now 90% of the music I listen to will be crystal clear at max volume. I still get random songs that just pump out notes these speakers can't handle. But hey 90% of my music clear... not too bad!

With the new PPI amp things are much better, but still a little bit below my tastes. I don't believe there is a shortage of power, so, I'm gonna have to blame the speakers for the distortion at high volumes... It seems like every thing I do only makes it a "little" bit better.

I'm throwing out a wild guess here, but I don't think I'm using anywhere near 50 W when the speakers start farting. I'm not sure what the gain to deck correlation is, but my gain at 0 can still cause distortion (o.k. sure my deck could be putting out a signal voltage which makes 0 gain 50W, but I tend to doubt it).

My conclusion is this, the Kenwoods are great low to mid volume speakers, but they will never be able to get loud. At least not loud with the top down. I still enjoy being able to hear all the notes, so the amp was worth it. But, don't ever expect these speakers to pump up the volume .

Barry, I believe you said your deck was 27 Watts... and you can hear your speakers clearly with the top down... Sounds to me like you have already reached the upper limits of the kenwoods. It would be cool if we could get our cars together and compare, but alas we are many many miles apart. Any chance you are going to the S2K days in Cali?

Later folks!

-- Robert

 

Thank you, Robert, for doing the work.

I am disappointed with your report. My head, Alpine CDA-7876, is rated by Alpine as 60 watts x 4 channels peak, 27 watts x 4 channels rms. Also it has an optional high pass filter settable for off or 80hz or 120 hz or 160 hz. With the filter on, like with your cross over working like a high pass filter, I can hear the music clearly but missing the bass. With the filter off, I've got clear music at town volumes but not at highway volumes.

I've left my "bi-amp" wiring in for now. It didn't make much difference one way or another and, after all, I've got that 16 gauge wire installed, so I just left well enough alone.

Before your post I have been strongly considering having my stereo shop install the Alpine MRV-T407 2 channel x 60 watts rms amp. Now, I think I'll wait.

Perhaps I should try a different speaker, or rear speakers, or a subwoofer.

Barry