Kenwood KAC-X40

[KU40 173]

This amp is rated 40x4 @ 4 ohms at 12 volts, and I think 70x4 @ 4 ohms at 14.4 volts. 100 x 4 @ 2 ohms. I bought it for $189 from woofersetc.com.

This amp definitely seems to put out a good amount of power. I was a little worried at first about the 40x4 rating, but it shows no lack of power. I don't have a way to measure it's actual output, but it certainly does more than that. The 70x4 rating seems more correct, if not more. It gets my JL XR components as loud as I need or would want them to go. The amp looks gorgeous IMO, I love the black. I also love the connections all on the one front side, makes for very easy installation, at least for me. Two hex-headed screws hold on a top plate that cover up the controls. This is something I've never seen before. It's not a negative, IMO, it's just different. It could be bothersome if you're constantly changing your levels, but I'm pretty much a set-it-and-forget-it guy, so I may never take the cover off again, who knows. It does make for a cleaner looking install, though.

The gain is very clearly marked, unlike most other amps. Most amps just have a "0" at one side and "6" at the other end, or whatever. I believe this one has 0, .3, .5, 1, 2, and 4 marked. The crossover is also equally marked, with I believe 40, 70, 100, and 200. The A set of channels has only the gain and high pass crossover settings, but the B channels has gain, high pass or low pass, and also has a bass boost feature. One thing that's nice about this bass boost is that it's variable from 40-100 hz (instead of fixed at 45 hz like most amplifiers), also very well marked every 10 hz or so. The level of boost knob is, again, from 0-12db and marked every 2 db or so. In short, the options on this amp are outstanding.

The amp sounds clean and clear, no problems there. The amp does have a fan, which is not very common for a 4 channel amp. This is the only bad thing I've found about this amp. The fan is a tad noisy. I have an Explorer so the amp is in the same airspace as I am, and when stopped and with no music playing you can just barely hear it. It's not a problem when moving or with music playing, however, and I can't imagine it being audible at all in a trunk.

I was a little skeptical at first because it was a Kenwood, but they generally make their eXcelon line with pretty decent quality, and this amplifier doesn't miss the mark. Very solid.

[lithium 358]

thanks for the review. i own the x10d 600rms mono and it runs very nice aswell.