Manual
I wasn't impressed with the owner's manual. Step two under Installation Procedures reads, "Set the unit according to the intended usage." Captain Obvious (the apparent author) goes on to tell you to do things like "Connect the speaker wires." If you already know what you're doing, this is the owner's manual for you.
In all fairness, there are good illustrations. Unfortunately, the captions read like a conversation with someone who don't speak so good English. I wonder if the French and Spanish versions are better?
The warranty card is better and states that you have one-year parts and labor coverage for your new Kenwood amp. As always, keep your receipt in a safe place. You know, in that file folder with all your other warranty packets, registration cards, and receipts.
Listening
This is always the fun part. I set the unit according to the "intended usage" in the trunk of the LSE. That meant connecting the power, speaker, and RCA cables, setting the crossover around 85Hz, and turning the gain all the way up. Since I run a DVC 12-inch subwoofer in a sealed cabinet, I left the infrasonic filter off. If you have a ported sub box, definitely use the infrasonic. Choose the setting (15Hz or 25Hz) that's slightly below the port tuning frequency of your box.
I started with an old Flim and the BBs track, "Tricycle," to check the quickness and control of the amp. The tune starts with a very quiet piano line that dances along into a very loud kick drum and bass hit. Try it next time you're transporting an intoxicated buddy; it's a hoot. Note: You might want to install seat covers first. Back to the test-the hits were very tight and well controlled. So far so good.
Next up was "Planet Krypton" from my trusty Car Audio Nationals CD. This is a powerful symphonic piece, featuring lots of brass and, more importantly, very low organ tones toward the end of the track. The KAC-9104D hung in there until the last couple of low notes, where it lost control of the subwoofer and resulted in some sloppy "doubling" of the cone. It was still moving, just not with definition.
Out of curiosity, I popped in an Autosound 2000 test disc with sine wave test tones that correspond to the track number. I started at 10Hz and stepped it up one track at a time, listening to (and feeling) the subwoofer. The woofer seemed to become effective at 16Hz, and completely kicked in by 20Hz. I concluded that those organ tones must be at or below 16Hz.
OK, it was time to let the bass drop, so I dialed up track four, "Make it Drop," from my Bass Mekanik CD. This track was a lot of fun, as was the relentless beat on Yello's "Oh, Yeah." Overall, I was pretty impressed with the sound of the Kenwood amp. It's not a monster, but it does have better low extension than most $300 sub amps.
Conclusion
Even though the KAC-9104D was finicky, even irritating, on the test bench, you have to keep in mind that it's designed to be connected to a subwoofer, not a resistor. However, I was disappointed that I couldn't get close to the 900-watt printed spec. Coming from the bench test ordeal, I was very pleased by the performance in the car. Even though I could only squeeze 644 watts out of the unit, at $300, that's only 47 cents per watt, quite a value. It's big enough to be fun, with a price you can afford.