Kenwood has been around for a long time - as long as I've been involved with car stereo. The first subwoofer I actually "felt" in a car (early 1980s) belonged to a high-end Kenwood system. Back then it was just known as Kenwood, but now the best stuff from the company uses a suffix, Excelon. So how cool is the Excelon product? Let's find out with their new 5-4-3-channel amplifier.
The Kenwood Excelon KAC-X542 is an unregulated Class A/B model rated at 88 watts x 4 at 4 ohms, 124 watts x 4 at 2 ohms, and 270 watts x 2 when bridged into a 4-ohm load. Kenwood included a 12dB/octave variable (50-200Hz) highpass crossover for both A and B channel pairs, but upped the ante considerably for the B channels. Besides the highpass, it also has a 24dB/octave 50-200Hz lowpass crossover, a 24dB/octave infrasonic filter at 15Hz, and some digitally controlled equalization.
The cast aluminum chassis has a textured flat black finish with lots of visual features: an intake fan on the top; a digital display with control buttons; a black anodized aluminum cover with a brushed finish over the control section; and a row of "bosses" at the far side rising slightly higher than the rest of the amp that are cut and brushed to reveal the aluminum. All in all, it's very interesting to the eye, looking a bit like the top of a modern automotive engine.
All of the inputs and outputs are lined up along the near side of the amplifier. Looking at it from left to right, there are two 30-amp fuses, power/ground and remote turn-on terminals, Channel B and Channel A speaker terminals, an LX-bus connector (for directly connecting to certain Kenwood head units for control options), two S-video connectors (for controlling the equalizer sections in multiple Excelon amplifiers), two sets of RCA inputs and a single pair of RCA outputs. Sounds like a lot of stuff, but it looks pretty tidy when the cover plate is on.
The digital display on the top usually just displays the voltage, amp temperature, current or fan status. If you scroll through the menu, though, you get to the EQ functions for the B channels. There is a bass EQ, bass extension function, treble EQ and volume offset. The LX-bus and S-video connectors allow you to control multiple Excelon amplifiers from a "Master" amplifier, or control them all from an appropriately equipped Kenwood head unit. I think this is pretty cool, though there's little to no mention of it in the owner's manual or on the outside of the box.
Installation
The instruction manual is a 24-page A4-sized affair; eight pages each in English, French and Spanish. The manual explains how to install the amplifier, along with several precautions. There are pictures with extremely brief descriptions of what the features are.
In spite of its large footprint (10" x 17 1/2") this amp is a fairly straightforward installation. The mounting feet protrude out from the ends of the cast aluminum chassis and all of the wiring is done from one side of the amp. The terminals use Philips-head screws, and they are all clearly marked. Kenwood gives you a 1-year warranty, whether installed at a dealer or just bought over-the-counter.
Performance
Measured power was almost exactly the same as the specs in the owner's manual, with 2 watts per channel to spare at 4 ohms and also when bridged. I measure frequency response at the -1dB points, rather than the rated +0 and -3dB spec, but again it matches the spec very closely. I did not see any strange quirks on the scope or the frequency sweeps.
| Output power @ 1%THD, 1kHz, 14.4Volts |
| Stereo @ 4 ohms | 90 watts x 4 |
| Stereo @ 2 ohms | 124 watts x 4 |
| Bridged @ 4 ohms | 272 watts x 2 |
| Frequency response ( + 1dB) | 7Hz - 43.6kHz |
| S/N ratio (A weighted, below clipping, min gain) | >89dB |
| Maximum current consumption, unclipped | 60 amps @ 544 watts |
Conclusion
The MSRP of the KAC-X542 is a cool $400. Work out the math and this one comes in at just over $0.73/watt at its 544 watts of max power. The unit was well behaved on the bench, turned on quickly and has reliable protection circuits. It also measured extremely close to the specifications in the manual, which is admirable to begin with. I think this a pretty good value on its own, even better if used in conjunction with other Kenw od units that would capitalize on the amp control. Now if only Kenwood would do a better job expressing the potential of this amp, their competitors might have something to worry about.
Kenwood Excelon KAC-X542
MSRP: $400
Performance
Flexibility
Dollar Per Watt
Overall Value