While most people know Eclipse for their head units and amazing navigation pieces, they've been introducing innovative products to the market longer than most of us have been buying car stereo products. The Premium Digital series of amplifiers is a full set of Class D designs, some of which contain a cool twist.
The XA2000 is a full-range Class D amplifier rated at 100 watts x 2 at 4 ohms and 150 watts x 2 at 2 ohms. Eclipse makes use of Bang & Olufsen's ICEpower technology to dramatically extend the frequency response of a standard Class D design. The amp sports separate highpass and lowpass crossovers; a fixed subsonic filter and "paragraphic" bass boost equalizer; and a clipping indicator LED to help set the gain correctly.
Cosmetics
All dressed in black, the XA2000 uses a fairly standard extruded chassis, though it is accessorized with stylish carbon-fiber-look plates between the diamond-cut fins streaking across the top. The Eclipse logo is backlit and serves as the "power on" indicator. Gain and crossover controls occupy the forward part of the top while the connections are on the front edge of the chassis. The connections for the power and speakers are pretty cool - you insert the stripped end of the cable into the hole on the front and tighten the terminal with an Allen wrench through the top. The connection moldings are insulated, so don't worry if you forget to disconnect the power before fiddling with the wires (just kidding - always remove the power fuse before working on the wiring!). The unit is finished off with sheet-steel endplates and aluminum bottom cover, all finished in satin black.
Layout
The circuit board is a combination through-hole and surface-mount double-sided design. The high-current stuff is all through hole, while the control, signal level and ICEpower devices are all surface mount. The power supply and output stage hang-offs are along the back edge of the board as usual, but they are all bolted to two aluminum bars, which are in turn bolted to the chassis to move the heat away from the devices.
Battery power enters the amp by way of the previously mentioned terminals to the right, which consist of big brass blocks soldered directly to the PCB. The power terminals will accept up to 4-gauge cable. Power goes directly to a pair of 20-amp fuses and through a ferrite core inductor, then past 4,400F of capacitors to filter out any engine noise on the line. There is a large reverse polarity diode that protects the amp if you get the power and ground backwards. The transformer is a Litz-wound 1 1/2" ferrite core toroid driven at a frequency of 21.8kHz by four 50-amp Mosfets. By full-range amplifier standards, 21.8kHz is fairly low and can contribute to distortion, although it is more efficient. The ICEpower circuitry is designed to be less affected by this potential noise than straight-up Class D formats. A surface-mount TL494 pwm controller runs the show on the power supply side. The secondary winds of the transformer are rectified and filtered by 6,400F worth of capacitors and an inductor, resulting in + and - 36-volt DC rails available to the output devices.
In the middle of the front panel, signal enters through a pair of RCA connectors and then travels through the coupling capacitors and on to the vertical daughter board for gain and crossover processing. The input signal branches off to a dual op-amp feeding the "Preamp Out" RCAs. This is referred to as a "buffered" output, because the output signal is isolated, or buffered, from the input.
The crossovers make use of film capacitors and high-quality potentiometers along with the surface mount caps and resistors which have inherently high tolerances. The input RCAs are right next to the speaker terminals, and the corresponding circuit traces are very close together on the PCB.
Unfortunately, I feel that they may be too close and may contribute to noise and distortion. The signal passes on towards the rear of the PCB, to the ICEpower ICC1 and ICC3 chips that control the output devices. The output devices consist of four 32-amp/95-watt Mosfets for a total dissipation capability of 360 watts. The output passes through a pair of inductors, one per channel, and an output relay, and then on to the speaker terminals. The output relay is used by the controlling circuitry to disconnect the outputs during startup and during any protection situation.
Performance
The frequency response extended far higher than I had expected. Eclipse states 20Hz to 20kHz at + 1dB, but I found the response was still ruler flat up to 48kHz, which is the upper limit of my equipment. On the other hand, I was unable to locate a defeat switch for the crossover, so the low end is governed by the 30Hz highpass crossover and the fixed 18Hz subsonic filter. The resulting -1dB point is 40Hz, quite high in my opinion. The response is about 4dB down at 20Hz.
This is probably the most efficient amplifier I've ever had on my test bench! At one third power, 91% of the juice that goes into this amp gets to your speakers.
The crossovers and bass boost measured well above 40Hz, with nice straight slopes all the way down. In the lower frequencies things are pretty crowded. When you have a highpass crossover at 30Hz, another at 18Hz (the fixed subsonic filter) and the bass boost at 32Hz, it gets pretty messy. The bass boost uses a fairly low Q, but I'd recommend using it above 40Hz anyway for most subwoofers.
The XA2000 behaved itself very well under testing, but went into protection every time I tried anything funny, like large high-frequency square waves or lower-than-rated loads. The amplifier came out of protection each time and resumed normal operation without needing to cycle power to reset it. Listening tests revealed no turn-on or turn-off noise, and the oscilloscope didn't catch any spikes at all. You can hear a relay clicking, but it's not very loud. It wasn't audible when the amp was in the trunk.
Manual
The owner's manual is an 8 1/2" x 11" book with 24 pages. Although it covers multiple models, it's still very complete. There are lots of wiring diagrams as well as basic installation instructions and setup info. Much of the advanced tuning information assumes a high level of knowledge, but you can always drop by an authorized Eclipse shop for assistance. The warranty is one year parts and labor.
Conclusion
This amp sounds good, as good as many Class A/B amplifiers in the same price range. It is not as quick and brutal on my subwoofer as my reference amp (300 watts of expensive A/B power), but it does a good job. I'm still a little bewildered by the premature frequency roll-off on the bottom end, but I could live with it. I measured a maximum (unclipped) power of 380 watts. At a retail price of $349.95, that comes to $0.92/watt. That's higher than average for a 300-watt amplifier, but it has great sound quality and unbelievable efficiency. This amp would be a good match for a higher quality set of front speakers with an RMS rating of 100 watts or a subwoofer rated at 600 watts.