Harman Kardon Signature Series 2.1 Multichannel Amplifier

• 100 watts per channel x 5
• High current, ultrawide-bandwidth design
• Low negative feedback and low harmonic distortion
• Auto turn-on triggered from HK Signature 2.0 preamplifier/surround processor
• Fanless cooling design

Manufacturers often slant their power specifications to make a given product appear more powerful than it is. Harman Kardon, however, doesn't need to fudge its specs for this dynamic, well-behaved, and (for its quality) reasonably priced five-channel amplifier. Some amplifiers actually decrease their power output when driving lower-impedance speakers; the Signature Series 2.1 gives you an honest 100 watts per channel (wpc) into 8-ohm speakers and 150 watts with 4-ohm models across the full audible bandwidth, with less than 0.03 percent total harmonic distortion when all channels are driven.

Keep in mind that speakers are rated at "nominal" impedances for the resistance they offer--the impedance of most speakers will vary widely at different frequencies and can dip down well below 4 ohms at certain frequencies. An amp that can't deliver its rated power at those frequencies, whatever they may be, will not sound as good or as powerful as one that can. The Signature 2.1 delivers more power at low impedances, not less. That means it has a beefy (and expensive) power supply.

Regardless of your speakers, you aren't likely to be driving all five channels hard, even during the most taxing Dolby Digital or DTS 5.1-channel movies. However, it's good to know that full power is available simultaneously at all locations if you need it. If your listening includes DTS 5.1-channel music CDs (or if you're planning to get into DVD-audio), you'll appreciate the power even more. Plus, when you're listening in two-channel stereo mode, you'll have plenty of sonic leeway.

The absence of a (usually noisy) cooling fan in the Signature Series 2.1 further exemplifies the great care that Harman Kardon has put into its design. Only careful parts selection and layout could allow this unit to properly dissipate heat without a fan.

But forget the technical mumbo jumbo: this is a fine-sounding amplifier at what is actually a very reasonable price: less than $300 per 100-watt channel. The overall sound of the Signature 2.1 is neutral, with slightly dry (or deaccentuated) mid and high frequencies and well-controlled bass.

Some amplifiers sound harmonically rich, or luscious, but at the expense of transient speed and detail (as you'd need in reproducing a drummer's dynamic rim shot). Other amplifiers sound "fast" but overly dry, lean, and analytical. The 2.1 tends toward this latter group relative to other equipment in its price range but still renders movies and music with enough texture to sound full and satisfying. Harman's high-current design produces a punchy, dynamic overall sound, which is perfect for home theater applications.

As is often the case with matching components, the 2.1's sound perfectly complements the smooth and liquid sound of the Signature Series 2.0 preamplifier/processor. Put the two together and you have a synergistic combination that sounds better than either piece by itself. That said, if you're thinking about one or the other as an add-on to your existing system, either works great with many other brands of preamp/processor or amplifier.

Be sure to provide adequate ventilation for this high-power amplifier and plug it directly in the wall or amplifier socket on your power-line conditioner of choice. You should not use any extension cords. With enough breathing room, the 2.1 should keep your home theater happy for many years to come.

Pros:

• High-power, high-current, low-feedback design
• Clean, punchy sound
• No noisy cooling fan
• High build quality
• Auto-turn-on trigger when used with Harman Kardon preamp/processor

Cons:

• Large chassis requires even larger space for good ventilation
• Slightly dry top end (high frequencies)