Polk Audio I-Sonic Desktop Audio System

Polk Audio ’s new I-Sonic brings a wide range of music sources to a desktop or bedrom audio System —and does so with surprising sound quality. The curvaceous, nine-pound I-Sonic might look like a “table radio,” but appearances are only skin deep. The $599 I-Sonic is much more than a good-looker, both in terms of format capabilities and fidelity. In addition to including an AM/FM tuner, it is XM-ready (antenna and XM subscription required) as well as HD Radio-ready. (HD Radio is a free radio service delivered digitally by your favorite local terrestrial-based stations. HD Radio’s multicasting feature allows local radio stations to broadcast many “hidden” channels of different music. Find HD Radio stations in your area at www.ibiquity.com/hd_radio/hdradio_find_a_station/SA.)

The I-Sonic’s integral disc drive lets you play music CDs and even DVDs, meaning that it can function as the video source (via S-video and composite-video outputs) for a small home-theater system, offering greatly improved sound quality compared with your TV speakers. The I-Sonic is also compatible with Picture CD so you can display photos on your TV monitor.

In addition to the I-Sonic’s ability to deliver music and video from a wide range of formats (AM/FM/XM/HD Radio/CD/DVD), it can be connected to an external source such as an iPod or other music player through its stereo line-level input jacks. A nice feature allows you to store up to 30 radio presets in any combination of AM, FM, XM, or HD Radio. A dual alarm clock completes the package.

I particularly like the I-Sonic’s informative and useful front-panel display, top-mounted “soft” buttons that change function depending on which source is selected, and curvaceous, compact enclosure. In fact, the I-Sonic’s user interface and overall design are exceptionally well thought out.

None of this versatility would matter if the I-Sonic didn’t satisfy musically. It would not be an overstatement to say that I was shocked by how good it sounded, particularly when playing CDs. The most impressive aspect of its sound was its extremely smooth and flat tonal balance. Polk apparently didn’t play tricks with frequency response to appeal to a mass audience, such as boosting the upper bass to conceal the lack of low bass, peaking the midrange for greater “presence,” or brightening the treble to add “clarity.” Instead, the I-Sonic sounded like a high-quality minimonitor in its overall balance. This smoothness translated into a natural presentation that I could listen to for hours at a time (in my office while working) without fatigue. In fact, I replaced my office separates system (which included a pair of $600 mini-monitors) with the ISonic.

After I’d had the I-Sonic for a few weeks, Polk’s Paul DiComo sent me its frequency-response plot. (He was in the R&D area and noticed a response plot on a computer screen, and seeing how flat it was, assumed it belonged to one of Polk’s upper-end products. The engineer told the surprised DiComo that the response was that of the I-Sonic.) The plot is flatter than that of many freestanding speaker systems—and sounds that way.

The I-Sonic has other qualities going for it beyond a smooth and natural tonal balance. Bottom-end extension, weight, and definition are mind-blowing for such a compact system. Even with the lowermost octaves missing, the I-Sonic provides enough information in the bass to be musically satisfying. For instance, on the terrific new piano-trio CD Jan Lundgren in New York (a Japanese disc imported by East Wind Imports), Peter Washington’s marvelous, swinging bass playing was clearly evident and musically coherent.

The treble was also surprisingly clean and free from tizz, simultaneously sounding airy and extended. I would even go so far as to describe the treble as having a sense of delicacy and refinement. In addition, the I-Sonic’s four speakers (two forward-firing and two rear-firing) deliver remarkably similar tonal balance and spaciousness from anywhere in the room. It says much about the I-Sonic that I’ve described its sound quality in much the same way I would a high-end product. The I-Sonic is that good.