With a sound-pressure-level meter, a test CD, and a few fancy algorithms, the IL100s's RABOS can significantly reduce your listening room's bass anomalies. Infinity's Web site has a full white paper on the system. The company sells the necessary test CD packaged with a sound meter and other useful items for $60, but your dealer might lend that stuff to you. We achieved excellent results before we tackled RABOS. After diddling with the controls a bit, we measured the IL100s's impressively flat response in our room: +/- 1.5dB from 30Hz to 100Hz (it was down an additional 2dB at 26Hz). That's incredible performance for a $499 sub! Your results, of course, may vary.
The IL100s's inputs and outputs are adequate; the only thing that's missing is a high-pass filter, which would allow you to feed the speaker-level sound through the sub and out to small satellites in a music-only system. The 32-pound cabinet, available in maple-, cherry-, or black-colored vinyl-wrap finishes, feels a bit lightweight for a sub.
The Brits call feel-it-in-your-gut impact slam. That sort of thing is usually the province of 12- or 15-inch subs, but the 10-inch IL100s isn't the least bit shy about exerting its woofage in the service of slam. We fired up the big, fat kick drum that starts off Roy Hargrove's tasty Crisol Habana CD to check out the IL100s's speed and definition. While most subs can generate enough bass to sound credible, only the best ones delineate the sound of the beater whacking the drumhead. Reproducing the thwack requires precise control over the woofer, and the IL100s let us decipher every juicy hit.
The heavy-duty low-frequency effects punctuating the opening battle sequence in Saving Private Ryan don't ruffle the IL100s's composure one bit. It delivers solid, deep bass in the jolting thunder of distant explosions. Many subs blur and muddle that sort of sound, but the IL100s clarifies what's going on down there, and you can really hear the difference.
Things were going so well, in fact, we had to double-check the IL100s's price--yeah, it's $499. It might be the best--the deepest, fastest, most musical and room-adaptive--$499 sub you can buy. If you want all that oomph and more, check out its elder sibling, the 12-inch $749 IL120s.