Pinnacle AC Sub 100 Subwoofer:
Page 2 A series of warble-tone tracks from Stereophile's Test CD 3 revealed an 8-dB bump over the reference signal at 40 Hz, as measured by a sound-level meter. This could be attributable to my listening room, or it could be the sub's design. Either way, this is where most budget subs hold their last stand. That generous output at 40 Hz, although clearly in midbass territory, rendered a pleasing, fully rounded low-level effect. The sub dropped off rapidly at 32 Hz, even though it kept fighting.

On back, you'll find a phase switch, a level control, a single line-level input, and a variable low-pass filter from 50 to 150 hertz.

The AC Sub 100 passed all of the special-effects tests: planes (Independence Day), trains (The Fugitive), and, of course, auto-mobiles (Tomorrow Never Dies). However, it could not replicate the true low bass that presses against your chest. It simply could not do justice, for example, to the "T-Rex Intrudes" chapter of The Lost World. It didn't blow me off the couch like some bigger drivers in bigger cabinets; then again, I didn't expect it to. Fortunately, it didn't have that intrusive, one-note effect typical of so many other budget models. Now that was a surprise.

The AC Sub 100 was more nimble and understated. It was the first budget sub I didn't have to either turn down or turn off when switching to music. It gave a more-realistic reading of bass transients than the others, if a little richer and slightly more sluggish than its more-expensive competitors. I subjected it to material ranging from Muy Divertido (Very Entertaining) by Marc Ribot Y Los Cubanos Postizos, an Afro-Cuban project by the New York guitarist, to rockabilly roadhouse legend Sleepy LaBeef's Strange Things Happening. LaBeef's basso profundo makes him the closest thing to a human subwoofer test tone.

The AC Sub 100 also steered easily through high-resolution-audio discs after I replaced the Outlaw receiver and the Onkyo DV-S535 DVD player with the Marantz SR-7000 receiver, which has a 96-kilohertz digital-to-analog converter, and the Pioneer DV-C503 multichanger, which outputs a 96-kHz PCM signal. With this setup, I could play some of Classic Records' digital audio discs, which achieve 24/96 resolution under the DVD-Video format and were developed as a delicious preview of high-resolution audio while the DVD-Audio format was being sorted out. The sub took Somethin' Else, the Miles Davis session released under Cannonball Adderley's name, without flinching. On "One for Daddy-O," in particular, Sam Jones' bass received the additional impact it deserved while retaining a sense of proportion with the other instruments.

In any setting, the AC Sub 100 filled in the midbass without diving too far, or too clumsily, into the lower regions. It never made a fool of itself, honking or squawking unnecessarily. It was a team player, always. To get this sort of versatility in a sub that lists for $350 is a rarity in home theater's budget division. If you've put together a system and lack only a subwoofer, it's time to jump in. With the AC Sub 100, that's feet first.

Highlights
• Sophisticated sound for a budget sub
• Killer feet