Review: SVS SB13-Plus Subwoofer

I would never do what SVS did with its new subwoofer, the SB13-Plus. The company originally sent me a review sample last fall, but despite the fact that it sounded (and measured) great, SVS asked me to hold the review while its engineers tweaked the sub’s Sledge STA-1000D amplifier. It took months for the new amplifier to arrive. That’s months of revenue lost for the sake of slightly better sound. I can’t think of many companies that would have made the same decision, and frankly, I’d have approved the first version. Obviously, the guys at SVS have an uncommon passion for subwoofers.

What’s so special about this new amplifier? At 1,000 watts, it’s powerful — but so are lots of subwoofer amplifiers. The really exciting stuff is packed into a single knob and a small alphanumeric display. Push the knob and the display comes to life, giving you access to SVS’s Intelligent Function Controller, or IFC.

The first adjustment to come up is volume. Push the knob repeatedly to access high-pass and low-pass filters, which serve as a subwoofer crossover if your receiver or preamp doesn’t have that feature. Both are adjustable in third-octave steps from 31 to 125 Hz and can be set for –12 dB or –24 dB/octave operation. The signal at the SB13-Plus’s line outputs can also be delayed 0 to 10 milliseconds in 1-millisecond increments, in order to time-align the subwoofer with the main speakers. A phase adjustment provides more fine-tuning of the subwoofer/satellite blend. Audiophiles, whose two-channel preamps rarely have built-in subwoofer crossovers, should especially appreciate all of these features.

The sub’s room gain compensation feature tames the aggressive “bass bump” that can occur in smaller listening rooms. You can set it for 25, 31, or 40 Hz, and for –6 dB or –12 dB/octave low-frequency cut.

SVS saved the best feature for last: a two-band parametric equalizer (P-EQ). Each P-EQ can boost or cut bass in a band centered at a frequency you select. The idea is that you can eliminate your room’s worst bass resonances (or modes) and get a more even response. The SB13-Plus lets you choose among 13 center frequencies from 31 to 125 Hz; boost or cut in a range from +3 to –12 dB; and set the Q (or width) of the adjustment band from 2.0 to 14.4 (0.7 to 0.1 octaves). I’ve found that even one parametric EQ delivers a colossal performance improvement; having two will likely render your room’s bass modes inaudible.

The SB13-Plus has more going for it than digital bells and whistles. It’s built to the same robust standards as the company’s other subs. The beefy yet beautiful sealed-box cabinet contributes to the sub’s backbreaking 95-pound weight. The custom-designed driver has a cone made from a pulp/fiberglass composite with a fat rubber surround that looks like it was cut from a Segway tire. Audiophiles will appreciate the provision of XLR balanced inputs and outputs alongside the usual RCA jacks.

Although the SB13-Plus is chunky, it’s small when set beside most kick-ass subwoofers. That’s the idea. SVS presents the SB13-Plus as an option for spaces that can’t accommodate monsters like the 2010 Sound+Vision Editors’ Choice Award-winning PB12-Plus, which occupies more than twice as much space as the SB13-Plus. Finished in natural oak, my review sample was surprisingly attractive for a sub. It’s also available in gloss black, black oak, or cherry.