Subwoofer Reviews

BOTTOM LINE

The CSX-12 Mark II is the first $400 sub I’ve heard that gave me the “thrill ride” effect I like to experience when I watch action movies. It gives home theater fanatics that gut punch they crave, and it gives audiophiles the definition and precision they want. The only thing it lacks is ?30 Hz power, but you’ll need something a lot bigger and/or a lot more expensive to get that.

MEASUREMENTS

Frequency response

34 to 154 Hz:  ±3 dB

Bass output, subwoofer (CEA-2010 standard)

• Ultra-low bass (20-31.5 Hz) average: 103.2 dB

• Low bass (40-63 Hz) average: 121.5 dB

The frequency response measurement seen in the chart is with the CSX-12 Mark II’s crossover bypassed. I measured the subwoofer with a Clio FW analyzer in stepped sine mode using ground plane technique, with the sub on the ground and the microphone 2 meters from the front of the sub, and the measurement smoothed to 1/12th of an octave. The measurement doesn’t show a lot of response below 35 Hz or so, and Cadence rates the response down to 25 Hz, so I checked it by using the MLS mode on the Clio, and then by close-miking the woofer and slot port and summing their responses. The 34 Hz result quoted here is the best I was able to get. Combined low-pass function of the driver, box, and crossover is -18 dB/octave with the crossover engaged.

I measured bass output using the CEA-2010 method. Bass output is massive in the second octave, especially that 63 Hz figure. This is more like what I expect to measure with a big 15-inch sub. Output stays pretty solid all the way down to 25 Hz, but below that it dives, putting out just 91.3 dB at 20 Hz.

And that bass boost control? At 50 Hz — the frequency at which the manual says it operates — there’s a 12.4 dB difference between the 0 setting and the +12 setting, so it’s a boost control, not a boost/cut control. (Although I guess you could consider it a +/-6 dB boost/cut control.) The utility of this control is limited, though, because its bandwidth is so broad that it has a large effect on the entire bass spectrum. For example, at the +12 dB maximum setting, it boosts +6.7 dB at 80 Hz and +9.0 dB at 30 Hz. In my opinion, this control should be redesigned so that it delivers a narrower, higher-Q boost at 50 Hz. As it is, it’s barely more than a second volume control. —B.B.