The super-deep yet somewhat melodic synth bass line in Olive's "Falling" confirmed my choice. It sounds good in Max Output mode, but I always got the feeling I was listening to a subwoofer. In Max Extension mode, the system sounded more like an ideally set up pair of very large tower speakers. In this mode, the system simply rendered every bass note cleanly and evenly without distortion, instead of adding extra punch and unnatural dynamics -- something subwoofers often do, which is one reason many audiophiles shy away from them.
Of course, no subwoofer evaluation would be complete without an audition of the Saint-Säens "Organ Symphony" -- the famous recording from the Boston Audio Society Test CD, with pipe organ notes that drop down to 16 Hz. The Ultra-X12 had no problem reproducing the deep notes in either mode, but the response seemed smoother and more consistent from note to note in the Max Extension model. I found that, in either mode, the Ultra-X12 could easily shake my projector image during the lowest notes.
Here are the measurements for the Outlaw Ultra-X12 subwoofer. Click on the photo to view the chart in a larger window.
Max Extension: ±3.0 dB from 19 to 179 Hz
Max Output: ±3.0 dB from 21 to 173 Hz
Crossover low-pass roll-off
Maximum output (Max Output mode)
(1M peak) (2M RMS)
40-63 Hz avg 120.7 dB 111.7 dB
63 Hz 122.3 dB L 113.3 dB L
50 Hz 121.4 dB L 112.4 dB L
40 Hz 117.8 dB L 108.8 dB L
20-31.5 Hz avg 113.7 dB 104.7 dB
31.5 Hz 116.1 dB L 107.1 dB L
25 Hz 115.0 dB L 106.0 dB L
20 Hz 108.3 dB 99.3 dB
Maximum output (Max Extension mode)
(1M peak) (2M RMS)
40-63 Hz avg 119.2 dB 111.2 dB
63 Hz 120.8 dB L 111.8 dB L
50 Hz 120.2 dB L 111.2 dB L
40 Hz 115.8 dB L 106.8 dB L
20-31.5 Hz avg 111.4 dB 102.4 dB
31.5 Hz 112.9 dB 103.9 dB
25 Hz 111.5 dB 102.5 dB
20 Hz 109.3 dB 100.3 dB
The chart here shows the frequency response of the Ultra-X12 in Max Extension (blue trace) and Max Output (green trace) modes. The response is for the most part flat, with a broad but very mild rise between 60 and 130 Hz.
The CEA-2010A results for the Ultra-X12 are fairly similar to those of the closest competitor I've measured, the SVS PB-2000. In the low bass (40-63 Hz) region, the Ultra-X12 in Max Output mode has a +1dB edge, delivering 120.7 dB average output vs. 119.7 for the PB-2000. In the ultra low bass (20-31.5 Hz) range, the Ultra-X12 puts out -2.6 dB less than the PB-2000, achieving 113.7 dB average output vs. 116.3 dB for the PB-2000.
Here's how I did the measurements. I measured frequency response using an Audiomatica Clio FW 10 audio analyzer with the MIC-01 measurement microphone. I close-miked the woofer and ports; summed and scaled the port responses; then summed the combined port responses with the woofer response. Results were smoothed to 1/12th octave.
I did CEA-2010A measurements using an Earthworks M30 measurement microphone, an M-Audio Mobile Pre USB interface, and the CEA-2010 measurement software running on the Wavemetric Igor Pro scientific software package. I took these measurements at two meters peak output, then scaled them up to one-meter equivalent per CEA-2010A reporting requirements. The two sets of measurements I have presented here (CEA-2010A and traditional method) are functionally identical, but the traditional measurement employed by most audio websites and many manufacturers reports results at two-meter RMS equivalent, which is -9 dB lower than CEA-2010A. An L next to the result indicates that the output was dictated by the subwoofer's internal circuitry (i.e., limiter) and not by exceeding the CEA-2010A distortion thresholds. Averages are calculated in pascals.
I can't conjure a complaint worth noting about the Ultra-X12's sound, especially considering its affordable price. It'd be nice if there were some way you could switch between Max Output and Max Extension modes remotely -- especially if you're planning to install the Ultra-X12 in a cabinet or behind a fabric wall -- but I can't imagine how that might work, considering you have to physically insert or remove a foam plug to change modes.
Although the Ultra-X12 can shake the floor, it doesn't have the raw air-moving power of larger 15-inch models, or 12- or 13-inchers with more powerful amps and bigger enclosures. But all of those subs, to my knowledge, are larger and more expensive.
Comparison and Competition
To get a better handle on the Ultra-X12's performance, I compared it with my reference sub, an Hsu Research VTF-15H that costs $879 (plus $139 shipping, and soon to be replaced by the VTF-15H MK2). I used the Hsu in EQ2 mode with one port plugged, which gave me a sound roughly similar to that of the Ultra-X12 in Max Output mode.
The 15-inch driver and the much larger enclosure of the Hsu enabled it to shake my listening chair almost as if the driver were physically connected to it; it delivered a visceral experience that the smaller Ultra-X12 couldn't match, even though the Ultra-X12's maximum output measurements (see below) come pretty close to the Hsu's. I liked the way the Ultra-X12 really dug into electric bass lines, though, and the Ultra-X12 seemed to blend better with the MartinLogan Motion 60XTs, especially with the sub in Max Extension mode.
In terms of competition, the closest model in the SVS line is the 12-inch, $799 PB-2000. It's a great sub, with a few dB more output than the Ultra-X12 in the ultra low bass (20 - 31.5 Hz) range, but it doesn't offer different sound modes like the Ultra-X12 does. The closest model in the Hsu line is the $639 VTF-3 MK4, a 12-inch model with sound modes similar to the Ultra-X12's. Unfortunately, I haven't tested it, so I can't say anything about it. Axiom's EP175 v4 is a bit more expensive at $685 and has a smaller, 10-inch driver.
There are many outstanding, affordable subwoofers available today. Many of them perform very similarly and look practically indistinguishable. It seems to me that it's not a matter of choosing the best subwoofer, it's a matter of choosing the best for your budget, tastes, and application. So where does the Ultra-12X fit in? It's for two types of enthusiasts: 1) those who want true high-performance subwoofing but want to keep their investment to a minimum; and 2) those who want smooth bass response across several listening positions (i.e., for multiple listeners) and who thus plan to use two smaller subs instead of one larger one.
• Outlaw Audio OSB-1 Powered Soundbar Reviewed at HomeTheaterReview.com.
• Outlaw Audio Debuts Model 975 AV Surround Processor at HomeTheaterReview.com.
• Check out our Subwoofer category for similar reviews.