Emotiva BasX S12 Ported 12″ Subwoofer Review

One of the best upgrades audio enthusiasts can make to a 2-channel or surround speaker system is to add one or more subwoofers. With proper integration, a sub like the Emotiva BasX S12 ($399) will extend and improve bass response, often dramatically.

The S12 is part of Emotiva’s BasX line of affordable high-fidelity audio equipment. This sub depends on a tried and true design—a 12″ driver in a ported cabinet—to deliver deep bass that you can feel.

This mini-review is the first of a series covering the individual components of an Emotiva BasX and Airmotiv 7.2-channel surround-sound system. The complete rig will be the subject of a forthcoming full-length review that references the mini-reviews of each component. For now, let’s take a look at the capabilities of the Emotiva BasX S12 subwoofer.


The BasX S12 is a rear-ported subwoofer that sports 300 watts of class-D amplification and a 12″ high-excursion driver. The substantial, internally braced cabinet measures 17.25″ (H) x 16.75″ (W) x 18.25″ (D) and weighs 48.5 pounds. Despite its affordability, this is no lightweight “toy” sub, it’s a serious piece of audio gear.

Emotiva BasX S12 Driver
Emotiva’s BasX S12 12″ driver. Photo from Emotiva.

Emotiva specifies a frequency response from 25 Hz to 150 Hz (+/-3 dB) for the S12, which is very good for a sub in this price range. It has rotary controls for crossover, phase, and volume adjustment. Plus it offers stereo line-level RCA inputs and outputs for use with 2-channel systems. It also features auto power on/off.

Setup and Performance

I reviewed two BasX S12s in my home theater. The system includes a Sony VPL-VW365ES 4K HDR projector paired with a Stewart Filmscreen StudioTek 130 G3 screen (120″ wide, 2.40:1 aspect ratio), Roku Ultra and Chromecast Audio streamers, Samsung UBD-M9500 UHD Blu-ray player, and the Emotiva sound system.

The 7.2 surround-sound rig contained the following gear: One BasX A700 7-channel amplifier ($599), one BasX MC-700 7.1 AV pre/pro with 4K and HDR pass-through ($599), two Airmotiv T1 tower speakers ($699/pair), one Airmotiv C1 center channel ($249), four Airmotiv E1 wall-mount surround speakers ($269/pair), and the two BasX S12 subs ($399).

Before I set the system up, I measured one of the S12s on my rooftop deck, perched atop a heavy-duty tripod. It’s not fully anechoic, but it does offer a better glimpse of what the driver is doing than in-room measurements.

Per my measurements, the -3 dB point of the S12 is exactly where Emotiva claims it to be, 25 Hz. I also found that bass response extends well above the specified 150 Hz; it does not roll off sharply until about 300 Hz. Here is a chart of close-mic measurements of the 12″ driver and the port, each taken from 2″ away.

Emotiva BasX S12 close-mic
The 12″ driver is the yellow plot, the port is the green plot.

Measured outdoors from a distance of 1 meter, I found that the S12 provides 105 dB of output from roughly 36 Hz up to 150 Hz (+/-2 dB). Measured indoors at the main listening position, room gain added considerably to the output at the lowest frequencies.

I relied on the MC-700’s built-in room correction to integrate the two S12 subs with the rest of the system. With EQ and room gain factored in, the pair provided clean, powerful, and smooth output that reached down to 24 Hz.

Playing deep test tones at high volume levels revealed that the sub’s output is largely limited by driver excursion at frequencies below 40 Hz. Hard as I tried, I could not trip up the amp. Emotiva specializes in amplification, and from what I heard and measured, it made sure the S12 has ample power to get the job done.

Inside the theater, the pair of BasX S12s sounded great. I enjoyed the 7.2 system’s precise yet lucid presentation. (Spoiler alert—the whole rig sounds great.) It speaks well of Emotiva’s engineering that the S12s are able to hang with the higher-end Airmotiv speakers and integrate seamlessly.

I’ll cover my listening impressions for movies and various music genres in the full 7.2 system review. But so far, I’ve enjoyed watching Life, the LEGO Batman Movie, Tron, and John Wick 2 on the system. I was amazed at how quickly I stopped thinking about the sound system, including the subs. I simply got lost in the experience, which is the primary goal of putting together a surround-sound system to begin with.

Music also fared well played through one S12 and the pair of Emotiva Airmotiv T1 towers included in the 7.2 system. The sub made it through the Tron: Legacy soundtrack—including the difficult “Disc Wars”—without missing a beat. Adding the second S12 to the mix expanded the system’s range. When blasting the likes of Datsik, Action Bronson, and Joey Bada$$, the punch and heft of dual S12s working in tandem made for an exciting and satisfying listening experience.


The BasX S12 is a fitting place to start exploring what the entry-level BasX line has to offer AV enthusiasts. It’s a no-nonsense performer that delivers exactly what you’d expect from a quality 12″ subwoofer, at a price that’s easy to swallow.

Emotiva’s BasX S12 deserves the consideration of anyone seeking a $399 sub that does justice to both movies and music. It’s a rock-solid performer from a company dedicated to making high-fidelity audio affordable.


BasX A700 amplifier ($599)

– 110 watts/channel RMS, 2 channels driven, 8 ohms and 80 watts/channel RMS, all channels driven, 8 ohms with less than 0.1% THD. – Frequency response is 20 Hz to 20 kHz (+/-0.07 dB) and this amp is 4-ohm compatible.

BasX MC-700 7.1 4K HDR AV pre/pro ($599)

– Support for Dolby Digital, Dolby TrueHD, Dolby Pro Logic IIx, DTS, DTS HD Master Audio, DTS Neo:6, and multi-channel PCM
– Six HDMI inputs (3 with HDMI 2.0a / HDCP 2.2 / HDR10 support)
– Two HDMI outputs (1 with HDMI 2.0a / HDCP 2.2 / HDR10 support)
– One set of 7.1 channel unbalanced audio main outputs
– Balanced and unbalanced subwoofer output
– Bass management, auto-EQ, and manual EQ
– Built-in headphone amp

(2X) Airmotiv T1 tower speakers ($699/pair)

– 3-way tower with dual 6″ woofers, 5.25″ midrange, folded-ribbon tweeter
– 4 ohm impedance with 88 dB (2.83V/1m) sensitivity
– 150W continuous / 300W peak power handling
– 37 Hz – 28 kHz (+/-3 dB) frequency response
– Supports bi-amplification

Airmotiv C1 center channel ($249)

– 3-way center with dual 5.25″ woofers, 3″ midrange, folded-ribbon tweeter
– 4 ohm impedance with 89 dB (2.83V/1m) sensitivity
– 120W continuous / 250W peak power handling
– 50 Hz – 28 kHz (+/-3 dB) frequency response
– Supports bi-amplification

(4X) Airmotiv E1 wall-mount surround speakers ($269/pair)

– Low profile, only 4″ deep
– 2 way surround speaker with 4″ mid/woofer and folded-ribbon tweeter
– 8 ohm impedance with 85 dB (2.83V/1m) sensitivity
– 60W continuous / 120W peak power handling
– 65 Hz – 28 kHz (+/-3 dB) frequency response

Sony VPL-VW365ES 4K HDR projector ($7999)

Roku Ultra 4K/UHD HDR media player/streamer ($109)

Chromecast Audio media player/streamer ($35)

Samsung UBD-M9500 Ultra HD Blu-ray Player ($399)