RBH Sound I-12/e Sound Quality & Performance Tests

The majority of the listening tests done with the RBH I-12/e subwoofer was with music.  In the Audioholics Showcase family room system I compared it directly to two JL Audio e112's, which I know is an unfair comparison considering the 6X cost difference of JL subs and dual subs always being better than a single sub.  However, it was a good gauge to what I am familiar with in that room setup.

CD: Armin Van Buuren - Mirage
I fired up the title track "Mirage" to give the I-12/e a workout.  The room was pumping with deep tight bass.  As I cranked it up, the I-12/e held its composure well.  There was good weight to the bass, especially with 1 port plugged to increase the very low frequency output.  For comparative purposes I switched over to my dual JL Audio e112's.  There was really no comparison, the JL Audio's managed to muster up more tactile feel, and better overall quality of bass, which wasn't surprising given the cost difference and also comparing dual subs to a single sub.  However, I still respected what the RBH sub was able to do in my large room.  It provided very satisfying bass output for bass heavy music like this.  I never heard it strain or run into gross distortion, which was a testament to the well-engineered driver and limiter circuit in the amp.  Track #5 "I Don't Own You" had the 12" driver pumping really well in the RBH sub.  Thanks to the flat linear output above 80Hz, the sub blended in seamlessly with my satellite speakers allowing them to sound like a full range speaker instead of a sub/sat system. 

CD: Best of Fourplay
I like using this CD to test bass since some of the tracks really let you stress a woofer that simply can't handle a loud kickdrum.  Track #5 "The Chant" has been known to misalign a few voice coils in my theater room on wimpy designed woofers.  I cued this track up first and cranked up the volume.  The RBH I-12/e had no complaints.  It belted out clean tight bass without complaining.  I was particularly impressed with the seamless integration I was hearing between the sub and my satellite speakers.  I found a good blend to convince myself I was listening to a full range system instead of a sub/sat system.   Track #7 "Bali Run" showcased the wonderful bass playing of Nathan East.  It was a very satisfying experience to hear fulfilling bass round out the sound of my system at listening levels I'd be a bit embarrassed to admit I was enjoying in the comforts of my home while the wife and children were out. 

Blu-ray: Dark Knight Rises
Say what you want about Christian Bale, but in my book he was the best live action Batman to date. Dark Knight Rises doesn't disappoint when it comes to action, and especially sound. The opening scene with the giant plane pulling and ripping apart the passenger plane is pretty epic.  The I-12/e handled the deep bass without complaint. It may not have been as visceral an experience as my reference subs, but the end result was clean bass that gave plenty of heft to make you appreciate the scene.  I found the sub sounded cleanest with one port plugged which is what I'd recommend when listening to program material with very deep sustained bass.  My favorite bass moment in this film is when the Batwing takes off to flee the police force.  In my reference theater room the bass from my Status 8T's reference speakers (RBH's top model), makes your spinal column shake.  That is bass below audibility and very difficult to reproduce on all but the very best subwoofers properly set up in the room.  The I-12/e makes a valiant effort of recreating this effect and unless I hadn't experienced it on my reference system, I'd never know anything was missing.

There are 3 tuning modes for the I-12/e subwoofer as shown below in a screenshot from their manual.

RBH I-12/e System Tuning

Outdoor 2 meter ground plane testing of the RBH I-12e

The I-12e exhibited a very linear frequency response beyond 100Hz making it a good subwoofer for small satellite speakers requiring a higher than 80Hz crossover frequency.  The limiting factor for output of this sub above 20Hz was actually the amplifier, which wouldn't allow me to exceed 103dB output levels at 2 meter as seen above for continuous sweep tests.  I couldn't help wonder how much more output this sub would have if RBH chose an amplifier with a less aggressive limiter and how that would have ultimately affected my listening test results.

For max output, you will want to leave all 3 ports open.  However, if you want extended deep output and slightly more control below 20Hz, I'd recommend using 1 port plugged.  Trace #6 shows the woofer losing control below tuning with all ports open but plugging 1 port dampened and lowered this behavior to subsonic frequencies.

RBH I-12/e System Tuning

Tuning with all ports opened was around 21Hz but with 1 port plugged, it dropped to about 18Hz.  You do loose about 1-2dB of efficiency with one port plugged but in my opinion it's worth it for the increased extended low frequency response and better system control below tuning.  

CEA2010 Test Results

Here are the peak CEA2010 burst results taken at 1m and translated to 2 meter in the data table below.  The mic was SPL calibrated with a B&K 4230 reference microphone calibrator.

CEA 2010 Results 2 meter rms (measured sideways)

CEA Distortion Thresholds (2 Port Mode)

Based on the test results above, the I-12/e has earned our Large Bassaholics rating, signifying that it should be able to provide satisfying bass levels in rooms of 3,000 cubic feet to 5,000 cubic feet (read about our Bassaholics room rating system). If you can afford it, I would still go for multiple subwoofers, regardless of room size, for the sake of smoothing out the low-frequency response and extending dynamic range.