JL Audio e112 or HSU ULS MK2

I can’t speak for the HSU ($860 shipped), but I can tell you how the Rythmik F18 ($1530 shipped) compares. Keep in mind that the E112 is $1900 (not sure if including shipping).

The F18 gets louder throughout the entire passband. The F18 maxes out at 103.2dB at 20Hz and the E112 maxes out at 97.5dB, with 50Hz maxing out at 116.1dB and 114.7dB respectively. Remember that +3dB is a doubling of wattage, so the E112 would need almost 4x the wattage to get as loud at 20Hz. So, the Rythmik for sure wins in the headroom department. Keep in mind that room correction or DSP should be used with subwoofers, especially if not going dual.

Having clean bass means low distortion. The E112 stays below 5% THD from 30Hz up at 100dB. The Rythmik obtains the same feat at 110dB. The Rythmik stays below 5% THD from 32Hz up at 115dB, the E112 fails noticeably at even 110dB.

To have tight bass mainly means staying below 1 group delay cycle. Both easily do this; however, the impulse response of the F18 is better.

So, this all shows that the Rythmik F18 is much better than the E112 in basically every perceivable way, and for almost $400 cheaper.

Rythmik and HSU are very competitively priced for the given performance. So, I would say the HSU ULS-15 would perform near identical to the E112, at less than 1/2 the price.

@mzkmcxv 
Thank you for your feedback. At this time I am not interested in an 18" subwoofer. It is either going to be JL or HSU.

@danimaz, the 18" model is Rythmik's newest (available in both sealed and ported versions), but 8", 12", and 15" models are also available, the 8 and 12 priced at less than a grand, the 15 just over. All feature owner/designer Brian Ding's custom designed aluminum-coned woofers and patented Direct Servo-Feedback plate amps. Ignore them at your own loss!

@bdp24: Why do you prefer Rythmik over HSU or JL? Do you own one?  

I'll research more about Rythmiks but the thing is there are thousands of subwoofer manufacturers with their own custom technology and methodologies. The reason I chose JL & HSU was because I've heard the JLs and they sound really really good to me and while I was searching for JLs I came across HSU. HSU seem to get a lot of positive feedback from their owners. The biggest negative about HSU is there are no resellers that is why I want to attend AXOPA in Chicago and check it out. 

I don't think Rythmik will be there...

@danimaz: Rythmik is about just as popular as HSU, they are very competitive. Rythmik is partnered with Ascend Acoustics, and Salk not only uses them in some of their towers, but they also take Rythmik’s kits and improve on it with thicker cabinet/better bracing and also custom finish (at a premium of course).  
  
As I showed, the F18 is undoubtly a better subwoofer than the E112, for less, so a cheaper one like their sealed 15” or HSU’s sealed 15” should perform near identical. Also as stated, dual of either would absolutely destroy the E112, and you can go dual HSU for $2100 via the bundle.