Rythmik vs JL vs REL

I recommend the Rythmik,

I'm not familiar with the other two brands, but I have dual Rythmic sealed 15 EHP subs with an Anthem mrx720. I cant imagine anything better. Music and movies both are great. They do everything they are asked of them.

I do have a mini dspHD but you may not need it. 
Good luck.

I have Rythmik 12 and 15. The 15 plays cleanly right off the lower end of the chart. It is very musical and not just a thump machine like the 12" Rythmik subs, IMO.

I would suggest the Rel T7i for a room that small. It sounds fantastic, and would not overpower things in that room. It does not have room correction, but sounded better to me than more expensive subs I tried that had room correction. I think I saw a used one on Audiogon for $695. 

In the frequency range it covers, the ULS does a fantastic job, it just doesn’t cover as much of the frequency range as I would like, especially in the EQ2 mode, for a little bit more the Rythmik F12 does a better job. The ULS srill beats most other sealed subs around its price.

@mzkmxcv 

So you don't like the  ULS-15 MK2?

The HSU subs, except their sealed, is really good. The HSU VTF-2 MK5 for instance is the best sub out their at its price range. 
 
Rythmik and Rythmik are my go to.

So I don’t need the room correction as the anthem already has it. Also does anyone like Hsu Research subs? For the price I could get 2 of them!

"...might also consider SVS's new sb-3000"

+yes to considering new SVS SB-3000

I'm also trying to decide between sub brands, and am shopping dual units as upgrade from single REL R-328 which to my listening has sounded great over past 5 years.

But I got this hypothesis that for the results & performance, REL is overpriced relative to other brands.  I'm still considering them in my short list, though:

• SVS SB-3000 x2 ($1899 total)
  
• Rythmik F12 x2 ($1786)
  
• Rythmik F12-300 x2 ($1400)
  
• REL S/3 x2 (used, $2400 + $100 ship)
  
• REL S/3 x1 (used, $1200 + $100 ship) + existing R-328 <= yes it can be done, got very helpful & detailed how-to instructions from John Hunter, REL owner & lead designer
  

I might also consider SVS's new sb-3000. Lots of room correction built into the control app. You can download it for free and check out the settings. I'm currently deciding between the sb-3000 and a rythmik f12.