Gain level on a REL sub

@wolf_garcia BASS not base.

I make that mistake often and I'm a Double Bassist.

@labpro Then add in your 1 REL using the crawl method. Very small movements of the REL can make a big difference.

The subwoofer crawl is accomplished by positioning the subwoofer (not a sub-bass speakers) stationary at the listening position. The user then moves around the room noting and marking the strongest or best low frequency locations for subwoofer positioning.

Originally from Richard Edmund Lord and more recently from a REL brochure:

 [["REL subwoofers (I still like our original term Sub Bass System for its more complete description of what we do)"]] 

+1 on the Rythmik F12G.  I have one (one) myself and it's a great sub for music.  I have a dual system connected to it (home theater plus a 2.1 music system) and it excels in both applications.  I have no problem getting superbly musical, tight bass from it.  It's highly adjustable to that end (but does not have a DSP app associated with it - you'll have to do it manually) and digs deep.  Can't recommend this particular sub enough.

I would have been very interested in trying a Rythmik, but for those who don’t know this, the Rythmiks using the plate amps with high level connections (I think they’re the PEQ3s?) cannot be used on amps that have differential, or floating, outputs. Amps will go boom. In systems like this the Rythmiks must use the line level inputs.

Bass is both an instrument and a fish.

We are really talking about two different speakers here.  I had the same Hsu sub and yes, it was a beast, providing very deep bass with slam factor.  But, after messing around with it for a year I ended up realizing that I just did not like it.  The only way to get rid of the port chuffing was to bung up both ports.  Even then it was just too slow for my Snell D's and certainly for my LRS.  I never tried it in a home theater setup and I imagine it would be great for that. 

Enter the REL T9x and it was a whole different ballgame.  For me, the REL is much more nuanced and punchy, quick and 'musical'.  I will be putting another one in my system at some point in the future.  Or maybe try a different sub for flavor - Rhythmik perhaps?  But, not a Hsu.   

Anyway, I can totally see where you are coming form OP.  The REL will not do what the Hsu did.  Not in a million years.  But, I will say that I never turn the gain up on my T9x more than 5-6 clicks.  Even in my long 40 x 15 basement the T9x gives me more than enough.