Mass-loading subwoofer

You have a $5500 subwoofer.

No need to reengineer it. Get another one if you're curious about improving overall performance of your setup as a whole.

Improve the room acoustics.

The best way to combat resonance in a subwoofer enclosure is with internal bracing. But that the job of the designer/builder. The consumer cannot add internal  bracing, as the braces eat up some of the enclosure's internal volume, which affects the sub's performance characteristics.

For a view of great internal bracing, head over the website of Salk Sound. Jim installs the Rythmik servo-feedback subwoofer system in enclosures of his own design and build, and his bracing is the best I've ever seen. Check out the illustration of the interior of the Salk/Rythmik 12 sub!

Thanks for the responses folks! 
 

I DO realize that Rel themselves dissuade against using a platform but with my current flooring it does seem to work better. 

Yes, it IS an expensive subwoofer but I paid less for it (used) than most other midline or even less brands would’ve cost. I have zero intention of changing subwoofers but merely wanting to experiment using others expertise as a starting point.
You are very correct about room acoustics though and would certainly appreciate any suggestions in that department. 

I sincerely hope that this response doesn’t come off as overly negative though and I’m merely asking for advice within the confines of my situation. 
 

Thanks so much! 

I have a 42 pound curling stone on my REL 7i. Not sure it makes any difference, but it looks good. 

… actually, I do think that it’s always good to get a completely different perspective from the way you are currently thinking so maybe I really shouldn’t limit advice at all. 
 

Thanks again! 

Ha ha! zlone that’s a unique idea but where would I go about buying that? 
 

What is everyone’s thoughts on the “bundled” flooring idea? If I remember correctly, a 50# bundle was about $60-70. The bags of steel shot were pretty reasonable too. 

For years I have been going to countertop granite and quartz 

and have remnants cut to size it’s 1-1/4 inches thick and many beautiful colors of nature even 7nder my dacs I use a bit of blutac at the corners 

even on some Loudspeakers , looks great and a 16x15 cost me under $200

@zlone

You wouldn’t happen to have a picture? 😁

I have a 42 pound curling stone on my REL 7i. Not sure it makes any difference, but it looks good.

I just don't like the idea of either of those things. The concept is fine just use something that can't vibrate, or resonate. Maybe a rubber coated weight lifting plate. I think you can get one like 45kgs or more than one if you want. 

Some of the latest thinking is to isolate elements of the system from vibration and microphonics and there seems to be strong evidence for this. Consider looking into feet that isolate the subs from the floor rather than using feet that couple to the floor. This may accomplish what you are looking for in a different way.

Hmmm. Rubber-coated weights is an interesting idea too. 

The Auralex seems to already be pretty good at decoupling and especially for the price. An added benefit is that it’s much easier to move the subwoofer if needed. 
 

Something like Gaia’s would probably be better but also a good deal more expensive PLUS I really don’t want to have to remove the existing feet to replace? 

I was fighting with the set up of my sub and at the advice of some knowledgeable members here, I went completely against the REL guidelines. I moved the sub out of the corner (along the wall, approx 6ft. off the corner) and set it on a 1.5” thick granite slab…bingo. Problems solved. 

Jl1ny- Rel Special Carbon? That’s with a down-firing passive right? 
 

To be honest, I got the Auralex for my previous Rel (S5/SHO) which had the down-firing passive and it greatly improved it. I’ve never actually experimented without it with the G1 though. 
 

@curiousjim 

You wouldn’t happen to have a picture? 😁

I have a 42 pound curling stone on my REL 7i. Not sure it makes any difference, but it looks good.

Sorry for the slow response, I was traveling. I had hoped to post a picture on my return, using my PC to navigate the Byzantine image posting process on this forum. Being unwilling to set up a new account on an image hosting site for one picture and not having success with the copy/paste solution, I throw up my hands. 

@curiousjim 

You wouldn’t happen to have a picture? 😁

I had to set up a picture service for another post, so circling back on this request. 😀