Old and New-- adding Rel s510 or 812 Sub to heritage (older) McIntosh system-- Worth it?

Appreciate advise on adding a subwoofer to my older McIntosh system.  That system  consists of a 2125 Amp, C28 pre amp, Mc101 Equalizer, XR5 Mac speakers, and a Bluesound Node X (new) for streaming from Tidal (jazz, classical, blues, some folk).  Room is 21 x 15 x 8.5.

I'd appreciate advice on two fronts:  will the Rel subs (S510 or S812) significantly add to the depth and spacial experience of the sound?  Not interested in bass boom, but increasing the spacial sense and lower bass definition of sound (which seems to be Rel's wheelhouse).  And secondly if so, would a single S510 be sufficient in my room size or should I look for a single S812.  Don't want dual subs at this point.

Just one thing to add-- in my 40 plus years of moving this system to various homes and rooms, this is the first time (since my old direct disk phonograph days) that the system has come alive, primarily due to the moving of the speakers away from the walls, and having a room which really sounds good.  The magic of two channel audio is so nice, with disappearing speakers and the experience of live sound (especially with acoustic perfomances)  I've auditioned much higher end systems in dealer showrooms which I did not feel carried the warmth and realism that I now experience.  The final piece would be to get a bit deeper and richer soundstage which many reviewers report from a properly set up subwoofer.  Thanks in advance.   


It sounds like you really like the magic that you are now enjoying. Don’t ruin it adding a subwoofer. You might be taking one step back!

Borrow a Sub and see if you like it.  I have two REL S/812 and they add a lot to my system.  Let your ears guide you, not what anyone else thinks you should do.  Cheers.

Thank you yogiboy and bigtwin-- I agree with you both in the sense that I will only buy a Rel unit that I can listen to and then return if unsatisfied.  Your comments are very helpful in that regard.  I certainly don't want to "mess up" a good thing, but I have read some really good things about Rels for two channel audio, as you mention bigtwin.  Currently trying to decide from buying new from Rel, or a "scratch and dent" from a dealer.  Both are returnable up to 60 days.  I have to add the people at Rel have been really first class in answering questions.  Thanks again.

Forty plus what? Ten? Fifteen?

Be good to your back. Get the small wooden $12 dolly from Harbor Freight, a 20'-30' RCA cable from Blue Jeans cable and a ground lift plug. Decoupling with the dolly may be a second surprising improvement.

In your reading any opinion that lacks a direct in room comparison of another brand its relatively worthless. A direct comparison with the -6dB "Sub-Bass System" your considering and a -3dB EQ equipped Subwoofer would provide you a valuable understanding. Afterwords you can return both of them.

Since this community is decades behind pro audio integration of low frequency you might want to use a number of manufacturers who offer home trial before committing to a used unit. yogiboy's advise could easily kick in 'all over again.'

All the best with your search.