2 subs in a small room?


I recently added a REL T/5i sub to my system and have been very happy with the results.  Integration was a breeze and I am now more engaged in my music than ever.  So of course being a typical audiophile, I got to thinking if 1 sub sounds this good will 2 sound even better?  The challenge is my room.  Its very small at 9' w x 10' l x 9' h.  The back wall is about 3' high, above which it opens up to the rest of my house.  I have bass traps in this room.  Right now, using just 1 sub, my freq response from 20-1000hz is +- 2db with a -4db dip at 200hz and a +4db hump at 40hz.  Not perfect but my system still sounds amazing.

I know the general consensus is a second sub will sound better but I am concerned with the size of my room.  Will adding a second sub in such a small space over power it or will it actually help to smooth out nodes?


128x128tboooe
My subs are basically mirrored, to the outside of each speaker and behind almost touching the bass traps. The side walls slant upward to 10.5' high and lots of diffusion and absorption on all 4 sides. The sound is very good. I might experiment a little though after reading this thread.
I have 2 Rel G2's integrated with a pair of Sonus Faber stand mounts driven by a pair of McIntosh 601 mono blocks.  Tons of power for a treated 11'x 16' listening room.  The REL's are crossed over 55 and volume quite low at 8 to 10 on the REL volume setting.  Works extremely well....haven't heard many systems I'd trade it for. :)  Get a second REL.  Jim Smith in "Getting Better Sound" recommends 2 subs, even if inexpensive vs 1 higher priced one.  
My 2 cents.

perfectpathtech7 posts04-22-2016 3:08pm
I recently went from a single to stereo pair of subs, wanted to move more air, what I was not prepared for was the startling effect on midrange to high frequencies! More detail, wider stage, no joke it was jaw dropping. The explanation I found was there is a phase shift from summing 2 channels into one sub, or mono, masking information, had I known this years ago would have done a pair right from the start I second meerzistar’s advice!
Forgive perhaps the dumb question. I assume what you heard in the mids and highs are only present when the subs are playing low frequencies which is not all the time. So does that mean for parts of the music when there is no low freq information you do not have the improvement you described? Or is the improvement due to you crossing over your speakers at a higher freq?

I understand the idea the idea that multiple subs can help to smooth out modes but of course subs can only do this when they are outputting sound at and below the crossover point right? If the music I am listening to do not information at and below the cross over point throughout the song then will I hear differences in the mids and highs depending on if my subs are outputting sound?
ptrck8874 posts04-22-2016 7:15pmI have 2 Rel G2's integrated with a pair of Sonus Faber stand mounts driven by a pair of McIntosh 601 mono blocks.  Tons of power for a treated 11'x 16' listening room.  The REL's are crossed over 55 and volume quite low at 8 to 10 on the REL volume setting. 
Do you mind if I ask which Sonus Faber monitors you have?  I have the Evolutions and cross mine over at around 35hz.  At least in my room the Evolutions have a flat response down to about 40hz.  BTW, the G2s are crazy! 
Tbooe,

I find that there is usually a major improvement in the upper bass and much of the mid-range (say the two octaves below middle A and a fair bit of the octave above) when you get the subs integrated properly.  "Properly", in this case, includes smoothing frequency response thru the x-over point.  That smoothing can be done with more subs, EQ, or room correction (or any combo of the above).

I can't specify exactly why, but I'd speculate that it's probably a matter of cleaning up hash and overhang around/above the crossover point.  If not addressed, I believe it may have the impact of muddying response in the area described above.  Whatever the reason, the effect is usually very noticeable.  If you run Dirac, just a-b (single sub or a pair) with correction engaged and then off-line.  My guess is that you'll immediately understand what I'm talking about.