Added A Second Subwoofer To System

I haven't created a Virtual System yet so I will give a quick overview of my room and system.

I'm currently using a Classe CP-50 Preamp into Black Ice Audio Fusion 3502P power amp using the balanced in/out.

Speakers are Sonus Faber Lumina III's.

Subs are SVS SB2000 Pro and SVS SB1000 (not pro version)

Room is 13'L x12'W x 8' H

Subs went from both front corners of room to half way along both side walls.  

Listening position is approx. 7.5' from main speakers and 3' from rear wall.

I like the way the bass sounds with the subs in this position and although they appear close to my listening position, I can't hear or am aware of their locations.  

I set the phase for loudest output at these new locations.

My problem (?) is I feel that the overall volume of my system has dropped a bit.  I feel the need to turn the volume up a little louder than I did before the change.  

I'm actually concerned that I lost a little hearing overnight.  I am 63.  In all seriousness,  I doubt that I did although I know that hearing loss is inevitable.

Anyone experience anything similar? 


I have an SVS SB-3000 and one older SB-2000 in a theater (plus old 15" DefTech). I have my second SB-2000 in a 13x18x9ft TV room and it is more than enough for loud effects watching TV.   Those subs will do the trick in that room.

I will say that personally, I always use a test disc, sound meter and some testing work to fine tune the best in flat bass and room EQ. But this can be done by ear with a little analytical listening (not as fun).

Are you running your very nice Lumina IIIs full range?  I probably would and bet they go down into the 40s for sure. Setting sub phase for loudest is good, means the bass drivers are acting more in unison and not trying to cancel each other out.

I'd experiment with lowering the subs' low pass and turning up the sub volume of both. Not being able to tell where they are implies you do have the crossover set reasonably low already. I think the subs will overlap the SF speaker a bit if not kept low. I don't think the adjustment goes lower than 50Hz? 

After juggling subs around my primary audio system uses one R.E.L. Britannia B1 at 28Hz and an R.E.L. Storm III set at 30Hz, volumes maybe 40%? Works well for the ultra-low end in the 17x20x10ft room. Your two subs are nice for your space.

Good luck experimenting. Let us know what you hear.


Yes, I'm running my Lumina III's full range.  

My subs crossovers are set just below 60hz.

I'll try setting the subs lower and bringing up the volume as you suggested. 

Thanks for the response. 

What possibly happened is you smoothed out the bass so it is less prominent and more blended. It only sounds lower because it is smoother.

Not sure i can offer anything revelatory, but I’ve experienced variances in where I needed to set the volume knob to achieve pleasing spl and it was always due to room acoustics one way or the other.

I know my tracks and the volume where they sound right—historically.  After moving my seat and/or my speakers it’s apparent if something sounds louder or lower at that historic volume knob setting.  Aside from moving into or out of room nodes or null that could cause a volume change, a tonal change can lead to a perceived change in spl, I’ve always imagined.  We’re more sensitive to midrange, for example.  A bump or null in that region due to acoustics could affect our perception of volume.  

I added a sub only a couple of months ago and very much expect to add a second one later this year after I remodel my room.  I only played around with one spot before settling into the current placement so I’m out expert, but it’s tempting to suspect that corner placement would give a higher spl compared to mid-day sown the side walls?  I found my spot so quickly because my dealer gave me great guidance and I have an integrated amp with built in XO’s that makes sub optimization easy.  I cross at 50hz.  Subs play from 50 down and mains from there up.

I’d like to know if you think the tonal balance (aka, flatness of frequency) is better with subs out of the corners.  I recently improved my acoustics but didn’t move the sub, mans or my seat and it created what I call an imperviousness to volume.  I can crank it and it goes louder but the strain does not increase.  It refuses to lose composure.  But unlike what you are relaying, it is not like I’ve lost hearing and need to raise the volume.  It sounds great low but also loud.  I can enjoy it louder than before, I suspect, because I addressed some nasty pressure wave.  As I said earlier…it’s always acoustics.  And subs are as much acoustics derives addressing room pressure as they are “bass adding devices”. In fact, depending on the LF capability of ones mains, subs are much more the former than latter.

I’m trying to say that just because you can tolerate a higher volume setting or actually prefer it, doesn’t mean it’s not as loud.  Perhaps an annoying pressure (frequency) imbalance has been addressed.  Only you can assess that.  When we’re in a vehicle that feels like it’s going 50 when the dash says 85, we know that’s just our perception relative to how  85 feels in vehicles that are noisier and vibrates more.