[QUOTE=beastaudio;38434841]The answer to this^^^^^^^ is THS VVVVVVVV
This is silly. I venture a guess that 90% of the guys unhappy with their midbass either haven't spent the time properly integrating their systems, or if so, haven't given a little bump to their "Midbass" area. Bump 60hz all day long. That ain't midbass. 4 s2's......aka EIGHT sealed 18's are capable enough to get you all the punch you might need in a domestic space. Guys that professionally calibrate stuff are sitting back laughing at this right now. 215's, 4s2's, and just for fun, a pair of OS pro's or growlers? That's so overkill it's not even funny, and you guys know what I run. You can't be calling out fools for spending $4,000 on audio interconnects and speaker wire if you too are just pissing the same amount away on more subs that won't do anything to your systems if not calibrated to the rest of the system properly...
Beast, I agree with the need to properly align and set up the subs with the mains, paying special attention to the xo region. Then dialing in a FR curve to ones tastes. This is why I think the 215 is a good choice for many who don't want to spend the time measuring and tweaking or don't get good results from an auto eq system.
As far as overkill, that really comes down to listening habits and the room environnment. We were enjoying the Eagles blu ray the other day at +15dB with a +15dB house curve slowly rising from 150hz to 35hz. That is 135dB at 40hz @ the MLP! Do think this can be accomplished with the 215's? I know in my room it will not, don't even need to measure 215's in my room to figure that one out. 215's are "only" 95dB sensitive and handle 2000 watts. They will give up 6dB to the 212HTR's all the way down to 80hz. I think in my room the 215 would be capable of about +5dB with this house curve at this listening distance (125dB max). Still good, but not what I am looking for.
The biggest problem I see with large SPL subs is it generally takes more time and care to get the most out of them. IMHO REW or other measurment software is a must in large sub set ups.