OK, so I'm looking at subwoofers now as I need a second one in my system to even out room modes for the new extra two rows of seating since upgrading from 6.1 to 11.1.6 and I've been thinking why not extend my bass lower while I'm at it. My current sub is fairly old and while some have told me it's "junk" I'm measuring a flat response in my room at least 22Hz at the MLP that started to fall off steeply below that, but with room correction on, it's now down only 4dB at 20Hz (I don't have any test tones below that currently). I don't play much pipe organ music and shaking the walls with notes I can't hear, well I don't know if it's worth it.
But assuming it is, I've been looking at my sub options and for all the rage about SVS subs, their frequency response graphs don't look that great to me. For example, with the SVS SB-2000 If it's showing 93dB in the response curve at 30Hz, it's like 87 dB at 20Hz (apparently -5dB is "fit in" with the +/-3dB by averaging in the middle instead of where it sits even at 30Hz and above, which is misleading in the numbers, but obvious in the graph) and 83dB at 15-16Hz or so (graph isn't easy to read precision). OK, so in other words, that sub is WORTHLESS at 16Hz. It can't put out the pressure wave to "feel" 16Hz and you can't hear it, so I'm not going to get anything out of that. Where's the improvement of this "modern" sub compared to my "ancient junk" from the mid to late '90s? It's down 4dB at 20Hz and only 1dB at 21Hz compared to 30Hz in my room.
How is that "junk" by "modern standards" ? I'm not seeing anything to make me believe that 12" "modern high excursion" sub with almost 3x the power amp rating is doing anything "significantly" different other than being slightly smaller and weighing slightly less. Is it "tighter" sounding? I have no idea without hearing it, but I do know "speed" is typically associated with higher frequencies and thus if you keep your sub out of the >80Hz range, it's not playing the notes that make it sound "slow". It sure as heck sounds good with my PSB speakers (similar to my Carver ribbons with 10" drivers). My PSBs are flat to 35Hz and with music in that range, they sound less loud but then I run the sub +6dB for more bass (hard to do that on the PSBs without EQ controls).
Now I'm using that example since that's supposedly the equivalent "modern" sub spec wise to my old 15" sub (bigger driver, less power that still shakes the walls at a fraction of the power it can run at with the dial at 1/3 in that room).
So I look at the SVS SB-Ultra 16 graph next ($2000 sub rated to 16Hz +/- 3db) that's supposed to be 'all that and a bag of chips' as they used to say. The 20Hz numbers look WAY better on the graph (down only about 2dB
@20Hz compared to 30Hz, say 92 instead of 94dB at that voltage input). BUT look at the 16Hz number (what I'd be interested in after paying $2000 for a subwoofer) and I'm seeing about 87dB. Well, that's down 5dB from 20Hz and 7dB from 30Hz. With a bit of fudging (half dB off in reading the graph which is not marked to 1dB), I guess you could call that +/- 3dB, but again it's misleading since it's really more like +0/-6dB based on the long term average from 30Hz-150Hz where it's pretty darn flat.
Is that sub going to rock my world with 32' pipe organ stops at 16Hz? It might do OK, certainly if I bought two of them, but at a cool $4000). That's a lot to get accurate pipe organ music (again, I don't know how much better explosions sound with big 16Hz support as opposed to 'just' 20Hz or even 24Hz.
So that brings me to SERVO subs. I'm looking at Rhythmic Audio's graphs and damn, I like what I see at 16Hz! The problem is that I know that the flat output only extends to a certain volume level and dies above that. What's hard to discern is what that volume level might be, exactly. In other words, I don't think I'm going to hit Dolby's 115dB peak level at 16Hz, probably nowhere near that level and that's the kind of data I need to make an informed decision. 85dB flat at 16Hz isn't going to rock my proposed pipe organ world. Is there some data somewhere on Rhythmic's absolute output capability (anechoic and perhaps a typical medium room sized average) based on frequency? Basically, I need to know what I'm dealing with so I know if I want to order one and how big I'd need to go for various performance parameters at "useful" levels. Given how difficult it is these days to preview multiple subs, I might have to go on data alone.
Overall, I just don't know if it's worth the expense to pursue 16Hz or if I should just be happy with 20Hz and work on evening out the room modes with a second sub like I originally planned. I suppose if the new sub really did sound better by itself than the old sub, I could give that one to my mother and get a second one, but then looking at SVS, two SB-3000s could be one SB-Ultra16 instead (and let's face it, I sit at the MLP most of the time so am I that worried about the occasional person the second and/or third row? I could throw the old Def Tech sub back there for room mode evening out for those two rows in most of the range and have the Ultra16 up front where it's going to do its thing for the MLP just fine (and even turn off the back sub if on one is back there if it's somehow muddying the sound of the front). I didn't really want to spend $2000 (I could get a new powered stretched screen and a 4K projector for not much more), but if 16Hz were going to really rock my world.... Would it? I don't want to shake the Conan replica sword off the wall either....
