Originally Posted by tamiya
PSA V3611=1920W RMS, 18"x2, cone area 509
XTZ 3 x 12=1500W RMS, 12"x3, cone area 340
JTR 1400 =1400W RMS, 18"x1, cone area 254.5
If their outputs are similar to each other, same ported design too, what's the cause? amp power? cabinet sizes?
BTW, judging from the number on the paper, it looks like 1400 is most efficient design?
There are too many variables to boil it down to just cone area. Even if you add in amplifier power and cabinet volume, we still don't have a complete picture. For instance, there are motor strength, excursion (how much the cone moves in and out), port design and port tune, and DSP to consider. All of those factors interrelate according to a designer's philosophy and his specific implementation. And, the choices he makes affect both the performance and the price of the subwoofer.
I don't begin to understand the interrelation of all of those factors, and even someone who really does (such as a subwoofer designer) could probably spend most of a day trying to explain them all to us. And, we might not fully understand the explanation. In the end, designers make certain choices and trade-offs in their designs.
For instance, the PSA subs, such as the V3611 will have more mid-bass (40Hz and up) SPL than the other two. It will have quite a bit more, in fact--perhaps the equivalent of two Cap 1400's or 3X12's. But, below 30Hz, and especially below 20Hz, it will lose SPL much faster than the other two will. At very low-frequencies, it might take two V3611's to equal one of the other two subs.
In all cases, the designer is making choices to emphasize certain frequencies with more SPL. And, there is no one-size fits all solution. People who have PSA subs are very happy with them, and from my experience, tend to stay very loyal to the brand. But, I have noticed that the emphasis on more mid-bass SPL may make PSA owners more likely to upgrade or add subwoofers to obtain even more low-frequency SPL. They stay within the PSA line, but they move up from 15" models, to 1811's, and from 1811's to 3611's.
By contrast, fewer JTR owners seem to want to upgrade from Cap 118's or Cap 1400's to even more powerful (and expensive) models because they are already getting a lot of low-bass SPL. (Note: JTR doesn't offer an upgrade path, but there seems to be little need for one.)
So, everyone just needs to decide for himself what he is looking for. Someone who is looking to have 120-125db db from about 40Hz up, will probably enjoy the V3611 more. And, some people really do like to listen at very high volume levels. Someone who is content to top out at about 115-120db in that same frequency range, but who wants to maximize the <20Hz frequencies with more SPL, will probably do better with the ported Captivators or the XTZ 3X12. Since, ~120db is roughly Reference (although some allowance must be made for distance from the sub to the MLP) that is still pretty loud.
As a general rule, we pay extra for frequencies below 20Hz, compared to frequencies above 20Hz, as it takes more effort to produce them at high sound pressure levels. But, that is just a generalization. This truly is a YMMV question, and one which each individual ultimately has to answer for himself. I hope that this helps a little!