From that list it appears Rythmic wins the race?
Or is there more to it then just numbers?
My room is basically 16x16x9
I've posted my HT build on here.
http://forums.audioholics.com/forums/pros-joes-systems-gallery/74678-my-klipsch-reference-series-home-theater-build.html
There is indeed more to it than just peak output numbers.
Those CEA2010 numbers basically say, how loud can you blast a tone at a certain frequency for a very short amount of time with less than a certain amount of total harmonic distortion. That THD number is meant to be "inaudible" although the limits are somewhat debatable.
So distortion is one factor. For example, the Rythmik FV15HP can produce higher output at frequencies above 20Hz vs. the SVS PB13-Ultra, but the FV15HP is doing so with higher distortion than the PB13-Ultra (which stays ridiculously low in distortion). Now, the FV15HP's results are still a passing THD result under CEA2010 specs, so that higher distortion is still said to be inaudible. But it's right up against the distortion limits, whereas the PB13-Ultra's distortion figures are way below the limit. Never-the-less, you supposedly won't hear the higher distortion - we do suck pretty bad at hearing bass as humans
There's a lot more than just peak output though. There is sustained output, which is much more difficult to produce since the voice coil heats up big time and doesn't have a gap in the sound to cool down. There is linear power response, which looks at whether the frequency response has the same shape regardless of how loud things are being played. For example, a sub might have a nice, flat frequency response graph when it is playing at 90dB, but if you turn the volume up to 100dB, you might see it play flat down to 30Hz and then slope downward so that the output at 20Hz is still only 90dB. This is a very common circumstance where a sub basically runs out of output capability at certain frequencies at a certain point and never gets any louder, even while higher frequencies continue to get louder as you turn up the volume. And there is transient response, which is how quickly the sound of the sub starts or stops when the signal tells it to. This is a big deal. This is what makes a sub sound "tight" or "flabby" (in addition to room interaction, which also plays a huge role in the sound).
Basically, when it comes to one sub sounding "better" than another, it's pretty much all about three things: extension, output and transient response. And all of those will be limited by distortion and power response.
SVSound's current lineup of subs get a lot of well-deserved praise because they produce a very flat frequency response right down to 20Hz. That response STAYS flat no matter how loud you turn up the volume. And the distortion stays low no matter how loud you turn up the volume. They do have their output limits, of course. But if you turn the volume up beyond what the SVS sub can play, it simply refuses to play any louder - there is no additional distortion, distress or any risk to the safety of the driver and no degradation to the sound quality. Transient response is tight due to high quality drivers and rock solid control over those drivers by the amps. So they're just good subs all around, but you do pay a little bit of a premium for that performance.
Rythmik's subs are very similar. Rythmik allows their subs to become a little bit less linear in their frequency response when you crank the volume to maximum levels. If they limited the FV15HP so that it remains very linear all the way down to 20Hz no matter how loud you crank it, they would essentially be limiting the max output to the max output of the sub at 20Hz alone, which is a bit lower than something like the PB13-Ultra. But instead, Rythmik allows the FV15HP to keep playing louder at frequencies above 20Hz. So if you crankt the volume up to its maximum, the frequency response is no longer perfectly flat and linear. It's curved now and slopes downward towards 20Hz. But that's a perfectly fine design choice! It means that in the bass region where most of the bass in music is found (around 40Hz and higher), the FV15HP is capable of more output and headroom.
So if you compare the FV15HP and the PB13-Ultra, the PB13-Ultra has a tiny bit more extension (just barely), the PB13-Ultra also has more linear power response - keeping the frequency response very flat no matter how loud you crank it. The FV15HP though is capable of more output at all the frequencies above 25Hz. The power response isn't as linear and the distortion is higher. But the distortion is still inaudible supposedly (although it's right up against the limits of audibility).
Both have tight transient response thanks to high quality drivers and excellent amps and well-built cabinets. And it's VERY important to note that these ultimately small differences only show up when you are cranking these subs to their maximum output capabilities. At more sane and normal output levels, great subs like the FV15HP and PB13-Ultra will sound almost completely identical.
With a sealed sub like the Epik Empire, at the really low frequencies, the drivers have to work much harder because they have no port to enhance their low frequency output. The Empire has more driver surface area, thanks to dual 15" drivers. Epik also employs an EQ boost of the lower frequencies that they incorporate into their amps. A natural sealed sub with no EQ boost will start to roll off and slope downward starting at around 40-50Hz and it will do so with a fairly gradual 12dB/octave slope. Epik employs their EQ boost so that the frequency response remains flat pretty much down to 20Hz and then they add a filter so that it slopes downward more steeply than 12dB/octave below that point. In essence, the response of Epik's subs looks more similar to a natural ported design thanks to their EQ and filters.
The thing is, the drivers alone are doing all of the work at those low frequencies, so distortion starts to rise and the limits of output way down below 30Hz are reached sooner than a ported design would allow. So you'll see that even though there are two 15" drivers and an EQ boost being employed, the Epik cannot play as loud way down at 20Hz as the ported FV15HP (which only uses one 15" driver) or the PB13-Ultra (which uses only one 13.5" driver). And thanks to the PB13-Ultra having more amplifier power and an extremely capable driver, it can actually output louder sound at 20Hz, than either of the FV15HP or Empire, even though it has the smallest driver.
Everything's a matter of design choices and hitting price points. So you've got to decide what you're really after and more important than that, realize that the room is a full 50% of your sound system. And the room has a tremendous impact on the bass that you hear. Bass waves bounce around a room like crazy - crashing into eachother and creating all kinds of cancellations and double ups that completely alter the sound of a subwoofer in that room vs. the sound of that subwoofer out in an open field, or the sound of that subwoofer in any other room!
Starting with a subwoofer that is very linear at all output levels is often a good thing because then you know that any change away from linear is due entirely to the room and not the sub itself. It makes it relatively easy to EQ the sub for that room because - being a linear sub - you know how it will react to being EQ'd. But it isn't necessary to have a linear sub in order to get linear response! A room's acoustics will boost the lowest bass frequencies and add peaks and dips in the higher bass frequencies. A sub that slopes downward in the deepest bass might end up being very flat and linear in a room thanks to "room gain" and the way the room boosts the lowest bass. So it often turns out that a sub that is very linear and flat all on its own requires a fair bit of EQ to make it flat and linear in a room! While a sub that has a downward sloping response all on its own actually has a flatter response in a room without any EQ applied at all!
