There are a couple of things. One is build quality, which they rate higher for the SVS (see the final score card). And also, about the Rythmik (
bold is added by me):
The Rythmik sub was unique in one way during the compression testing vs frequency. As you can see from the curve above, at the highest output level (the gray curve, as this sweep, 14 seconds long from 400 Hz to 10 Hz) triggered the sensor or compressor about the time we hit 80 Hz. As the signal continued to sweep lower, in a very short period of time, the compression released, allowing the signal to peak again right at about 60 Hz, and then before it got down to 50 Hz, the compressor becomes active again. This happens AGAIN at about 32 Hz, and as you can see as the sweep runs lower, the compressor releases and then returns several times in quick succession. Now it could be argued that music does not have any sweeping tones that range across more than a decade (400 to 40 Hz is one decade) and last 14 seconds in length. They would be quite correct. However, I cannot help but relate this to instances where I was listening to music and the output seemed to suddenly jump out as if the volume control was being rotated without any help from my fingers. I would suggest that the use of a longer hold time or integration time be considered based not so much on the signal sweep test shown above, but on my own sense that the sub seemed to go from too quiet, to just too loud all on its own frequently during its operation.
As we can clearly see from the curves above, frequency response is NOT independent of level, and if the system is pushed hard enough, it will roll off below 30 Hz, yet at lower power outputs, is certainly flat down to 20 Hz. (Red curve) at the bottom.
Rythmik FV15HP Subwoofer Measurements and Analysis | Audioholics
So there are reasons why the Rythmik may be regarded as inferior in some respects. That said, in brute output, by the measurements, it would appear to be superior.
I would pick the SVS, though I can certainly understand someone feeling differently about this. But to save money (and floor space), I would get the equivalent cylinder version, the
PC12-Plus. I like my SVS cylinder subwoofers, and am glad I do not have the heavier and harder to move box versions.
