I ran the numbers on the drivers they offer for diy and found the DS1200 wasn't all that far down from the DS1501.
They apparently used the DS1505 driver in the FV15 and they're currently using the DS1510 in the FV15HP, but unfortunately they don't have the ts specs listed on the site for anything other than the DS1501.
The DS1510 has 20mm of excursion rather than 15mm and can also handle 100 more watts, I suppose using the DS1501 as a template in Winisd and adding the extra excursion and power handling would be close, but it probably won't tell the whole story.
Below is the Maximum spl chart (factors in power handling, cone excursion, box size and tuning) of the DS1501 and the DS1200 with optimal tunings and box sizes of the LV12R and FV15HP.
300 watts to the DS1200 and 500 watts to the DS1501:
Below is the expected spl chart without any sort of eq. Notice I gave the DS1501 the 600 watts of the FV15HP to simulate (hopefully) the DS1510.
And finally the cone excursion charts. Using 2nd order high pass filters 2 hz below tuning on both subs to avoid over excursion. That puts the xmax/excursion of the DS1501 (15mm xmax) close to the 20mm xmax of the DS1510 used in the FV15HP. The DS1200 is also close to it's 17.8 mm xmax/excursion.
Keep in mind the DS1510 might do quite a bit better in a 6 cu ft box than the DS1501 in the graphs above, without knowing the specs of the DS1510 there is no way to know for sure.
It is certainly plausible that the lv12r is only 6db down from the FV15HP, hopefully Rythmik will get the DS1510 specs up in the future, so we can confirm that.
It certainly appears that Rythmik's Frequency response claims either aren't anechoic or they include a lot of eq.
Eq would of course decrease available output before reaching xmax or running out of power.
The Rythmiks certainly seem to use efficient drivers. Xmax isn't top of the line but it is certainly very respectable. It would be nice if all sub manufacturers published specs like this but I suppose that would probably put a few of them out of business Edited by Mik James - 6/17/13 at 10:58am