tn just published the results for the twin svs 20-39 with 600 watts amp and it shows that the twin package is on par with the stryke at almost all levels. the stryke looses badly at 25hz, but it does have healthy output at 16hz. figures at 16hz were not provided for the twin svs package but i estimated them to be around 90 db or less. Other than those frequencies both system are about equal across the board. I know the stryke wasn't tuned optimally so my first question is how much can it improve by beitn optimally tuned. You might be asking why I am dissapointed because keeping up with a dual svs package should be rather impressive. well the stryke even if you build it yourself you have to drop out 1500 to get the performance that is shown on the chart. The dual svs package is already less than that or you could buy twin hsu vtf-2 and get compareable performance (just add 6 db accross the board). I know the stryke box does not take as much space away as the dual svs setup but when you are building it yourself you should be able to beat any commercially available subwoofer in every category. Not to mention stryke is planning to sell a completed single passive 15" stryke for $3000. after you add the amp and xover/eq you have already invested more than $4k and you have a setup that is merely on par with the regular twin svs package. I just hope that the proper retuning of the stryke will give it a 3-6db boost in the 16-32hz range. That alone would it make it worth the 1500(diy) or 4000(retail) dollar price tag.