So....I got my second pair of XS15s on Wednesday. Spent the afternoon and all the next day pushing, measuring and calibrating. I think I've got them dialed in pretty good. Watched some scenes from Pacific Rim, Total Recall and Word War Z and it sounds really, really good. I watched Iron Man 3 (first time) all the way through and is it just me or does that movie not have as much LFE as you would expect? Still considering getting a Mini DSP.
I originally had a pair of Velodyne F1500s (for the past 20 years), great subs for their day! After one died, I decided to buy the first pair of XS15s which I was planning on using exclusively and paying forward the old Velo - but after integrating the remaining Velo with the PSAs the results were quite satisfying so I kept the Velo in the mix.
Fast forward a few months and the sole remaining Velo died - I immediately noticed a hole in my bass response that no amount of tweaking with the 2 PSAs could remedy.
I decided I would replace the dead Velo with a new XS15 - then the thought kept creeping into my head that I should get 2 more PSAs...I was pretty sure one more would do the job, but I didn't want to be left always wondering, "what would 4 sound like?".
Anyways, after integrating all 4 PSAs I've come to the conclusion that 3 really would have been "enough" and that 4 subs is NOT twice as good as 2 subs...that being said, I'm still happy I got 4! The bass is quite a bit smoother now, and my wife's seat actually now has a better response than mine! (I may just have to do something about that one.)
I did expect a bit more output than I'm getting, although I really haven't had a chance to crank it up yet...hopefully this weekend.
I'll post some pics and graphs this weekend.