Zero reason to have your sub be the same brand as your speakers. I would certainly recommend that you get your center speaker from Klipsch if you are using Klipsch front speakers. Klipsch speakers are considerably more efficient than a lot of other speakers, and that horn tweeter doesn't match easily to other types of tweeters. So for the sake of "voice matching" your front soundstage and being able to keep output settings consistent, definitely match your center to your front main speakers.
But the subwoofer, that can most certainly come from a different brand. If you love the look of the SVSound cylinder subs, I can certainly vouch for their performance. The new PB13-Ultra DSP I found to be EXTREMELY impressive, and the PC13-Ultra DSP cylinder version should be close to identical. SVSound really is making the best subwoofers they've ever made in their history right now, and I personally really, really like the new Ultra models.
Output would be NO problem, even in a very large room. If you can manage to afford and position two subs, that would help to even out the frequency response over more than one seating position. You have to be able to position them both correctly for this effect though, the mere act of having two subwoofers in a room does not guarantee any sort of improvement
With that hard floor surface, it's going to be VITAL that you decouple the subwoofers from the floor. I should hope that an extra $50 for an Auralex SubDude will be a "no brainer" in your case
The SVSound Plus subs are amazing, but I'm just really excited by the Ultra models even more. That 13" driver is something to behold, and the sheer tactility, control and raw power of the Ultra models put them over the top for me.
The Funky Waves subs are gorgeous and built like tanks. But they don't have the same sophisticated circuitry and programming of SVSound's new "Sledge" amps. The engineering on those "Sledge" amps is something else, and it literally guarantees that you cannot "over drive" the SVsound subs or even get them to audibly distort. It's an amazing level of control and design.
So my vote is for the SVSound PC13-Ultra with an Auralex SubDude decoupling it from the floor. If you can manage two of them and position them optimally for more even response at more seating location, that's even better!
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