Rythmik's subs have excellent transient response and overall sound quality. They are well engineered and they are a fantastic value.
I think there are still a couple of really nit-picky things where they could improve - their limiter (the device that stops the sub from destroying itself when you crank the volume to INSANE levels) is a tiny bit unrefined (it'll sometimes noticeably turn on, audibly reducing the volume, or it will remain on for a moment after the volume has decreased, leading to a sudden boost in volume when it turns back off...totally not an issue unless you're pushing the sub to its output limits though!) and they don't have quite as fancy or as long a feature list as something like SVSound's newest "Sledge DSP" amps.
BUT, their perfectly adequate (actually more feature-rich than something like Epik's extremely basic and kinda cheaply-made amps) amplifiers mean that you get a lower price while still getting excellent performance, so it all leads to that fantastic, high value!
I'm a bigger fan of Rythmik's ported subs (especially for home theater) than their sealed subs. The sealed subs are very good, don't get me wrong! But they ARE limited in their maximum extremely low bass output. Rythmik's ported subs are a cut above, IMO. They have better transient response and overall sound quality than most ported subs, but you gain that awesome super deep low end, which is a real treat for movies!
So with a 60/40 split with 60% of your content being movies, I think a Rythmik sub would be an EXCELLENT choice. BUT, I would personally prefer a ported Rythmik for that application - the FV12 or FV15. The smaller FV12 would be just fine in your room size. A pair would just offer the possibility (with proper setup) of more even and smooth frequency response at multiple seating locations rather than just one, lone "sweet spot"
For the price, it would be darn tough to find a sub that would perform better for both movies AND music (since you have a pretty even split).
