Honestly, my vote (and what I would choose to buy if it were my money) in this particular situation is for the HSU VTF-2 MK4. Here's why:
- First up, the VTF-2 MK4's output capabilities are appropriate for that room size.
- 2nd, you've basically said you use your system for about 50% music and 50% movies/games. So you really want a "do it all" sub. One that can dig deep and deliver tactile impact for movies, but also one that has very tight transient response and high accuracy for music. The VTF-2 MK4 does a good job of finding that balance, plus, if you want to, you can alter its low end extension and maximum output by using the port blocks and tuning - although I think using 1 port block and the associated 18Hz tuning at all times will strike a good balance for your purposes
- 3rd, the VTF-2 MK4 is highly adjustable on the low end with the filters provided. In an apartment setting, this is important because you can basically EQ the low end with those filter options so that you do not get a large resonance or a huge room gain boost, which would undoubtedly end up disturbing the neighbors!
There are certainly some other, very good choices in this price range. The Rythmik FV12 remains my favorite $550 sub overall, but it is currently out of stock as Rythmik waits for more units to arrive from overseas. The VTF-2 MK4 also offers the option to run it in a high output 25Hz tuned mode with two ports open, or you can run it with one port in 18Hz tuning, or you can run it as a sealed sub now, which is a new option for HSU. That's some real flexibility from the VTF-2 MK4 that you won't find with other subs in this price range. Plus, the VTF-2 MK4 is just a good-sounding sub all around
The SVSound PB or PC12-NSD ported subs are tremendous for movies and deliver 20Hz extension and high output that is pretty much unmatched for its price point. But the NSD ported subs are not as adjustable. You can't run them sealed and you can't adjust their low end performance in any way. There's just the one 20Hz port tuning and that's it.
So the VTF-2 MK4 stands out in this particular case for me - mainly because you can adjust it so much. Rather than choosing a small, sealed sub that might not have enough output or 20Hz extension for you movie watching, or choosing a ported sub that might result in too much low end room gain or not have tight enough transient response for your music playback, I say to get a sub that can be adjusted to go either way and offers a terrific set of adjustable tuning options, port options and low end filters that will let you EQ the sub to your room and taste
