Hello smodtactical,
I agree with bdp24, that four Rhythmik F12 subs would perform well in a DBA configuration and that four F18 subs would likely perform just as well but with a bit more deep bass power and impact.
I think it's important for you to understand a few facts about how humans perceive bass:
1. We can generally not locate bass tones (determine exactly where the sound is coming from) below about 80 Hz and the deepest bass tone we can generally hear is 20 Hz, Our bodies can feel deeper bass tones below 20 Hz but we generally can't hear them. Also, there are very few musical instruments that are even capable of producing bass tones below 20 Hz, pipe organs are the only ones I'm aware of.
2. Because of this, we perceive all bass under about 80 Hz as mono and not stereo. Recording engineers have known this for decades and have been summing all bass below about 100 Hz, as well as filtering out bass frequencies below about 20 Hz, since the 1950s. This is also why you can safely disregard any suggestions of positioning subs in your room like main speakers, with a carefully positioned left and right speaker.
In other words, there's no such thing as stereo deep bass. Best in-room bass results will be achieved by operating your subs in mono mode and positioning each sequentially for optimum bass performance. I can explain exactly how to do this, regardless how many subs you ultimately choose to utilize in your room, in a future post.
3. Virtually all commercially available musical content produced in the last 80 years, has the bass below about 100 Hz summed to mono and bass below 20 Hz filtered out. So, even if you did place your subs in a left and right stereo physical configuration, there's a complete lack of content with stereo deep bass to play on them.
My main point, again, is to disregard any suggestions or notions of positioning or operating your subs for stereo playback. Just operate them in mono mode and position each for best bass performance.
Beyond the above, it mainly comes down to cost and convenience. The Audio Kinesis Swarm 4-sub DBA system costs $3K and will produce high quality bass in your room down to the audible limit of 20 Hz. I've never auditioned any Rhythmik subs but believe they are high quality subs at reasonable prices. I also think it's likely that utilizing four F12 or F18 subs in a DBA configuration in your room would outperform the Swarm complete system.
Of course, the decision is completely up to you. I just want to make sure your realize that either Rhythmik option option will cost significantly more and will be less convenient to setup since you'll need to set the volume, frequency cutoff and phase controls separately on each sub, rather than once for all four subs on the Swarm.
However, I also believe that utilizing two F12 and two F18 subs would perform very nearly as well as four F18s in your room, helping with the cost but not the convenience.
Later,
Tim
