For those thread readers interested in trying out the 4-sub DBA concept in their rooms, I think it's simplest just to buy a complete DBA kit like the Audio Kinesis Swarm or Debra systems for about $3K. These systems consist of 4 relatively small subs(the Debra subs are each 12"dx14.5"wx18"h, weigh 44 lbs, have a 10" aluminum long-throw 4 ohm driver), a set of 4 sub port plugs for either ported or sealed sub operation and a 1,000 watt @ 4 ohm class AB sub amp/control unit with a volume, crossover frequency and continuously variable phase controls. This amp/control unit also has a limited band equalizer, left/right and LFE unbalanced rca inputs as well as 2 sets of speaker terminal outputs.
The AK Swarm and Debra 4-sub DBAs are both high quality systems. However, it's also possible for individuals to build a high quality custom 4-sub DBA system either as a DIY project, with the sub amp and all sub component parts sourced from retailers like Parts Express, or purchasing 4 self-amplified subs of one's own choice of quality and expense.
Just like everything else in home audio/video, quality matters, obviously varies between specific products and is very important in determining performance results. Millercarbon took the DIY route option, buying the exact same Dayton SA-1000 sub amp/control unit that the Swarm/Debra DBA systems use for less than $400 from Parts Express, sourcing his own sub cabinets and drivers and building his own custom subs. He and Duke agreed the drivers he purchased and used were more expensive but also even higher quality drivers than those used in the Swarm/Debra subs.
A second custom 4-sub DBA option is to buy the sub amp and 4 passive (unamplified) subs of one's personal quality/expense choice and then follow the sub positioning and amp configuration instructions detailed on my prior thread post. It's important with this option to ensure the sub amp has the required volume, crossover frequency and continuously variable phase controls.
Finally, a third custom 4-sub DBA option is to just buy 4 traditional self-amplified subs of one's personal quality/expense choice and then follow the sub positioning and amp configuration instructions detailed on my prior thread post. It's important with this option to ensure all 4 of the self-amplified subs have the required volume, crossover frequency and continuously variable phase controls; as well as realize that this option requires the user to set these 3 controls individually for each of the 4 subs rather than once, for all 4 subs as a group, like on the prior options.
The good news, however, is that some newer self-amplified sub brands even have the very useful added feature of being able to be configured to work together in a group in what is unfortunately termed a Master-Slave relationship, which functionally means the control settings made on the Master unit are able to be mirrored on each Slave sub able to be attached to the Master in a daisy-chain method. This is a very useful feature if one's attempting to create a multi-sub DBA system.
Tim
