Upgrading sub to get a live feel.

16 x 30 is the room size.

I prefer sealed subs, but the Audiokinesis Swarm was designed as ported, with the option to seal the port with a plug. The set up used by the designer has the woofers facing the wall as jtcf mentioned. When I used a Swarm like set up I had woofers facing into the room and towards the wall. Even had one next to the listening seat and anyone who came over for a listen, including a friend who designs and sells speakers, couldn't hear any of the subs. He had to ask where the 4th sub was located and when I told him to look over the side of the arm rest he chuckled when he spotted the sub.

In my set up now the two front woofers face each other along the front wall, the other two woofers are next to the speakers and face out into the room per a method recommended by mijostyn who has posted on this thread and other sub threads. Both methods work well for me, but given the type of speakers (line array) I am using now the newer method has resulted in increased bass response and more 3D imaging. If I go back to point source speakers I will go back to an asymmetrical arrangement.

They are 6 inches away from the wall, and I'll turn everything down and see how it goes. 

When the SB were originally set up they added additional headroom to the speakers, without being heard were my standards. 

This has been a great thread,  Not too long ago I added a second REL T5 to my Omega Super Alnico Monitors, and things have been sounding really great (16 x 26 room with 8 ft ceiling and open on two sides).  Since reading about the Swarm package and various threads about setting up a dba, I’ve been interested in adding a third subwoofer next, and eventually a 4th.  The question I have is this:  would I get better better bass improvement adding a 3rd T5, which has a single sealed 8-inch driver, or try to get a larger (10 or 12 inch) sub for the third sub? The current subs are run in stereo.  As the new sub would be run off both channels, would I need to reconfigure the others to also run off both channels, or should keep them in stereo.

Hello ihor,

     I would suggest running all three subs in mono and adding a larger 10 or 12 inch sub for your third sub would be the best choices.  
     There are virtually no current or past music recordings in any format (vinyl, cd or hi-rez files) that contain stereo deep bass, all of the bass below about 80-100 Hz is summed to mono on the recordings since humans are unable to localize (tell exactly where the bass is coming from) on bass tones below about 80-100 Hz.
     Even though all three subs are outputting mono bass, you'll perceive the bass as a form of stereo bass, with the sound seeming to come from the proper bass instruments within the soundstage illusion ( for example, the drums are located in the center rear of the soundstage and the upright acoustic bass is located in front of the drums and off to the left.). 

      This is because, even though the fundamental deep bass tones below about 80-100 Hz coming from the subs will not be able to be localized, the related bass harmonics or overtones of the fundamental bass tones coming from the main speakers are able to be localized (since they extend above the 80-100 Hz limit).  Our brains are able to associate the higher frequency bass harmonics/overtones with the much lower frequency bass fundamental tones and thereby determine where the much deeper fundamental bass tones are originating from. This process is one of the principles of he science of psychoacoustics (how our brains process sounds and form perceptions).
      Having a larger 10 or 12 inch sub as the third sub also relies on psychoacoustics and will give the perception that the overall in-room deep bass response has been extended a bit deeper.  
     Proper positioning within your room and the proper setting of the volume, crossover frequency and phase control of each sub are very important for optimizing bass output in your room and integration with your main speakers.

Tim

Tim, thanks for your response.  This makes sense.  Looking forward to pursuing this dba!  The positioning and setting crossovers, phases, and volume will be the ultimate task and key to success.