My experience adding subwoofers to 2 channel

Ok, DBA SWARM subs are absolutely the only way to go I wish I had the cojones to take my 200 lb subwoofers and their 2000 watt amplifiers and toss them up in the air to let them play wherever they land happily ever after. But I am an old man and to stupid and weak to lift these things never mind throwing them up in the air.
I'm sure you guys are on gluten free diets. You need to switch to now to Keto!

Hello mijostyn,

     I’m running all 4 subs in mono with a xover frequency between 40-50 Hz and a filter slope of 12 db/octave, usually configured for a 40 Hz xover for music and 50 Hz for ht. My main speakers are Magnepan 2.7QRs that each have a 620 square inch planar-magnetic dipole bass section but they only extend down to 35 Hz. I run these full range with a pair of D-Sonic M3-600-M mono-blocks rated at 1,200 watts each at 4 ohms. This combo produces very accurate and high quality bass on their own but I added the AK Debra 4-sub DBA system for added bass impact and increased dynamics.
     Since the 2 bass sections only extend down to 35 Hz, I don’t consider them extra subs in the room but I do think they help on the overall bass quantity and quality in my room; for example, hearing the initial pluck of an upright bass’s string followed by hearing the deeper bass produced by the body of the instrument and finally the natural decay.
     Subjectively, I perceive the bass as very accurate in tone, detailed, extended, dynamic, smooth and natural with an impact that is felt as well as heard. I don’t detect any bass muddiness or have the sense that the bass is too slow, lagging behind or disconnected from the rest of the reproduced spectrum. 
     However, I’ve never had the in-room frequency response measured but I would be very surprised if it didn’t measure well.  I do have pictures of my room and system on my profile if you’d care to look and my room is 23 x 16 feet with 8 foot ceilings.


Thanks,
Tim

I have known Duke LeJeune for quite some time now, even owning his Jazz Module speakers for several years and using his speakers in my exhibit rooms at audio shows. Earl Geddes was his mentor and while Duke manufactures box speakers, he has a pretty good understanding of ESLs having used the original Quad ESL in his research (the speaker that replaced my Jazz Modules) and being one of the more prominent Sound Lab dealers. I think he has a good grasp on sound dispersion and how to maximize it. In addition, I should mention I had never been keen on using subs in my system even though I was well aware of Duke's initial work developing the Swarm.

The last show I exhibited at with Roger Modjeski we used his ESL speakers which by default had to have subs since they only went down to 100 Hz. Roger designed a sub with an 8" driver in a 0.3 cu. ft. sealed box (air resistance) and used two to compliment his panels in a bi-amp set up with the Beveridge RM-3 crossover he designed for the 2SW speakers long ago. After hearing this I followed suit but decided I would expand to 4 subs to replicate the DBA of the Swarm. For the last few years I have enjoyed this set up with both the Quad ESL and now my modified Acoustat Model 2 speakers.

However, I was intrigued enough by mijostyn's set up that I contacted him and he sent me a photo so I could visualize it. I would like to add that I was not unhappy with my DBA set up, but since he was also using Acoustats (they are essentially a bigger version of my Model 2s) I felt this was worth a try. Over the past few days we have been communicating and he has helped me tweak things to get the set up just right. I have been listening on and off since last evening and have to say I am impressed by what I hear, the primary difference being what I feel in the low end. So I would like to thank mijostyn for his contributions to this topic and help getting me there. I will try to post more on this as I continue my listening.

Hello clio09,

     I'm very impressed with mijostyn's linear/line array sub system and I've never even heard one in a home system, although I'd love to.  
     I'm also very interested in in your bass system build with your Acoustats that mijostyn is very kindly assisting you with.  I'm also very happy with my DBA system but would be tempted to try it if I had the clean slate of a dedicated room.  My combo music and ht room is also my living room.  My 4 subs are currently very inconspicuous in the room which I think is very cool, because you only hear and feel them when there's prominent bass content on music and ht being played, and my wife can live with.
     As I understand line array bass systems, the subs would be aligned across the front wall of the room and my 6x2 foot Magnepans would also be positioned about 4-5 feet out from this front wall.  I'd be okay with it but my wife's opinion of this in our living room would likely be expressed by a sturdy frying pan smacking my skull. 
    But I wish you only the best on your build clio09 and hope you and mijostyn enjoy your linear array bass systems very much.

Please do post updates.
Thanks,
  Tim

My subs were built a while back, mijostyn helped me set them up for optimal performance in the line array. His subs have quite a large footprint, as do his speakers which are probably the best Acoustat model in my opinion. They line array per mijostyn is actually a semi circle as opposed to all of the subs being against the front wall of the room. A very interesting set up and one that does require some attention to detail. I appreciate mijostyn’s patient with me.

In my room the DBA did work well for my needs, and it wasn’t a difficult system to set up. My only nit was that my room constraints didn’t allow me complete freedom to place the subs anywhere I wanted. The sound was quite good though. I am embarking on building 4 new subs using a 10" driver and look forward to going to the audio show in Long Beach to hear Duke’s Swarm in person.