Subwoofer Question


I currently have a Martin Logan Balanced Force 210 sub paired with Dynaudio Contour 3.4 LE speakers and a Prima Luna HP Dialogue integrated amp.  My listening space is fairly small (listening position is about 11 feet from the speakers.  The nature of the room only allows me to place a sub in the front corners of the room near the speakers so I can really only have two subs.  I have been toying with the idea of selling the ML and replacing it with dual subs, one in each front corner.  One particular sub I have been thinking and reading about is the REL t9i.  Why am I thinking about this? No other reason than the itch to tweak but certainly also to improve.

I would greatly appreciate this board’s thoughts and insights.

Thanks,

puppyt
Ag insider logo xs@2xpuppyt
What drivel? He’s right. Call him out on what? You haven’t said anything! Talk about drivel!

Everyone here should be praising Tim. The DBA concept he’s explaining is not an easy one to understand. It flies in the face of all our accepted wisdom about timing and matching and symmetry. There’s no marketing angle because the advantages of using lots of subs overwhelms any one sub however good it may be. Its a hard sell not because it doesn’t work, but because it works so well its hard to believe how well it works!

The only thing DBA has going for it is that it does in fact actually work. Nothing else really does. Not really. For sure not anywhere near as good. Its physics: you put one sub in a room, you get one set of lumpy bass modes. The more subs you put in the room the more and the smaller and therefore the smoother the modes. Its not drivel. Its science. You should try it some time.
I think a lot of folks make the mistake and assume that all rooms sound the same when it comes to subs. The more subs in the room, IME the easier it is to overload the room....and this really needs to be taken into consideration. Having said that, it is also true that two subs can flatten out the bass response in a room...assuming that the subs are a suitable size for the room.
Since the OP has limited options of placement in his room, I would think that if he is willing to add room acoustic treatments and is considering the high level connection on the REL T9i that he will be on the right track, imho.
Daveyf1 wrote: " The more subs in the room, IME the easier it is to overload the room....and this really needs to be taken into consideration. "

If we’re talking about a setup where the user is careless with the level control for the sub(s), then I suppose that’s true.

However in a setup where the user takes care in setting the level of the sub(s), the improved in-room smoothness of a good multisub setup makes is less likely that a peak will "bloom" and overload the room.

That being said, there is a situation in which multiple subs might result in a rising bass response as we go down in frequency: Near the top of the bass region the outputs of the distributed subs will be combining in semi-random phase, while down at the bottom end of the bass region (where the subs are a relatively small fraction of a wavelength apart) their outputs are combining much closer to in-phase. Approximately in-phase sources combine more efficiently than do semi-random-phase sources. So if the individual subs are more or less "flat" across the bass region (not counting room effects), the net result can be too much output down at the bottom of the bass region. Fortunately the solution is fairly simple: Reverse the polarity of one of the subs, which not only corrects this in-room bass rise, but also improves the in-room smoothness. I suggest reversing the polarity of the sub which is farthest from the main speakers.

Duke
commercially affiliated with a multisub system
noble100: "Virtually anyone with fairly extensive experience utilizing more than 1 sub in their room and system, will agree that 2 subs perform twice as well as a single sub and 4 subs perform about twice as well as a pair of subs." 
clio09: "LOL. This one's a classic. Most of the time I avoid your drivel so you probably said this before multiple times and I missed it. Just had to call you out on it this time. LOL."

Hello clio09,

     Please excuse my drivel that tends to get your panties in a bunch.  I have chosen to ignore the sticks and stones you have thrown, btw like a sissy, in my general direction. 
      I'm not exactly sure what your major malfunction is, but I believe it may have something to do with me completely and factually shutting the door on your notions about the existence of true stereo deep bass below about 80 Hz.  Facts can be such stubborn, enlightening and inconvenient counterpoints to notions of nonsense sometimes.  
     Fortunately, your avoidance. obfuscations and denials of the scientifically and anecdotally proven truths contained in my quote above, have no effect on their veracity.  

Tim 
While I am a huge advocate of acoustics treatment, the op mentions they have a small listening space  (Hey op, what are the measurements). Good, emphasis on good, bass control with acoustic treatments means large acoustic objects. That may not be feasible in the space. With the exception of resonators, which can still be large to be effective, or too narrow band, any absorber is going to be big.  With two subs, the nodes will be much less pronounced and easier to control with acoustics.

erik_squires8,841 posts04-17-2020 1:59pmSpend all the money you were going to spend on a 2nd sub and treat your room first. Talk to GIK. Then see if you still feel a 2nd sub is needed.