two subs, 1 or 2 enclosures ?

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quick question;

is there any benefit from having two subs in one enclosure ?
let me elaborate:
I've got 2 x infinity perfect 12.1 12" subs

Data sheet states 1cuft for 1 sub (sealed).

is there any performance difference if I put 2 subs in one 2 cuft enclosure
or 2 subs in the same enclosure with a divider, giving each sub 1cuft ?

Had a trawl online and can't find any real pros / cons, other than if one sub goes pop in a common enclosure it could also pop the other sub due to change in compliance load.
Cant (won't!) separate the subs out into two separate 1cuft enclosures, as they are going in a pre defined space, so even if they end up as 2 x 1cuft enclosures 'glued' together they will stay in the same place.

over to the experts !
 
With 2 woofers in one box one can load them push-push which gives you active vibration control, but the advantages of having 2 woofers placed to smooth the in-room response will usually out weigh that.

dave

I firmly will agree with the above. You can manipulate a room more effectively your bass sounds fuller because youll be excite more modes, fuller sound often results, better in room response.

Thats harder to accomplish it isnt as effective with one sub box placed in one place. However when everything in your room seems to be aligning including how the subs respond to room it can be quite good too, especially opposed to no sub at all, say just a pair of full rage speakers doing it all.

2 cabinets gets better, and better, try adding an analog eq. or DSP. you may wonder how you got by without one.

I heard a system with 2 x push pull m&k 150's wired in stereo in opposing sides of a room. what an effect it immerses you with bass, tuneful bass, audible and physically. The best systems I heard happen to be 2.2 setups.
 
Oh yea forgot to add the vibration control can be achieved with 2 subs one cab also, with a sub driver installed at each opposing side. Mirage makes some VERY nice sounding subwoofers that employ that method. This one Im about to upload has 2x10 passive subwoofers in a sealed cabinet, the cabinet is 2 channel. I never heard it or knew it even existed and being more familiar with some of their later subs, also sealed. Thats one company that got speaker and sub making bang on.

If you go into mirage's archives you can dig up a write up if interested.
 

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OK - so it sounds like 2 separate cabs are the way to go. might have to see how I can accommodate that !

Its a studio monitor setup, so the need for tight accurate bass is real :)
I'm using Soundcraft monitors, Bi-amped fed from DCX2496, room RTA'd with a DEQ2496 & individual drivers time aligned.
Current Sub is an 18" ported enclosure; it's not bad but isn't as accurate as I need, hence the 2 x 12" sealed enclosure question !
 
Studio, flat, beauty. I like your choice of going with a sealed system be it acoustic suspention or push pull, or fourth order bandpass.

If its crisp tight accurate tuneful bass desired going sealed with some balls on the amp and some type of bass management system sealed is one of the better ways of achieving it. I also seem to like leaning more towards paper cones. They have a way of sounding so natural to me, as if to be sitting in front of a kit, that realistic they put chills down your neck. I love being a bass head.
 
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frugal-phile™
Joined 2001
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not sure I understand the first part - 'active vibration control ' - ?

If you mount the 2 drivers on oppossite sides with the magnets tightly coupled, then the reactive force of one driver is countered by the other driver’s reactive force instead of getting loaded into the box.

Best sketch i could find: The green brace is contoured to tightly couple the woofers.

push-push-extremis-cube.gif


If you have only a place for one woofer then by all means go push-push.

dave
 
Having the drivers exactly opposite while physically tying the two magnet structures... I would tend to think is a bit of a red herring, a solution to a poorly fabricated enclosure.
With two identical drivers the "best" solution I think would be the face to face push-pull design. This arrangement may or may not work as one needs to "run the numbers" to see what the simulations say. The push-pull cancels out asymmetries of the pressure wave by having the cones facing each other, the small pocket of air sealed off.
Have we done any sims on these ?



---------------------------------------------------------------------Rick.......
 
Just for the fun of it, I ran this driver written as Infinity Kappa Perfect 12.1 ...the simulations have an EBP of 50.7 a flexible driver as it splits the two between running best as sealed or ported...the sealed version performed poorly, a small box for sure, the ported version does much better, a face to face push-pull with the two drivers, ..Size of enclosure at 60.76 Liters, fb, the tuned frequency at 20.96 Hz., a -3Db of about 18.5 Hz, great low-end extension. I still have to rework how I'm going to integrate a .8 meter long port into this design.

Bumping up the enclosure size to 90 liters, works fine, makes the port at 102mm in diameter, at "only" 548 mm long. Still juggling things

----------------------------------------------------------------------Rick...........
 
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mirage bipolar-400. they stayed with the design through the years.

Maybe some different subs are a good idea? Not all suit all applications as well, or nearly in some cases.
 

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thanks Richard - I've been running a single 12.1 for some years in a 1cu ft sealed enclosure - with the room effect the extension is quite low. I'll trade some LF Extension for tightness though :)
As for Isobariks - I have a pair of 1988 Linn Isobariks. Full active (6 amps per speaker !) RTA'd & active crossover.
my reference point :)
 
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