Subwoofers facing each other?

[3DUPMIX]

Does anyone see a problem with facing subs at each other? I am working on a room 14'10" in width. The client has a pair of M&K MX-5000 subs that he wants to use. They are in perfect condition but they are large... in particular they are roughly 25" deep. We are building a screen wall for an 11' wide screen but don't want to face the subs into the room because of their +25" depth. We would have to move the screen wall further out from the existing cement block wall. The width of the sub on the other hand is only 15-1/4". So, the question is can we put them in the screen wall "sideways" so to say? see attached drawing. Thoughts / ideas? Thanks!

 

[ryanosaur]

I can’t claim expert status, but I would be concerned the soundwaves hitting each other in the middle might create some other acoustic consequences in terms of cancellations and such.
Hopefully somebody else can chime in on that.

as front wall isn’t always guaranteed to be the best acoustic home for subs, is there a way to put one Sub somewhere else in the room?

 

[3DUPMIX]

Thanks for the response. The phase relationship is important. Per the drawing, the subs face each other with roughly 11-1/2 to 12ft in between filled with R-38 / R30 batt. But I wonder about firing into the room vs. “sideways” facing each other? What would I lose? Would I lose anything? Is this an acoustic mistake with hidden consequences?


Sent from my iPhone using Tapatalk

 

[ryanosaur]

I’ve never had to play with the phase on my subs. Perhaps a slight phase change may help avoid a problem.(?) Again, that’s above my pay grade.

Personally, I’m a fan of a Geddes style approach: move the subs off the front wall and place them strategically and asymmetrically around the room so that your low frequencies are not hitting any boundary or each other in a manner that may encourage cancellations. Moreover, by finding the best places in the room, acoustically, to place the subs, you should excite the most room modes simultaneously, thereby minimizing the occurrences of standing waves (especially across the listening positions).
Since I’m not super experienced with REW yet, for example, I haven’t been able to practice the measurement aspect yet. However, with 4 LF sources (in the way of 2 Subs and 2 near-full range towers), I have them all different distances from each other (including a slight asymmetric placement for the towers). I utilized the Sub crawl to help identify the best placement for the subs. All told, I have a fairly respectable LF FR in my room. I’ve seen better from some, but I’ll take mine with a smile!

Regardless, I’d recommend, if possible, setting up a crawl in that space if you can. Find the actual best acoustic places for LF in that room. If nothing else, it may be educational just to experience how the LF behaves in that room, especially where you are looking at placing the subs right now.

(Btw, unable to access that file on my phone... I’ll try to look later!)

Cheers!

 

[mtrycrafts]

If you are restricted to that 25" space, angle the sub out to the point of the outfacing corner is just touching that wall or curtain, whatever that part of the wall is made of.
don't forget, the sound waves travel in a hemispheric shape away from the driver.

 

[TLS Guy]

I’ve never had to play with the phase on my subs. Perhaps a slight phase change may help avoid a problem.(?) Again, that’s above my pay grade.

Personally, I’m a fan of a Geddes style approach: move the subs off the front wall and place them strategically and asymmetrically around the room so that your low frequencies are not hitting any boundary or each other in a manner that may encourage cancellations. Moreover, by finding the best places in the room, acoustically, to place the subs, you should excite the most room modes simultaneously, thereby minimizing the occurrences of standing waves (especially across the listening positions).
Since I’m not super experienced with REW yet, for example, I haven’t been able to practice the measurement aspect yet. However, with 4 LF sources (in the way of 2 Subs and 2 near-full range towers), I have them all different distances from each other (including a slight asymmetric placement for the towers). I utilized the Sub crawl to help identify the best placement for the subs. All told, I have a fairly respectable LF FR in my room. I’ve seen better from some, but I’ll take mine with a smile!

Regardless, I’d recommend, if possible, setting up a crawl in that space if you can. Find the actual best acoustic places for LF in that room. If nothing else, it may be educational just to experience how the LF behaves in that room, especially where you are looking at placing the subs right now.

(Btw, unable to access that file on my phone... I’ll try to look later!)

Cheers!

Subs are omnipoles. That means they are 100% omnidirectional. The only thing you don't know if that is the optimal position for the subs. Facing them towards each other is of no concern. Somehow you need to find the optimal spacing before finishing.

 

[ryanosaur]

Subs are omnipoles. That means they are 100% omnidirectional... Facing them towards each other is of no concern.

I do understand about the general behavior of the large wavelengths in small rooms, just wasn't certain if the direct opposition at that distance would pose a problem.

The only thing you don't know if that is the optimal position for the subs... Somehow you need to find the optimal spacing before finishing.

This!

 

[lovinthehd]

Orientation wouldn't matter nearly as much as placement in general. Both on the front wall isn't necessarily the way to go at all....