2 Subs in one room

[Barks]

If you had two subwoofers in one room (behind a normal 2.0 Hi-Fi setup) would you invert the phase (180 degrees) on one of the subs?

 

[asim18]

Wouldn't that just cancel it out?

http://en.wikipedia.org/wiki/Phase_cancellation#Constructive_and_destructive_interference

 

[LukeTW]

ignore.

 

[Barks]

So if you have one subwoofer working with 2 Hi-Fi speakers, how are you supposed to know whether to set the phase to 0 or 180?

Cheers

 

[MumboJumbo]

Its more complicated then that, phase is also dependent on distance away from each other. You need the soundwaves to move aplifying each other and thus be in phase with each other. Otherwize they will cancel each other out and you will get dead spots in the room.

 

[Barks]

So what's the gold standard of calibrating a subwoofer to a 2.0 setup?

 

[james.miller]

two subwoofers can be a nightmare to setup, although there are arguments for and against using two. as mentioned, phase depends on the distance of the subs *from where you are sitting* but it is never a case of you sit X meters away so you should set Y phase - its far more complicated.


Whats your reason for using two anyway? more often than not, the benifits of using two are vastly over-rated and it is often more beneficial, if you already own two, to sell them both and by one single better subwoofer.

So if you have one subwoofer working with 2 Hi-Fi speakers, how are you supposed to know whether to set the phase to 0 or 180?

Cheers

you play by ear thats about the best you can manage. Audyssey (if your amp has it) will only calibrate for one subwoofer. you'd need some expensive gear & software to calibrate for two.

Otherwize they will cancel each other out and you will get dead spots in the room.

you'd still get that with one subwoofer - you always get a dead spot and a spot where frequencies are amplified, it's just a much bigger issue with two subwoofers.