Urgent Help with Bass Bin Phase

[OllieJames]

Hello!

Just picked up some subs from a mate and am unsure what position to have the phase switches in. Any ideas? I'll be having my Mackie's on top of them on poles.

Thanks for your help :)

Ollie

[kjdiscos]

what bins have you brought ?

[Tom]

For most gigs, you would want the speakers in phase, but having said that you can turn them out of phase and get better bass response. Depends on the venue really. I always try both when using my active sub to get the best bass. :)

[OllieJames]

what bins have you brought ?

Hi, the subs i'm using are Wharfedale EVPx15PB


For most gigs, you would want the speakers in phase, but having said that you can turn them out of phase and get better bass response. Depends on the venue really. I always try both when using my active sub to get the best bass. :)

Hey Tom,

So when you say in phase, the switch is at the 0 position? I'm going to set them up today with my Mackies, i just wanted to make sure that no damage could occur if i had the phase switch set incorrectly!

[music-2-play]

No, don't worry, nothing bad will happen - the worst that would happen from a audible sense, is if you have two of the subs next to each other and one has the phase switched, there will probably be a drop in the overall perceived bass level being put out by the two, as one is cancelling the other out.

As one speaker cone is pushing out (compression). The other is moving in (refraction). In theory, you shouldn't hear anything (though in reality, the bass will probably just sound more hollow and washy), as your eardrums are having the same force pushing on them, as they have pulling on them --- hence, no movement and no sound heard.

As to why subwoofers have a phase switch --- depending on how far the subwoofer is from the tops, it may help to reduce phasing in the "crossover frequencies", that will come from the same sound hitting you ears at a slightly different times - Sometimes completely reversing the phase of these frequencies, will create a more solid sound in these crossover frequencies and because there's a significant time delay between the sub and tops reaching the listener, there will not be significant phase cancellation like that that would occur if two out-of-subs are placed next to each other. If a sub crosses over at 120hz, that's where a lot of the body of a kick drum lies, so it could potentially make a difference to your sound.

This is a complex daunting topic and even with seven years as a recording studio geek, I still only have what I consider a superficial knowledge of acoustics.

[OllieJames]

No, don't worry, nothing bad will happen - the worst that would happen from a audible sense, is if you have two of the subs next to each other and one has the phase switched, there will probably be a drop in the overall perceived bass level being put out by the two, as one is cancelling the other out.

As one speaker cone is pushing out (compression). The other is moving in (refraction). In theory, you shouldn't hear anything (though in reality, the bass will probably just sound more hollow and washy), as your eardrums are having the same force pushing on them, as they have pulling on them --- hence, no movement and no sound heard.

As to why subwoofers have a phase switch --- depending on how far the subwoofer is from the tops, it may help to reduce phasing in the "crossover frequencies", that will come from the same sound hitting you ears at a slightly different times - Sometimes completely reversing the phase of these frequencies, will create a more solid sound in these crossover frequencies and because there's a significant time delay between the sub and tops reaching the listener, there will not be significant phase cancellation like that that would occur if two out-of-subs are placed next to each other. If a sub crosses over at 120hz, that's where a lot of the body of a kick drum lies, so it could potentially make a difference to your sound.

This is a complex daunting topic and even with seven years as a recording studio geek, I still only have what I consider a superficial knowledge of acoustics.

Wow, thank you!

I've been doing bits in a recording studio too (tracking and mixing) but am learning all the time!

Thanks very much :)

[Shaun]

No, don't worry, nothing bad will happen - the worst that would happen from a audible sense, is if you have two of the subs next to each other and one has the phase switched, there will probably be a drop in the overall perceived bass level being put out by the two, as one is cancelling the other out.

As one speaker cone is pushing out (compression). The other is moving in (refraction). In theory, you shouldn't hear anything (though in reality, the bass will probably just sound more hollow and washy), as your eardrums are having the same force pushing on them, as they have pulling on them --- hence, no movement and no sound heard.

As to why subwoofers have a phase switch --- depending on how far the subwoofer is from the tops, it may help to reduce phasing in the "crossover frequencies", that will come from the same sound hitting you ears at a slightly different times - Sometimes completely reversing the phase of these frequencies, will create a more solid sound in these crossover frequencies and because there's a significant time delay between the sub and tops reaching the listener, there will not be significant phase cancellation like that that would occur if two out-of-subs are placed next to each other. If a sub crosses over at 120hz, that's where a lot of the body of a kick drum lies, so it could potentially make a difference to your sound.

This is a complex daunting topic and even with seven years as a recording studio geek, I still only have what I consider a superficial knowledge of acoustics.

Great post. I'll be honest, I never knew what the phase switch was for so I always left it well alone. Thanks for the helpful information.