Phasing/Polarity

[bh4554]

I've looked around and read alot alot about reversing the polarity/phase of mic's when recording.


To me it seems like it's important when ambient miking guitars but crucially with drums becuase of the different distances oif mic's from the sound source.



HOW DO U REVERSE THE PHASE???? I can't find how to do this, and was just wondering if anyone could help me......

Thanks for any help, anyone can give me with this one and Merry Christmas!

 

[mshilarious]

HOW DO U REVERSE THE PHASE???? I can't find how to do this, and was just wondering if anyone could help me......

Thanks for any help, anyone can give me with this one and Merry Christmas!

If you don't have that feature on your mixer or preamp, most software will have a polarity reverse button.

Don't think this magically solves problems though. Get the placement of the mics correct.

 

[bennychico11]

the button will generally look like a zero with a slash through it. If I remember right it's the greek letter theta
anyway, if you don't have that, some software programs also have an inverse option which will do the same thing. You also can wire a cable with the pins wired oppositely (pins 2 and 3 wired together on both ends of the cable)...but make sure you label the cable correctly

 

[crankz1]

.... You also can wire a cable with the pins wired oppositely (pins 2 and 3 wired together on both ends of the cable)...but make sure you label the cable correctly

I know what you are meaning but the way you have worded it, brings some misunderstanding.

"(pins 2 and 3 wired together on both ends of the cable)" ... would turn it into an unbalanced cable of sorts.

I'm sure what you meant was to take one end of the cable and reverse the wiring for pins 2 and 3 on one end only.
If it's a TRS cable, you would reverse the wiring on one end for the Tip and the Ring.

The standard legend for XLR is ....
Pin 1 - ground
pin 2 - +signal
Pin 3 - -signal

TRS legend ....
Tip - +signal
Ring - -signal
Sleeve - ground

To reverse the phase of a cable, you just swap the + and - signal wires on one end of the cable. And yes .... label it as being phase reversed.

 

[bennychico11]

I know what you are meaning but the way you have worded it, brings some misunderstanding.

yeah, sorry...that's what i meant.
it was late

 

[bh4554]

thanks, now that all makes sense!

 

[freak1c]

in a sense it's incorrect to call polarity reverse buttons "phase reverse" buttons because phase is a time relationship and polarity has nothing to do with time,nevertheless they are commonly called phase reverse.
what they do is flip the waveform of a signal exactly upside down.they can help a little with phase problems, or not, best to move the mic.
a good example of phase is to listen to some music while moving one speaker further away or closer than the other speaker,you can really hear the frequencys drop out,while other freq.'s get emphasized,relative to speaker placement.anytime you use multiple mics you introduce phase issues,could be good,could be bad,but it's inevitable.
i use em to reverse the polarity on the top or bottom snare mic when doublemicing snares,in this case the waveforms are more or less opposite already and cancel each other to some degree,so using it here flips one.
also use em to a/b the sound when using room mics with the direct mics,sometimes it helps.

 

[tbone36109]

hey i have a question along these lines. i have to mics plugged into the same mixer and and im only running one input the the computerif the board doesnt have a phase inverter(its the alesis multimix 6fx) then is the only option changing the cables(or does anyone know how to do it on this board)

 

[Disposable]

Sorry to tag along on this but since we are talking about Polarity...
Why the hell does my guitar amp have a polarity button
And what the hell does it do?

I don't "hear" any difference, but that's not to say there isn't one.

If it helps at all to know...
It's an early seventies Kustom 150.
From what I can tell, maybe it affects the grounding???
I have a feeling it's for the power not the amp operation?