reversing phase on microphones

[frosty55]

When using two mics on a snare, one from below, one pointing down, how do you reverse the phase on one of them?

[paulears]

It's now generally conceded that what you're describing is termed changing the polarity, not the phase (despite many mixers being labelled as 'phase' on the button and manual). The main reason is that this is more accurate - changing the phase would require a time delay rather than a straight polarity inversion.

 

I'm assuming your mixer doesn't have this button, so the simplest way to do the reversal of hot and cold is with an in-line adapter - a male to female XLR with the pin 2 and 3 connections swapped, or a short male to female cable with the same swapped connections.

[johndenim]

If you can drive a soldering iron, I would say the cheapest way is to undo one side of the XLR, and swap the hot and cold wires.

 

John Denim.

[Killyp]

What mixing desk do you have?

 

What's the application? Live music or recorded music?

[BoogieBear]

Buy an XLR3 Male to XLR3 Female adaptor, open it up and swap the connections on pins 2 and 3 on just one end (either will do) put it back together but remember to mark it up clearly (I wrap red PVC tape around mine) to remind you that this adaptor is for polarity change only!

 

Cheers

Anton

[Jivemaster]

I was told that BBC practise was yellow patch leeds were reversed. It's simply a 2-3 crossover in a short lead or adaptor. I'd do it near the mix desk so that you can attend to it during rehearsals if required.

[Killyp]

There's no need to start re-wiring leads etc... if your desk has polarity or phase switches on it, or if this is for recording.

[johndenim]

I would assume the desk does not have this feature, hence the question.

 

If you could tell us Frosty55 if it is for live sound or recording?

 

John Denim.

[PAforMusic]

A couple of people have asked about the application - I'm just curious to know why it matters in this case? Isn't snare sound just snare sound regardless of whether it's live sound or recorded? Sorry if I'm missing something obvious here. (I'm new to this forum so I hope I'm posting OK.)

[bruce]

If it's being recorded digitally, you can invert that channel in software.

[Killyp]

A couple of people have asked about the application - I'm just curious to know why it matters in this case? Isn't snare sound just snare sound regardless of whether it's live sound or recorded? Sorry if I'm missing something obvious here. (I'm new to this forum so I hope I'm posting OK.)

 

As Bruce ^ says. If recorded into software such as Logic or Cubase, it's simply a case of clicking a button as practically every bit of (decent) audio software from the last 10 years or so has supported polarity switching.

 

For live sound, even a lot of mixers nowadays still have no polarity switches on them (cough cough Behringer desks in general cough).

[gyro_gearloose]

Have a look at your desk. Phase/polarity inverting switches are usually near the top of each channel strip near the gain pot. If your desk has them, it will have a 'O' with a diagonal line though it.

[johndenim]

Like this, top left.

http://i35.photobucket.com/albums/d174/977stinkytinky/Fig6.jpg

I don't know if a small polarity reverse box is available anywhere?

Anyone?

[bruce]

I don't know if a small polarity reverse box is available anywhere?

You mean something like http://cpc.farnell.com/AV16485 ?

 

http://cpc.farnell.com/productimages/farnell/standard/AV1648607-40.jpg

Interestingly, the switchable ones (av16486) are cheaper than the fixed ones!

[peternewman]

The desk outputs might not last too long though . I'd have thought a trailing box or a lead would be a safer bet.