Phase reverse?

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brokenwindow

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I read a few tips for recording guitar using phase reverse. Can someone explain what phase reverse is? And if the Roland vs-880 has this feature?(I posted this in the roland forum with no replies)...thanks
 
As far as I know, the 880 has nothing for phase reversal. I have used it for a few years and haven't come across anything.

As to exactly what it is, I'll leave it to the experts here. However, in recording I think it has something to do with what can happen if you have two mics recording a single source, and because of the differences in time it takes for the sound to get to the mics, the sound can be out of phase and some parts of the two waveforms can actually cancel each other out. If you reverse the phase on one of the signals, then you could eliminate this problem. Phase and phase reversal can apply to several other things such as motors, but that's the general idea I have of it. Of course, I could be totally wrong on both counts.

[This message has been edited by Jon X (edited 05-21-2000).]
 
That's pretty much it. You can make your own cable and have it wired internally reversed. Switch pin 2 and 3 on one end. Or , (I used the VS880 for 2 years and now the VS1680) I also use an external mic pre amp. I'm not impressed with the ones even on the 1680. Most pre amps come with phase reversal. The reasons you want are pretty much what Jon X said. An example may be a dual mic setup on a n acoustic guitar. You can also get some neat phantom stereo stuuf, (not phantom power) where the sound is deep and hard to place but 3 dimensional to your ears.
 
You could also use phase reversal to your advantage to record two different sources with one mic in Figure-8 pattern. Say you want to record two singers signing at the same time, but only have ONE mic and want to have isolated signals on each of them. Set your mic to Figure-8 pattern, have the singers stand facing each other and put the mic between them so that one of the "live" lobes of the mic faces each singer. Then double the signal at the mixer (with either a "y" xlr cable or by a direct out from one channel to the input of another channel). Reverse the phase on one of the signals and you'll have two separate signals... that is, each singer will be on their own channel and you'll have separate control with just one mic.

There will be a little bleed on each mic, but if you're in a crunch and only have one mic (it has to have the Figure-8 pattern on it) and your singers need to sing together, then this is a creative way to use phase reversal to your advantage. Note: you'll have to have a mic that records Figure-8 pattern. Many budget mics do not have this feature (most budget mics, NT1, 4033, have only cardiod pattern). But there are a few mics in the $400 - $500 range that have multiple polar patterns. Many budget mixers do not have phase reversal switches or direct outs, but in the hard disk recording world many programs have this feature OR you could copy two versions of the signal and change the phase on one of them in a digital audio editor (Sound Forge, Cool Edit, etc...).

Rev E

[This message has been edited by Rev E (edited 05-22-2000).]

[This message has been edited by Rev E (edited 05-22-2000).]
 
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