Mic Phasing

[Murt]

Could someone please explain why I am experiencing mic phasing.

I have a vocal chain set up for tracking. Two mics next to each other about 50mm apart (2" in analogue speak) but same distance from the vocalists mouth (about 150mm or 6"). One is an Oktava MK219 (Russian mass production budget mic) going through an el cheapo Behringer mic pre and then through input 1 of the MBox2Pro, the other is an SE Electronics 2200A (another mass production budget mic) going through input 2 of the Mbox2Pro. So, both mics going to separate tracks and technically the vocal soundwave is reaching both mics at the same time. The waveform in the Edit window certainly looks like they match up. However, when I mute either mic on playback the other is quite loud and clear, but when I play both vocal tracks at the same time, the vox volume level
reduces dramatically, so I presume I am experiencing phasing, not that I have much experience of it to know. Does anyone have any clues or good tips on recording vocals through two different mics at once without the phasing?

[Top Jimmy]

Double-miking a singer is going to be fraught with trouble. I've never had one be so absolutely still that there wouldn't be phasing issues as they move around.

Test your mics to make sure that the sound is really arriving at the same time and is in the same polarity. Drop the tracks into record and hold a sheet of paper up where the singer's mouth would be. Flick the back of the paper with your finger just like you used to do to your brother's ear. Check in PT whether the major transient is in time and polarity.

[daeron80]

Yep, the phasing is caused by the mics being 2" apart. Doesn't matter how close or far the source is, if they're 2" apart and you're using them together, serious comb filter effects will result. It's a simple matter of acoustics.

If the mics are made in such a way that the capsules could be placed almost touching, that would reduce it, but wouldn't give you a stereo image to speak of unless they were placed far enough away to allow audible room reflections. Anyway, it would be a lousy stereo since the mics are different.

If you're looking for a wide stereo vocal, you might try using them in an M-S configuration if one of them has a figure-8 pattern. For any other stereo usage I can think of off hand, the mics would need to be identical.

[O.G. Killa]

Originally Posted by Murt

Could someone please explain why I am experiencing mic phasing.

I have a vocal chain set up for tracking. Two mics next to each other about 50mm apart (2" in analogue speak) but same distance from the vocalists mouth (about 150mm or 6"). One is an Oktava MK219 (Russian mass production budget mic) going through an el cheapo Behringer mic pre and then through input 1 of the MBox2Pro, the other is an SE Electronics 2200A (another mass production budget mic) going through input 2 of the Mbox2Pro. So, both mics going to separate tracks and technically the vocal soundwave is reaching both mics at the same time. The waveform in the Edit window certainly looks like they match up. However, when I mute either mic on playback the other is quite loud and clear, but when I play both vocal tracks at the same time, the vox volume level
reduces dramatically, so I presume I am experiencing phasing, not that I have much experience of it to know. Does anyone have any clues or good tips on recording vocals through two different mics at once without the phasing?

In addition to everything else, bypass the behringer mic pre and try the same setup using MBoxPro Inputs 1 and 2. Still having the same problem?

The Behringer could be flipping the polarity of the signal inside the preamp for some strange reason...you never know, weirder things have happened! LOL

[O.G. Killa]

Also check your mic cables... for example, Hosa cable is notorious for having shorts inside the connectors. I wouldn't be surprised if you found you had a cheap cable that was wired pin3 hot on one end.

With the less expensive gear, quality control is practically non-existent... so really anything could be flipping the polarity. Heck, even the wiring in the mic itself could be the culprit!

[Murt]

Thanks for the advice guys.

I suppose I should eliminate the mic pre from the equation first as OG suggested and then check cables, mic placement etc. My reason for using two different mics at the same time was to maybe use one for the verses and bring in the second on the choruses as an effect of sorts. I've done this in the past with an SM58 as one of the mics and it seemed to work.

[albee1952]

Here's an idea that no one else has hit on; record with both mics but MUTE one of the tracks. The trick here is to not listen to BOTH tracks at once(no phase issue this way). I had a session where the singer sounded great on a U87 in his low range, but not in his high range. The solution was to place a 414 directly above the U87 and record both(but only monitor 1). Then on mixdown, I muted the 414 for the verses and the U87 on the choruses. Worked like a charm.

Personally, I can't think of a good reason to USE both tracks at once, but once they are recorded, you could zoom way in to verify the 2 tracks are aligned and phase accurate. Nudge to fix mis-alignment, and use Audiosuite 1 band EQ to reverse the polarity(if needed).

[flommer]

Originally Posted by O.G. Killa

Also check your mic cables... for example, Hosa cable is notorious for having shorts inside the connectors. I wouldn't be surprised if you found you had a cheap cable that was wired pin3 hot on one end.

With the less expensive gear, quality control is practically non-existent... so really anything could be flipping the polarity. Heck, even the wiring in the mic itself could be the culprit!

If the polarity was wrong, it should be very obvious in the waveforms if you zoom in enough to see the individual peaks and troughs..


Do you have the mics side by side or one on top of the other? You might try the opposite of whatever you are doing now..

Also, really, how much of a difference is there going to be between the sound of those 2 mics that you couldn't achieve by just splitting the signal in protools and effecting one channel differently from the other.. I guess if you had 2 really different sounding mics with a bunch of MOJO...

[Murt]

Flommer, I take your point. There isn't much difference between the mics (which are side by side). I suppose I was just experimenting really. I could achieve a different effect in other ways, but it's fun to see if different things work or not.

Albee, I was thinking of this myself (not using both tracks at once) using the 'shift M' trick (highlight both vox tracks, mute one and then 'shift M' to compare on playback (regards to Kenny Gioia for that one) Also works with 'shift S' for solo of course.

Thanks again guys for the advice and feedback.

[Murt]

Originally Posted by albee1952

and use Audiosuite 1 band EQ to reverse the polarity(if needed).

For the record, just tried this and it works. Good tip.