Micing an acoustic w/mag pickup - phase?

[curbucci]

Going to mic an acoustic for live performance with a magnetic pickup with a EV N/D967. Will this cause any phasing issues if mic'd aprox. 3" away? Will I need to put the mic or mag out of phase?

[j3ffr0]

Hard to tell. If it was me I would want a phase switch handy for at one or the other.

[Doug Young]

Originally Posted by curbucci

Going to mic an acoustic for live performance with a magnetic pickup with a EV N/D967. Will this cause any phasing issues if mic'd aprox. 3" away? Will I need to put the mic or mag out of phase?

Any time you send two signals from separate sources, there's a chance of some phase differences. Those differences may sound good or bad. When in doubt, you can flip the polarity and see which way sounds better. For recording in a studio, it's common to use not just polarity, but a gizmo that can actually alter phase at a finer grained level than just polarity (which is what most "phase" switches do). Look at Little Labs IBP) when combining pickups and mics (or you can do it in the DAW). For live use, this is probably overkill for most people. Just plug in the guitar, put a mic in front of it, and let the sound person set levels, EQ, etc to taste. They might move the mic to dial in the "best" sound, in which case, phase may be one of the things that is being affected, but most likely no one will be thinking about phase, just what sounds good.

In my opinion, many of us worry too much about phase. In some cases, it can cause negative effects, especially when recording, but more often, it's just a fact of life. Our ears use phase to help us determine location, and phase is part of what creates a stereo sound. Play a note, and the top of the guitar vibrates in ways that are out of phase with each other, that's part of what makes an acoustic sound acoustic.

So, long winded way of saying "try it and see if you like it" :-)

[Cochese]

If youre running dual source and stereo try panning the mic to the left and the mag to the right. Phase issues are more prominent in mono. When recording i also run my main mix in stereo to check for any phase issues. As Doug said just try it. You will easily hear if its a problem as your sound will thin out

Another wat to fix it is with a digitsl delay on one source set to 100% wet. Usually just a dhort time delay 2-5 ms will correct it.

[Doug Young]

Originally Posted by Cochese

If youre running dual source and stereo try panning the mic to the left and the mag to the right. Phase issues are more prominent in mono. When recording i also run my main mix in stereo to check for any phase issues. As Doug said just try it. You will easily hear if its a problem as your sound will thin out

Another wat to fix it is with a digitsl delay on one source set to 100% wet. Usually just a dhort time delay 2-5 ms will correct it.

Panning hard left and right, of course, means part of the audience will hear the mic, part will hear the pickup - probably not what you want. You could try partial panning, but that still means each side of your audience hears something different. The big problem with any kind of delay is that phase is frequency-dependent. The amount of time to correct out of phase at 1KHz is twice what it takes to correct 2 Khz. So basically, you can correct precisely one frequency. Even the phase adjustment boxes, like IBP or Radial's Phazer are a compromise that let you choose the frequency that is most affected.

Honestly, blending in a mic generally improves almost any pickup, and unless you do something really wonky, phase is unlikely to be an issue. I have seen phase be a bit of an issue with dual pickups (not mics), but generally, pickups and mics are so different, that for live use they don't usually cause an issue. There are also so many things you can do to get a sound you like. Maybe you want mostly the sound of the pickup, with just a bit of mic for "air". Or you may find the mic alone sounds great, and you can bring in just a touch of the mag, maybe with all the highs rolled off, to get rid of the electric sound, to give you some low end punch. And so on. You should be able to just "try things" and find a spot for the mic, and a mix/EQ that you like.

[buzzardwhiskey]

I play with a Martin CEO7 with DiMarzio Black Angel mag pickup and a Shure Beta 57a mixed by a Zoom A3. Here are some examples...

A plectrum strummed tune called "The House That Never Was" https://www.youtube.com/watch?v=AW-rQKZey8c&

A fingerpicked tune called "Let Me Lift Your Burden" https://www.youtube.com/watch?v=j7P7MwFjbgY&

I've heard "phase" type issues, but they're just not much of a concern in most situations. In my opinion, two mics can make things a lot weirder than a mag and mic.

[Mad Rose]

Still working on my setup w/ the addition of a Mic. After playing through my old Fender Amps w/ K&K minis & being completely dissatisfied w/ the sound, I finally bought an acoustic amp (Fishman LB Artist). Putting the K&K into an XLR Preamp was a big improvement. Yet still, it wasn't what I wanted to hear. That pure acoustic tone was still missing, esp when hitting the strings hard.

After researching all week on different mics, forums & YT vids, a Shure SM-81 arrived yesterday. Hooking it up...a vast improvement. I don't have too much savy on micing, impedance, phasing, phantom pwr & such, so I'm still figuring out what the favorable settings, distances, etc are for my setup. I can say, I'm believe I'm heading in a much better direction than previously. After listening to what I've got now, adding an another mic will bring me even closer...?

With the resources available here & on the UMGF a lot can be gleaned. :>)

[guitaniac]

With respect to the Zoom A3 which Buzzardwhiskey mentioned in a previous post, it has two inputs (one for a pickup and one for a mic) and it actually has a phase reversal function for the mic channel. (Its common to try both phase positions to see which provides the most pleasing blend.) The mic signal can also be routed so that it doesn't blend with the mag signal until after the mag signal has been routed through EQ and/or other effects.

The Zoom A3 has a lot of functions and effects which require some study to use effectively. If you can get beyond that, however, its a pretty handy device for blending a pickup signal and a mic signal.