2 mics in phase

I'm going to use an SM57 and a ribbon mic to record guitar  (SM57 up close to the cab, the ribbon about 3' away).   Someone told me to make sure they're in phase.    Stupid questiion, but, How do I put them in phase??

You just set them both up during the recording phase and record their signals onto two tracks. It is during the mix phase that you try to invert the phase of one of those tracks. The idea is to mix the two mics and maybe get a blend.

When you invert the phase of one of them then the sound will change. For the better or worse? Hard to tell but the two resultant sounds will be different. Decide which one works best for you.

With bass when you record though a DI and a MIC the phase thing will more often result in one of them sounding better. But with guitar it is more about one sound vs another.

Putting both of them the same distance away is a good starting point. Even when doing that you will still get a difference between the two options and you may still prefer the sound of one of them being out of phase. But you are only limited to one version of two mics being summed and that is when they are equal distance. You miss out on the million other options when they are not.

So here is the approach when they are not. Put one of them at a fixed distance from the speaker and make the other moveable. Try getting the guitarist to play and while you are in the control room, listen to what happens when an assistant moves the movable one in and out while you are summing the two in the control room. You need to do that twice as well with the second variation being one of them out of phase. You might hit a fantastic sweet spot where the two sound awesome together. They won't necessarily be the same distance from the speaker when this happens either. It is a form of EQ that sounds like nothing else and not even EQ can match it. You also need to be aware that the levels of these two mics (when being summed) also have a fairly big impact on the sound.

But this is a bit more complicated. Do the equal distant thing first. Don't just assume the two in phase signals are best. You must audition the out of phase version just in case. It opens up a bit of a can of worms the moment you use two mics on a guitar cab. If you are not sure use one mic instead!

Who says the best guitar sound is right in front. They say the tip of the flame is further out. So the idea of having one 3 feet away is actually a good one. I am assuming you are overdubbing this guitar and it is the only thing making sound in the room. In fact putting two mikes the same distance away is a bit of a waste of two mics. You are better off having one a very different distance to the other. Recording a guitar sound futher out is not the same as slipping multiple guitar tracks in time either. But that approach is good when the two mikes are equal distace, at least you can get some variation on the tones that result.

The main thing is experiment and do some tests first to find out.

Thanks!! 

Greg

Or save yourself a lot of grief and use one mic.

Well yeah, or just use 1 mic :-) I use 2 sometimes? One on the 12th fret, and one over the bridge? But I notice that they can be out of phase, even in that close grouping? I may try just using 1...

A lot of guitarists use 2 mics when recording  (a guitar cab).  I heard a song by a friend, and his guitar tone was really nice.  I asked him about mic'ing his guitars, and he said he used his SM57 and a ribbon mic.   But he said to make sure they're in phase. 

So I'm going to try recording my guitar that way.   I just didn't understand about the mics being in phase.  

Thanks!!!  I appreciate all your input!!

Greg

Good to know, Steve.  Thanks!

Skull ...  Yes that's probably the quickest and simplest solution and probably the easiest to implement for the performance.  I suppose if further refinement is needed, then modest movement of the second mic wav could be performed as well.

Or pay for a good guitar track from one of the pros here? Just sayin... There are a lot of people with a lot of talent... (I'm not counting myself among them). 

I think you either have the mics the same distance or the second mic 3x the distance of the closer mic and it wont be out of phase but 2x distance will be out of phase... don't ask me why, I don't know... somehow I just learned it along the way.

J