Recording acoustic guitar is a challenge, to be sure. The sound hole can really put out some lows that can be uneven when compared to a live in-person experience.

Having the mic back is fine, although at 3 feet you're getting room sound as well, and a less immediate version of the guitar. If the room acoustics are good, that's ok. Try a foot instead, aimed between the soundhole and the end of the guitar where the neck is joined. If you want more lows, just twist the mic more toward the sound hole (or don't twist it and just add some eq).

For stereo I've often used the X-Y technique, with two 451's or C501E's about a foot back - crossed in an X shape (the barrels of the mics at 90 degrees crossed at the center) - one pointing toward the mid-neck, the other pointed midway between the sound hole and the end of the guitar. That avoids the direct lows projected by the sound hole, gets the warmth of the large portion of the body of the guitar and the clarity of the neck/string area. You can vary the distance from the guitar and vary the position of the point where the mics X intersect. Try the capsules closer together, farther apart, just experiment. I've also used C12's with the capsules roughly in the same position.

Another method you can try is one of the very earliest stereo methods called the Mid-Side Encoded technique. For guitar, have two mics positioned so the capsules are one above the other. Mic 1 should be set on cardioid aimed at the guitar. Mic 2 should be in a figure-8 aimed with the front of the mic pointed 90 degrees off Mic 1... basically looking left-right from the guitar.

The encoding can happen as you track to tape, or at mixdown time. To track the encoding to the multitrack, take your center cardioid mic on one fader assigned to the center of two busses, say 9 and 10. Next, take the figure-8 mic to a mult (a patchbay's version of a y-chord) and bring it's signal up on two faders, one bussed to 9, one to 10. Put the fader assigned to buss 10 out of phase. You can now control the stereo image by varying the level of the figure-8 faders. Remember to monitor the signal coming back from your multitrack - don't send these faders to your mix buss. The advantage to tracking your image to tape is that it saves a channel fader at mixdown time, but you are stuck with how wide the image can go at that point.

The other way to handle the encoding is to just record each mic to a separate channel on the multitrack. Then in mixdown, do what I described above. This gives you the flexibility of modifying the image as much or as little as you like within the context of your mix. It just takes up one more fader. If you don't have a mult in your patch bay, just pan the figure-8 to the left, assign it to an unused buss (or aux send), bring the output of that buss (or aux) into another fader out-of-phase panned right.

When using stereo miking, always check your sound in mono (usually a button on the console monitor section) to make sure that the sound is still good. If the mics have a phase problem, the mono sound will either sound way to soft or have some mid-rangey tone that is too different from the stereo sound. Move the mics till you have good sounds in both stereo and mono. Same thing with acoustic piano!

I have been known to compress acoustic guitar often, but it really depends on the instrument, the player, the placement of the mics, the kind of music that's being recorded, etc. If you're using Pro Tools or such, try to get the sound the way you want it from the get-go so that you do the minimum amount of processing in the computer. The recalculations in computer processors tampers with the coherency of the original sound, and dimensional qualities can suffer if a lot of number-crunching is going on there.

Q) My dad was talking about phase cancellation if I [used multiple mics]. Any idea on how phase cancellation might come into play with that technique? -Joe

Phase cancellation definitely plays a part. Use that mono button on your console to find out what's happening and what's not happening. Often when I would use back mics in conjunction with front mics, the resulting phase cancellation sounded very cool! It can be used to make a lot of variations in the sound, kinda like Queen did many years ago.

However, if you have an out -of-phase and in-phase mic panned hard left and hard right, there will be some stuff that goes whacky with radio station phase correction - and if you press vinyl it can be a big problem. If your phased tracks go to a TV show, the cancellation could cause your guitars to partially disappear or sound in a way you weren't expecting.

© Copyright 2000 - 2010 Vestman Mastering
Created 6/10/00 Modified 3/22/03
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