Acoustic guitar (4 questions and replies)

I've got my acoustic guitar already equipped with an undersaddle piezo transducer but I'm looking for a more natural, woody sound. Hearing about your Crown GLM-200 microphone, it seems to me that using the two sources and mixing them in a console would give better results.
Yves Geleff, French songwriter and country singer.

Reply: Yes, the sound will be more natural if you mix in a microphone. Here are two suggested GLM miking methods:
1. Using the supplied clip, mount a GLM-200 hypercardioid mic about 2 inches from where the fingerboard meets the guitar body.
2. Clip or tape a GLM-100 omni mic outside the guitar at the edge of the soundhole.

You will need two separate cables from your guitar: (1) one from the pickup to a direct box and from there to a mixer mic input, and (2) one from the GLM into a mixer mic input. Adjust EQ as needed.


I'm considering purchasing a Crown PCC-130 for recording myself playing solo classical guitar. The reason I was thinking of the PCC-130 is that it looks small enough to simply attach to the underside of my music stand remaining somewhat hidden but still of good quality.  

I am not a professional musician. I simply want to create a quality recording setup for listening to myself practice/play and for possible making CDs to give to my immediate family members. Can you give me your thoughts on the PCC-130, or another recommendation in a similar price range? Mark Westling  

Reply: The best-sounding Crown microphone for the acoustic guitar is the CM-700. It is a "stick" shaped microphone that mounts on a mic stand. Typical placement is about 8 to 12 inches from the 12th fret, aiming at the sound hole. The CM-700 costs about $30 more than the PCC-130.  

If the microphone must be hidden, the PCC-130 would be a good choice, but it has about 7 dB more noise (hiss) than the CM-700 when mounted as you described. Also, the PCC-130 frequency response is not as flat as the CM-700's frequency response, so the sound would not be quite as natural.  

Another choice is the GLM-100, a miniature omnidirectional mic which you could mount on the underside of your music stand, aiming at the guitar. Although it has about 7 dB more noise (hiss) than the CM-700, the GLM-100 has a very flat frequency response. Mic placement near the sound hole might sound a little too bassy but you can fix this with EQ on your mixer. The GLM-100 costs about $50 less than the PCC-130.  

If appearance is not a problem, you could tape the GLM-100 to the body of your guitar, about 1/2 inch from the low E string, and midway between the bridge and sound hole. This placement results in less noise (hiss) than placement on the music stand. Placement on the guitar also picks up less room acoustics and room noise.  

So for best sound, use the CM-700. To save money, use the GLM-100. Try both placements and see what works better for you.


I am recording a vocal and acoustic guitar into a DAT recorder. Will I need two mics? Which mics sound best for this application?

Reply: Here are some recommendations:

Vocal: Crown CM-200A aiming up at your mouth about 2 inches away. Be sure to put the foam windscreen on the mic to reduce breath pops. If this sounds too bassy, roll off the excess bass with your mixer (if you're using one).

Acoustic guitar: See the figure below. Try a Crown CM-700 aiming down at the spot midway between the sound hole and the point where the fingerboard joins the guitar body. If the guitar sounds too bassy, set the bass-tilt switch on the CM-700 to reduce the bass.

Another option for the acoustic guitar is to use a good pickup, or use a Crown GLM-100 miniature omni mic taped near the sound hole. Turn down the excess bass with your mixer if you use this method.


I'm recording a singing guitarist into my computer. I have a CM-200A on the vocal and a CM-700 on the guitar. The singer's voice sounds okay when I monitor just the vocal mic, but it sounds filtered or phasey when I mix in the guitar mic. What's going on?
Duane Livnel

Reply: The guitar mic is picking up some vocal leakage with a short delay. This causes phase interference (comb filtering or flanging) when the vocal mic and guitar mic are mixed to the same channel.

To get the vocal track in phase with its leakage on the guitar track, I've found this helpful:

1. Mix the two tracks at equal vocal levels (that is turn up the guitar track until the vocal leakage is as loud as the vocal track).
2. Reverse the polarity of the vocal track.
3. Nudge-delay the vocal track (slide it to the right) by less than a millisecond at a time until the vocal cancels out as much as possible. A 1 millisecond delay is typical.
4. Put the vocal track back in normal polarity. Set the guitar-track fader for a good mix. You should hear the vocal/guitar mix without much phase interference.

Other ways to reduce phase interference are:

*Mike closer
*Record the guitar first, then overdub the vocal if the performer is comfortable doing that.
*Use just one mic about 1 foot away. Raise and lower the mic until you monitor a good balance between voice and guitar. If the guitar is very quiet, the mic might end up near the bottom edge of the guitar, aiming at the singer.