Electret microphone for acoustic guitars

[Guilherme]

I also hate piezos.

But the mic can be more prone to feedback than the piezo.

I use something like this:

http://www.google.com/patents/pdf/Sound ... nrGirEoUFg





The simplest schematic:



You can use the cap value to tame the bass.

1) You pick a cube of foam, slightly deeper than the guitar body and a little wider than the soundhole;

2) Draw two concentric circles, one of the soundhole diameter, the other a little wider.



3) With a knife or scissors, cut the foam making a ring.



4) Attach the mic to the foam. The foam serves as a mic mount.



5) Stuff it inside the guitar, through the sound hole. The mic wire can pass through the soundhole if you don't want to drill the guitar for a jack. You can rotate the ring to change mic position.



Good sound and reasonable feedback rejection (the foam insulates the mic from "external" sound and also dampens the soundboard just a little - that is good when amplifying guitars).

You can use a "generic" no brand electret mic, a "skype" mic or a lapel mic. The panasonic electret mics are considered very good.


Another option, using an electret mic:

1) get a small wooden block (pine) 2cm x 2 cm x 4 cm
2) drill all the way at the center of the block with a small drill (enoufg for the mic wire).
3) Make the hole larger (enough for the mic), but only for half of the length of the block;
4) It looks like this:)

Code: Select all

 __________________
|		      ______|
|___________|
  ___________
|		     |______
|__________________|

5) put the mic inside the block and seal it with epoxy.
6) Sand the block and finish it with lacquer (optional, but looks good).
7) Glue it to the sound board with pickup adhesive or with double sided adhesive tape.



A poor man's AKG C411.

[asfastasdark]

5) Stuff it inside the guitar, through the sound hole. The mic wire can pass through the soundhole if you don't want to drill the guitar for a jack. You can rotate the ring to change mic position.

How would one stuff that inside a guitar, if the outer radius is larger than the sound hole itself?

[Bernardduur]

5) Stuff it inside the guitar, through the sound hole. The mic wire can pass through the soundhole if you don't want to drill the guitar for a jack. You can rotate the ring to change mic position.

How would one stuff that inside a guitar, if the outer radius is larger than the sound hole itself?

it's foam

[Bernardduur]

I also hate piezos.

But the mic can be more prone to feedback than the piezo.

I use something like this:

http://www.google.com/patents/pdf/Sound ... nrGirEoUFg





The simplest schematic:



You can use the cap value to tame the bass.

1) You pick a cube of foam, slightly deeper than the guitar body and a little wider than the soundhole;

2) Draw two concentric circles, one of the soundhole diameter, the other a little wider.



3) With a knife or scissors, cut the foam making a ring.



4) Attach the mic to the foam. The foam serves as a mic mount.



5) Stuff it inside the guitar, through the sound hole. The mic wire can pass through the soundhole if you don't want to drill the guitar for a jack. You can rotate the ring to change mic position.



Good sound and reasonable feedback rejection (the foam insulates the mic from "external" sound and also dampens the soundboard just a little - that is good when amplifying guitars).

You can use a "generic" no brand electret mic, a "skype" mic or a lapel mic. The panasonic electret mics are considered very good.


Another option, using an electret mic:

1) get a small wooden block (pine) 2cm x 2 cm x 4 cm
2) drill all the way at the center of the block with a small drill (enoufg for the mic wire).
3) Make the hole larger (enough for the mic), but only for half of the length of the block;
4) It looks like this:)

Code: Select all

 __________________
|		      ______|
|___________|
  ___________
|		     |______
|__________________|

5) put the mic inside the block and seal it with epoxy.
6) Sand the block and finish it with lacquer (optional, but looks good).
7) Glue it to the sound board with pickup adhesive or with double sided adhesive tape.



A poor man's AKG C411.

Thanks man!

That foam trick really did the trick! I'll try to post pics later

[sean k]

I made this instrument and as you can see it has a piezo pickup and an electret capsule. Two little preamps then summed into another then out. If you want the schematic I'll post it. Addition of High pass and some phase reversal would be a good idea. No tone controls though.

[sweerra]

How to hook up microphone to the speakers? I have a 2.1 altec lansing speakers. I want to attach a microphone to it so it can amp what ever i say to the mic, how can i do this?