How can I mod a head-set type microphone into a omnidirectional microphone to pick up many voices in a room.

The mic will be used to pick up audio from numerous people through out a living room, and transmitted streaming via an XBOX 360 controller.  I am also trying to use existing materials, in addition this will later be built into a true instructable.   Any pointers would be awesome, I even toyed with the idea of making it into a parabolic mike and pointing it at the ceiling to pick up sounds through out the room.  Currently the microphone has an area where the sound is obviously designed to be picked up only from the speakers mouth.  Good news is its easy to take the headset apart, its screwed rather then glued together.  The Bad news, all the wiring is ultra thin enamel coated, so very evil to solder, well for me anyhow.  I have included a picture of the actual headset.  The ear-phones will be redirected to amplified speakers and the 2.5mm jack has to remain to hook up to the controller.  This is not because it is some special jack, just trying to make it appear stock when I'm done.  Any help would be awesome, and credit will be given of course, thanks in advance. 

Picture of How can I mod a head-set type microphone into a omnidirectional microphone to pick up many voices in a room.
sort by: active | newest | oldest
frollard7 years ago
Most 'directional' mics are omni mics with a waveguide that transmits sound from a given direction directly to the sensor and other noise to BOTH sides of the mic at the same time -- the one directional sound gets picked up while the room noise gets picked up by both directions and cancels itself out. To make it pick up room noise simply take the plastic waveguide off, and it should automatically pick up lots more noise.
I was going to say something very similar but you beat me to it.
maxkracht7 years ago
Instead of taking the "plastic waveguide" off, you can simply cover the ports (vents) with a piece of tape. Turns any cardioid mic into an omni. Taking the plastic part off might make your mic less efficient.

If you want to get slightly technical, the ports are on your mic to adjust the phase relationship between the direct sound (front of the mic) and indirect sounds. Direct sound waves hit the front of the mic's diaphragm then bend around, through the ports, and hit the back of the diaphragm. If the mic is designed well, when the same wave hits the back of the diaphragm it will be 360 degrees out of phase and boost the signal. Indirect sounds also hit the front of the diaphragm, but when they hit the back of the diaphragm they are 180 degrees out of phase in comparison to the original wave and cancel... To get a lot less technical, the ports on a mic get rid of sounds from the rear. If those ports were covered, sound waves would diffract around the back of the mic and into the front.
iminthebathroom (author) 7 years ago
Hey thanks!, I have never used the question/answer section of instructables, so quickly answered! I took apart the microphone further and discovered a small puck shaped microphone that had been angled to receive incoming sound from vents in the tip of the housing. Thanks you both for responding, I'll be posting an instructable on the build within the next week or two.
Welcome to the answers section -- just a heads up that you must reply to a comment for it to show up to the author of that comment -- I would never have known you typed this if I wasn't checking on the reply from re-design. Don't forget to mark 'best answer' if that is the case.
iminthebathroom (author)  frollard7 years ago
Thanks again!