THE BODY
The body is made of 1.125 OD diameter aluminum tubing. This diameter was picked to match the Switchcraft XLR plug.
You can look for someone local, or order it from a place like:
http://www.onlinemetals.com/merchant.cfm?pid=7537&step=4&showunits=inches
Purchase is by the foot, generally costing about 3.50 cents per foot. There might be a "cut" charge. I went to a local supplier here in Southern California and bought two feet in one shot.
The final microphone body will be about 110 mm long, so 1 ft is enough for several microphones.
I used aluminum. Others use copper water pipe, or other things. This is up to you. Consider that the body must also act as shielding, you don't want it to impart a sonic fingerprint of any sort, and it needs to be about a 1-inch diameter.
The grille material I used was 14x14 Brass wire mesh. You can go with a tighter mesh if you like, though make sure that the mesh itself is finer also. Again, think sonically first, esthetics second. There are also different types of metal. I liked the brass in contrast to the aluminum. The mesh also acts as a shield so it has to be metal. (just in case you had something plastic in mind)
Mesh can be purchased at http://www.mcmaster.com
Brass
Standard Grade Woven Wire Cloth 14 X 14 Mesh, .020" Wire Diameter,
12" X 12" Sheet
|
$9.38
|
The minimum size will be enough for many, many microphones. Like it or not.
In terms of the body, this is where people vary their plans.
I wanted to imitate a Neumann type look, hence the aluminum and the vents. Since the microphone is a cardioid microphone, sound has to hit the back of the capsule. This is why vents, holes, openings of some sort are in the sides of the microphone. Scott Helmke's "Alice" microphone actually has small windows cut out. Is it needed? Probably not, but it looks great and guarantees sonically unaltered sound getting to the back of the capsule.
If you don't put in vents, the pattern will be more Omni. However, since the capsule is a cardioid capsule, you run the risk of messing with your response curve.
The vents I cut initially were small, and I did notice a slight off axis coloration of the sound. Making them longer eliminated this problem.
Continue to building the Circuit
Is it worth anything yet?