Awhile back, I wrote a post about building a ribbon mic. I completed the first one, with a completely custom fabricated shell and everything. It sounded pretty good, if I do say so myself, and I was quite pleased.
But I use the past tense for a reason. When I went to place the mic in its case, I noticed that my design is fatally flawed. The glue holding the magnets to the plexiglas frame has failed, bringing the two magnets together and obliterating the carefully placed ribbon. (it took three tries before I finally got it right… what a pain in the butt!)
So it’s pretty clear that the whole thing should be redesigned. I’ve learned a few things that should improve the performance anyway. The first and most obvious it my method for holding the magnets. I’d actually considered this before, but I need to include a small spacer to set the magnet gap. This way it’s physically impossible for the magnets to come together. An added benefit is that controlling the gap dimensions can be more precise, since the spacer determines the gap width rather than the frame.
Another design change for this version will be a metal frame rather than a plastic one. Metal (ferrous) provides a magnetic return path that can increase the output a few dB, and I need all I can get. It’s a little more difficult to machine, but I have the tools to do it, so why not?
It’ll be awhile before I can get to this, though. Every time I think of the hours put into the current mic, it really drains my energy and I hesitate. But I’ll start doing doodles on the backs of junk mail shortly, and I’ll get going on another design soon.