GETTING THE SOUND INTO YOUR MIC...
SOUNDS SIMPLE: The sound goes in, the sound comes out...
If you let it. I mention this as I've just done maintenance and minor surgery on a nice old SHURE 520 green bullet that came in with remarkably low output for a HI-Z mic. So... What gives? The Controlled-Magnetic elements are among the most rugged and rarely fail by degrees. Upon disassembling the mic the cause became clear: Not only had the cavity of the mic's shell been packed with cotton (helps cut down unwanted resonant frequencies), the space between the grill and the element had also been packed -to the degree that the cotton was not only impeding the soundwaves entering the mic's grill, but causing damping of the element's collector surface by being in direct contact with it, physically preventing its free movement. Thus, very limited sensitivity and output. Once the cotton batting was removed, the output level was back to normal.
The grill and silk or wire mesh over the element of a microphone is there to protect it from damage due to foreign materials coming into contact with it. What we don't want to do is impede the very thing it's there to collect: Soundwaves.
THIS WEEK'S TIP: By all means keep your mic's element healthy and protected, but know that overdoing it will demand a sonic toll... Questions?
Fritz,
Have you got any suggestions for cloth other than true Silk to use as replacement grill cloth?
Regards,
Loren
Thanks for checking-in, Loren. I've seen just about every thing used from burlap to denim patches from old Levi's (NOT recommended). Cotton is absorbent and will decay. Wool? Your mic would smell like a wet dog... A thin synthetic mesh of a material such as nylon will keep the particulates and droplets of moisture out of LORD MICROPHONE. What kinds of material? Commercial "POP" filters are fashioned from a fabric that has quite a bit in common with sheer nylon stockings or pantyhose. I'm not kidding! A good pair of these will keep you in grill cloth for the rest of your life!
Thanks Fritz, much appreciated!
You've heard of "sending the wrong message"? CRYSTAL ELEMENTS can do this... I recently had the occasion to work on a lovely original SHURE 707A, complete with its R7 crystal element. Upon extracting the R7 from the mic's grill, disconnecting it for testing, and fitting it with alligator clip-equipped test leads, I gave the element a succession of light tabs. BOOM BOOM BOOM went the amplified signal from the legendary crystal. Wow, sez I, this baby's got loads of output! And then, "Test test test..." Absolute silence. No output with the verbal test. Repeat procedures, same results. Huh...
Let this WEEKLY TIP be a warning: If you're shopping for vintage crystal elements or the mics that contain them, don't settle for a simple "tap test" to assure the element in question is operational. The Rochelle salt crystals within can develop fractures that will allow signal generated by impact to pass yet NOT possess the continuity to allow soundwaves to be collected and transmitted. Very deceiving...