Shure SM57 with lost sensitivity

Question

I've got a Shure SM57 that appears to have lost a great deal of sensitivity. For the longest time I couldn't figure out the issue and was changing preamps, cables, gain staging, etc. But I recently was attempting to mic a source with the 57 and had the gain cranked and still hardly any input, then immediately (on the exact same cable and line) swapped the 57 for a 58 and was getting a hot input level.

So I can only assume the 57 is roasted. Is this a problem anyone else has experienced? Is it repairable? Shure charges nearly the cost of a used 57 to make a repair so I'm not doing that.

Thanks for any input (umm, no pun intended).

Answer 1

Yeah, that happens eventually. I've been working with SM57s in live and studio setups for 15 years. In particular the ones used in live setups, which are used both indoor and outdoor, wears faster.

I experience reduced gain, loss of low end and "dynamics". This is due to the membrane and edge hardening and dirt/corrosion in the coil hole. There is not much to do about this, except replacing the cartridge with a R57 Replacement Cartridge for Shure SM56 and SM57 Microphones (~$80).

If the mic is useless as is, you can try "massaging" the membrane by pushing the center gently and see if you can release some stuck dirt, but don't count on it (you need to remove the head/grill).

If you also experience reduced high end, you may get lucky by simply cleaning the grill and the membrane (carefully with a wet swab!).