2 x SM57's stopped working

raybbj

Member
Hi Folks,

I recently had 2 x SM57s stop working. Not stop working completely. They sound hollow and lower volume, as if someone put on a low cut @ 500hz or something with the gain turned down slightly. I find it strange this happened to 2 mics at relatively the same time. My other 57s still work fine. I A, B, C'd them all on the same signal path to test them all.

In fairness, the 2 that failed were very old (over 30 years), so I just went out and bought new ones. I can always use more SHURE stickers anyways :) . They were my 2 original 57s I bought when I was 16 years old, but I don't see why they should fail. They never received any abuse or drum stick hits and rarely left my constant room temperature studio. The only thing I can think of is the diaphragms may have worn out somehow? Any ideas why this would have happened.

Regards,
Ray
 

RFR

Well-known member
Never heard of that happening. Two at the same time?
Hmmm. Afraid im not much help.
 
Long shot...Have you tested with a few different cables? I suppose if one side of the balanced signal got dropped things could get weird.
 

raybbj

Member
When I say "At the same time". I just mean I plugged the both in for a project and realized they both weren't working after using them both successfully for another project a couple of weeks previous.

Regarding different cables. I plug in one 57 and it doesn't work. I plug in a known good 57 and it works fine. My signal chain including cabling is fine.

I'm not asking if someone can fix the problem. I was more just curious if anyone had heard of this problem before with any mic with the problem I described above (as if someone put on a low cut @ 500hz or something, with the gain turned down slightly). No bass and less volume. ......tinny sounding.

Regards and thanks
 

jimmys69

MOODerator
It takes a hard hit to kill a 57. Like a wrecking ball to do it. But I have heard one sound like that when they do actually get killed.
 
When I say "At the same time". I just mean I plugged the both in for a project and realized they both weren't working after using them both successfully for another project a couple of weeks previous.

Regarding different cables. I plug in one 57 and it doesn't work. I plug in a known good 57 and it works fine. My signal chain including cabling is fine.

Ah, fair enough.

I'm not asking if someone can fix the problem. I was more just curious if anyone had heard of this problem before with any mic with the problem I described above (as if someone put on a low cut @ 500hz or something, with the gain turned down slightly). No bass and less volume. ......tinny sounding.

Regards and thanks

What you're describing sounds like obstructed coils or diaphragms.
AKG d12 (twelve) gets this a lot because the diaphragm is clamped, rather than glued, and can move over time or as a result of a hard thud.
If you've ever put pressure on one side of a hifi speaker cone, you'll probably have observed the same symptoms. It forces the coil to rub sacrificing LF output.

Potential causes include exposure to moisture causing corrosion, debris in there (somehow) or foam degrading/coming loose and putting pressure on the diaphragm.

Someone had a similar thing a while back and another member here suggested sucking the top of the mic....I'm not even joking.
Whatever was causing the obstruction, that was enough to remedy it! :eek:
 

jimmys69

MOODerator
Ah, fair enough.



What you're describing sounds like obstructed coils or diaphragms.
AKG d12 (twelve) gets this a lot because the diaphragm is clamped, rather than glued, and can move over time or as a result of a hard thud.
If you've ever put pressure on one side of a hifi speaker cone, you'll probably have observed the same symptoms. It forces the coil to rub sacrificing LF output.

Potential causes include exposure to moisture causing corrosion, debris in there (somehow) or foam degrading/coming loose and putting pressure on the diaphragm.

Someone had a similar thing a while back and another member here suggested sucking the top of the mic....I'm not even joking.
Whatever was causing the obstruction, that was enough to remedy it! :eek:

Great advice! And I remember that conversation! LOL at sucking on a mic and it working! :)
 

raybbj

Member
Someone had a similar thing a while back and another member here suggested sucking the top of the mic....I'm not even joking.
Whatever was causing the obstruction, that was enough to remedy it! :eek:

I'm gonna try this in a few mins. If it works, I'm gonna freak out. I'll let you know.
Thanks for the insight and advice.
 

raybbj

Member
Holly Crap it worked !!! Although sucking didn't work, but cupping my hand around the mic and blowing (with an air tight seal so all the air went into the diaphragm) worked !!!
I could have saved myself a couple of hundred bucks!! Oh well Can never have enough 57s around I guess.
Thanks for the tip. I'm new to this board so I will try to return the favour to some other folks and offer my advice where needed. :) :)
 

raybbj

Member
I should add that my mic locker is located right near a sliding glass door and it can get kinda moist and humid in that area during the winter. I get a bid of condensation on the bottom of the glass door, but not much. Maybe that's what caused it. But they are stored in SHURE bags in a wooden drawer. I wouldn't think it got too humid in there. I have 12 guitars in the same room and they all stay in tune for the most part and only my Stingray bass requires a t-rod adjustment twice a year.

Anyhoo, Super happy right now. !!
 

miroslav

Cosmic Cowboy
Back in band days...we used 57s and 58s a lot on stage...and the ones that were used for vocals would get so full of crud (it was gross), everyone made sure they always got the same mic...:D...but at some point they just needed to be cleaned.
Not to mention, some of those band days were before smoking prohibition in clubs...so yeah, nasty cigarette shit would be on everything.

You may want to clean them up a bit more effectively than just blowing into them...maybe you knocked same crud loose, and it's OK for now, but then it causes issues again.
 
I suppose there's a good enough chance that there's corrosion on the coils and blowing/sucking was enough to free it.
Ideal? Not so much...but it worked! :)
 

miroslav

Cosmic Cowboy
They say you can hammer nails with a 57....maybe next time try that...it should definitely loosen the coil. :p
 

raybbj

Member
You may want to clean them up a bit more effectively than just blowing into them...maybe you knocked same crud loose, and it's OK for now, but then it causes issues again.

There shouldn't be any crud in them. They have never been used for vocals, only drums and amps and instruments. When I A/B them against my new 57s I just bought, they sound exactly the same now. I'll stick with the suck and blow method until it doesn't work anymore, then I'll take the caps off if need be to see what's going on under there.
 

ashcat_lt

Well-known member
Beyond the suck/blow method, how would one go about cleaning the things? I've got a couple of dynamics with a similar issue, and sucking didn't work. Believe me, I suck pretty hard ;). I guess I didn't try blowing, but I agree that this is likely only a temporary fix.

Also, I'm really surprised this thread has stayed this clean for this long...
 
Beyond the suck/blow method, how would one go about cleaning the things? I've got a couple of dynamics with a similar issue, and sucking didn't work. Believe me, I suck pretty hard ;). I guess I didn't try blowing, but I agree that this is likely only a temporary fix.

Also, I'm really surprised this thread has stayed this clean for this long...

LOL...

On the d12 the coil wires come out the sides of the diaphragm and are soldered onto trailing wires on the outside of the assembly,
so you can desolder at that point, remove the diaphragm clamps (no glue), and lift the whole diaphragm/coil away.

On the sm57 the diaphragm is glued down and and there's a lot more footery case removal to do in order to free the coil wires.

If the glue has given up and allowed the diaphragm to move the I suppose it's a relatively easy fix, but if the glue is good and there's crap in around the coil gap, I wouldn't fancy it.

If you did a successful tear down, I guess I'd clean the coil with a dry cotton swab and the gap with a piece of folded sticky tape, if there's visible debris.
 

RFR

Well-known member
I had a rehearsal studio once shitloads of 57s and 58s.Needed to ckean those suckers all the time. Used rubbing alcohol. A Lot! That and a toothbrush.
 
Beyond the suck/blow method, how would one go about cleaning the things? I've got a couple of dynamics with a similar issue, and sucking didn't work. Believe me, I suck pretty hard ;).

Jokes aside, I hesitate to recommend it.
Sure, applied gently it might prove a point and maybe fix the mic but I imagine it'd be easy enough to go too far and damage, or unseat, the diaphragm.
If the coil wires get torn or damaged, you're pretty much stuffed.
 

raybbj

Member
I agree, I didn't blow too hard, not like I was blowing up a balloon and busting my lungs. I just cupped my hand around it and blew gently, just enough to get the diaphragm moving more than just singing into it.
 
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