Damaging Mics?

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Member Since: Nov 19, 2008


It might sound like a dumb question, but I am new to recording. Is it possible to damage a microphone when miking a very loud amp???

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Since: Nov 27, 2007

Nov 19, 2008 06:05 am

i've asked the same question before too.
Depends on what mic you have but generally they are fine.

if you are using a sm57 or sm58 there's pretty much no chance you'll kill them.
i think they can take up to 130db or something like that.

for condeners i think your fairly safe too.
some else will probably elaborate on this.
i use my rode nt1 on my amp and its fine.
i dont have it right up to the grill though.

I am not a crook's head
Since: Mar 14, 2003

Nov 19, 2008 11:22 am

An SM57 or SM58 have a very high SPL tolerance. You'd probably have to hang them out of the window of a jet liner to get those diaphragms to bottom out.

But with a lot of condensors, especially large diaphragm condensors, they are much more sensitive to sound pressure waves (which is why we all like them for detailed reproductions of sound sources). The diaphragm inside the microphone can only travel so far in each direction (positive and negative). Sometimes the diaphragm can move enough to actually "bottom out", where it makes contact with some of the internal components of the mic (I can't remember exactly which component...the plate maybe?).

I've even read that the wind produced by a door swinging open can be enough to damage some microphones.

It's all in the design. Look at the specs of your mics and see what their max SPL handling capability is. That should give you an idea of what it can withstand without damage.

The Czar of BS
Since: Dec 31, 2007

Nov 19, 2008 01:04 pm

Ribbon mics are the most sensitive to high SPL. Other then that, most modern mics, weather condenser, or dynamic, can handle pretty high SPL. I believe the average is around 120 dB to 136 dB. You should be fine close micing a cabinet without issue.

If your finding a lot of distortion when recording in this fashion, then you may need to pad the mic.

Since: Nov 19, 2008

Nov 19, 2008 09:10 pm

I was planning on buying a TASCAM US 144, and it comes with MXL 990 and 991. Since the price looks like a steal ($199) I was wondering if I would be able to use 990/991 mics on my amp without damaging them (which is a Behringer GMX212, 120 watt amp)?

I am not a crook's head
Since: Mar 14, 2003

Nov 19, 2008 09:46 pm

I find that my MXL 990 can't quite handle the SPL of a cranked amp. If you're recording REALLY loud, then it'll crackle and distort. I've been able to find a recording volume that's a compromise between what the amp can do versus what the mic can handle. Plus I back it up a few feet to ease the SPL plus get a bit more room ambience involved.

I don't have a 991, but I do have a matched pair of 993s, and I find that with their -10 dB pad, they can handle a cranked amp no problem. They just sound a little different than the 990 does. I actually prefer the 990 a few feet back combined with a Shure SM57 right up on the grille. I've always been happy with that combination.

MXL makes a version of the 990 that has a -10 dB pad and a low-end rolloff switch. It's only like $10 more and would be totally worth it if you ask me.

I see that the amp you're micing is a solid state 2x12. Since its solid state, you probably won't need to crank it very much to find its sweet spot. It's when you're dealing with a tube power section that you generally need to crank the master volume to get the power tubes cooking. With your solid-state power section, you'll just have to turn it up loud enough to get the speakers really moving so that they'll add their subtle breakup to your sound.

Since: Nov 19, 2008

Nov 19, 2008 09:58 pm

Thanx. I really appreciate the help :)

Since: Mar 12, 2008

Nov 19, 2008 10:37 pm

I second what tadpui said. I used the 990(without the -10 rolloff) recenty with a Marshall JVM 100 watt tube amp with a 4x12 cab (tons of gain) and had it back about 4-5 feet and i got a very nice sound. I also used a sm57 and e609 on the grill to get the rest of it. So they should be fine just dont throw em right up in front.

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