10db pad on mic

[RAMI]

I've read a few explanations, but it's still not clear to me.

If I engage the pad on a condensor mic, is it decreasing the signal going into the mic? Or is it decreasing the output of the mic going into the pre-amp?

I ask because I have a few spots on a drum track where a hard hit on the snare gave me a slight "crisp" sound that sounded like distortion. But nothing shows any clipping or peaking. It's coming from the overheads, not the 57 on the snare. So, did I overload the input on the mic, and will a pad help that?

 

[Chili]

I'm no electronics expert, but I would think the -10db pad lowers a bias voltage to the amp inside it so the signal going out the mic to the mic pre will be lower.

What are you using for o/h's? Most condensor mics can handle a high spl, probably higher than your ears can. And if they are o/h's, then they aren't directly next to a source. I doubt you're overloading the mic with a snare hit, not from 3 feet away. Your ears would hurt before the mic maxed out.

You have to be sure it is clipping. The noise could be something else. something in the room.. mic stand.... drum kit... neighbors....

Maybe the mic pre is clipping, even with the pad engaged, if your snare hit was loud enough, it could go over the 10db buffer the switch provides.

idk, just some thoughts.

 

[mshilarious]

Most often, a mic's pad is a capacitor switched into the circuit before the capsule FET, such that it directly loads (and therefore pads) the capsule. The signal received by the FET, and therefore the rest of the mic's circuit, is attenuated. This does result in a degradation of the mic's signal to noise ratio, as the FET's noise is unchanged.

Thus, ideally you shouldn't use a mic's internal pad unless the mic's internal circuitry is overloading. Otherwise, it's better to use the pad on the preamp, or an inline pad.

That said, in any such event the signal level is likely high enough that you don't care about noise. Just don't leave the pad on for all sources, as I have seen a few poor souls claim to do . . .

 

[John Willett]

Most often, a mic's pad is a capacitor switched into the circuit before the capsule FET, such that it directly loads (and therefore pads) the capsule. The signal received by the FET, and therefore the rest of the mic's circuit, is attenuated. This does result in a degradation of the mic's signal to noise ratio, as the FET's noise is unchanged.

Thus, ideally you shouldn't use a mic's internal pad unless the mic's internal circuitry is overloading. Otherwise, it's better to use the pad on the preamp, or an inline pad.

That said, in any such event the signal level is likely high enough that you don't care about noise. Just don't leave the pad on for all sources, as I have seen a few poor souls claim to do . . .

This is correct - the pad comes after the capsule and before the microphone's internal amp to prevent clipping.

Yes, it does affect the s/n ratio, so only use it when you have to.

 

[RAMI]

OK, thanx guiys, makes sense.. Chili, you're probably right. I'm most likely not overloading anything, but I have to figure out where that little clipping type sound is coming from. Maybe I'll post a clip when I get home from work.

Yes, it does affect the s/n ratio,

Does it? I can't understand how that would happen. Doesn't a pad just turn down the signal, which would reduce signal and noise equally? I'm not challenging you on it, I'm just asking.

 

[mshilarious]

Does it? I can't understand how that would happen. Doesn't a pad just turn down the signal, which would reduce signal and noise equally? I'm not challenging you on it, I'm just asking.

Because both the capsule and the FET have noise (and the rest of the circuit, but that's normally quieter than the capsule + FET). The pad reduces the capsule's noise along with its signal, but it can't reduce the FET's noise because it comes before it.

If you put a pad after the mic, then you reduce all noise sources together with signal, but that can't prevent the mic's circuitry from overloading.

 

[RAMI]

Thanx Chili, Ms, and John. I get it now.

Here's a 2 second clip of what I'm talking about. The flam on the snare seems to have a crackle (I think more out of the left side), but it might not be clipping. I'm hearing SOMETHING, though.

 

[mixsit]

The hit on the two before the crunch is a fairly strong hit, but clean. The distortion is umm, of the rather abrupt' type.
Makes me ask- is it a one time thing, usually you can see stuff this far out of whack in the editor.. (you in a prog? ..I'm thinking -this is too far out of wack to be mic clip.