Topic: Speaker grille material on the face of the microphone?

[Rairun]

I bought a pair of CA-11 mics recently, and found the original owner had glued some speaker grille material on the face of the microphones:



He didn't seem to think it was be a problem, and I agreed, since this type of material tends to be acoustically transparent. But today someone told me "it will ruin the sound of the mics". Can anyone think of any reason why that would be the case? Should I just pull it off? I don't want to have to do it because it does make the mics a lot more inconspicuous. But if it reduces sound quality, I will have to.

[Rairun]

Oh, yeah, the hole pattern is definitely there underneath the fabric. The question is whether the fabric will degrade the sound quality or not. Probably not? If it doesn't, I don't want to remove it.

[Gutbucket]

Yeah, it will be more important to pull the capsule out of the croakie enough so that the side vents of the capsule are not obscured.   Best to have the same speaker grill cloth covering both the front and the side vents, or nothing covering either.

As Jon notes, if audible at all, the change in timbre from the presence of the thin speaker cloth will be a slight high frequent cut.  That can be easily offset by EQ, and the amount needed to do that will usually be significantly less than what you'd use to correct for best subjective response in the final recording anyway.

In that regard, its probably similar to mounting the mics underneath a thin shirt.

[MIQ]

If your stealth mics are cardioid, then you are absolutely changing the polar response of the mics and probably not a manner you expect...

If the croakie mics are omnis, no worries.

Very true, and sticking your head between the mics is going to change the polar response of the mics too, including the omnis.  Shooting for some form of HRTF is never going to be like a near coincident unbaffled mic set up.

Not saying you should hinder or not insure the proper functioning of the directional mics by letting the rear vents get covered with material, but using mics on croakies will result in their polar patterns getting altered by your head, hopefully in a useful way. 

[Gutbucket]

Very true, however the effect of adding additional acoustic resistance to the vents by covering them with the croakies is less predicable, and likely leads to less desirable pattern changes than the intentional baffling effect of mounting the mics on either side of your head.

[MIQ]

No doubt.   

[Rairun]

Thanks all. That was very informative. For now, I've wrapped some foam around the cable at the base of the mic so that it sits snugly within the croakies, even when the capsule is completely out. Now the side holes aren't blocked at all. The front ones are still blocked by the speaker grille cloth, but I think I'm going to test it first before I consider removing it.

Here's a recording I made in my living room before I did any of that. I start out with the CA-11s plugged straight into a Zoom H1, and then halfway through I switch to the recorder's internal mics. The CA-11s had the speaker grille cloth on, and were also completely within the croakies. The Zoom H1 mics were covered by a regular windscreen. Both were sitting about 3 meters away from the speakers.

https://www.sendspace.com/file/oj6sqb

[spybo]

FYI Mat
Material is speaker grille material by KRIX speakers....a local speaker brand here in Oz who have many speakers in theatres and the Festival Th. which has amazing acoustics.
In stealth situations "less is more" so the blackness helps...I never had the mics stick out from the croakies....pointless for the loud shows imho....and for many "ears" a non-issue....live environments do not always give the clarity we tapers need and in Stealth mode less so....the crowd is usually the biggest hindrance with noise....having said that I've always used croakies and pulled many great recordings with those cards.
I'll expect you will be surprised how well they go...use the low gain on the 9000 and halfway on the knob....adjust you zoom accordingly.( I didn't put material on the side vents as they were inside the craokies.....)