Filtering noise with two mics?

[Aidan Prior]

Hey guys,

So I'm currently trying to record someone talking in an industrial factory which has a lot of background noise. I attempted to use a standard singing mic which recorded every little bit of noise in it heard.

I decided a shotgun mic was a far better idea but still fairly noisy. The main signal strength of some noises is at 396 Hz and 250 Hz so I plan to equalise these out but I am still left with a lot of background noise, just no strong signals. I thought what if I have an ambient mic recording all the noise from the factory and the shotgun mic recording the voice but also noise. Any noise that is present in both mics can be cancelled out.

My question is, how do you suggest I go about doing this? Any help on this is greatly appreciated.

Kind regards,
Aidan

 

[Chris Hindle]

Just like The Grateful Dead did for years.
2 identical mics, wired out of phase, to the same input on the board.
Hold the mic's fairly close to each other, but speak DIRECTLY in to one.
The "common" noises will cancel out, and leave the voice.
Depending on the mic, you will have to play with distance between them.
I saw one use of SM-57's taped together, with one capsule pointing towards the speaker, and the other 180º away.
It worked.
Chris.

 

[Weogo Reed]

Aidan, properly used, a differoid Crown CM311 would work well.

 

[Mike Caldwell]

What kind of mic tecnique do your people have? The old school two mics wired out of phase with a Y cable or a Crown differiod may help but as mentioned they will need to be on top of the mic.


For what it's worth I think the Dead used either EV RE 10's or 11's.

 

[Chris Hindle]

I thought they were either B&K or Neuman mics.
SDC if I remember.
Chris.

 

[Mike Caldwell]

I thought they were either B&K or Neuman mics.
SDC if I remember.
Chris.

Yep I just did some Googling and found the mention to B&K mics being used.
I could not find it now but somewhere I remember seeing what really looked liked EV Re's plugged
into the combiner boxes on the mic stands.

 

[Mike Caldwell]

Ok I just found some pics of various members of the Greatful Dead singing into single EV RE series mics, maybe my brain was melding the images I've seen together with the passing of time!

Still looking !!!

 

[Chris Hindle]

I seem to remember reading somewhere that they were on a hunt for matched pairs of microphones.
You're not getting that with any kind of conventional SR offering. Especially in the 70's.
Of course, the better the match, the better the rejection.
Chris.