Using a array of microphones

[xavigonzalvo]

I'm trying to acdquire signal from a 8 electret micros with a pci-6032e but I get 50Hz as well. Anyone knows how to connect one electret microphone to the pci to be free from 50hz. Thanks

[Filipe A.]

Hello;

Noise is a com;licated issue, regardless the situation.
There are some things you can try to overcome the problem though.
I'm attaching a good Applications Note you can refer to/ The App Note talks about some techniques that can be used to avoid noise.

Hope this helps.
Filipe A.
Applications Engineer
National Instruments

[Armando]

Well, I would recommend using a NI 4472 instead of the NI 6032. The NI 4472 is a 8 channels simultaneous acquisition board with a 24-bit sigma-delta convertor and 110+ dB dynamic range. It has signal conditioning on the board such as ICP, AC&DC coupling, anti-aliasing, etc. Several companies use it for microphone arrays because of the symultaneous acquisition with small phase mismatch and the very low noise front-end.