Vincent88

Hi, i'm Vincent i'm working at a simple progect wich must to acquire a signal from a microphone with the NI DAQPAD 6015. In Labwiev i had built a procedure that filters and amplifies the signal acquired. My problem is that when i go to do the fast fourier transformate i notice the noise at the high frequencies that are stronger than the signal acquired, i notice the noise also when i go to listen the file in wich i had save my acquisition.I had already take some precautions, like to shield wire and microphone utilizing a Faraday's cage but, although the noise is smaller than before, it's still too bigger than the signal. Other information: samples frequency: 44100 acquisition tipe: continuos samples to read: 250000 Anybody have any idea about this problem? Thanks for the answer