Remove Noise

[sound nt]

Hi,

Let me first explain my problem,

I have a data acquisition card, taking input at 22050 samples/sec.

But after every 9300 samples or 488 msec (approx.)(see attachment) some noise is coming, i.e. in 1 sec (22050 sam) the noise repeats itself twice.

I think the problem is with  hardware, that we trying to sort out.

but i have given the job to solve it with software.

With help of signal generator, i have given 100mV, 100Hz sine wave input, that i have recorded as wav file.

By reading the wav file you can see the signal and noise seperately, respective VI is attached.

Is there a method to remove it.

[muks]

What is the cable length you are using? Can you shorten it and try?

[sound nt]

Hi MUKS,

Thanks for quick reply,

The cable length is small , about 15 cm, then also i will try to shorten it.

[sound nt]

Hi again,

I am connecting the card through the USB port, so i tried by connecting the card directly through USB port, then also the noise exists.

Regards, 

sound nt

[Coq_Rouge]

The Labview sound system introduced in 8.x has some flaws that NI has ignored for a long time. I think your problem is in the recording part of your program. Can you post this code  

[sound nt]

Hi,

I didnt do much, just used the VI given in the Examples. (Sound input to file).

But i have some other programs which detect the card and take input then also the noise comes.

Cant there be any method to eleminate the noise.

Regards

[Coq_Rouge]

Have you done any changes to this example. If so please post it

[muks]

Can you give more details about the exact hardware that you are using?

[sound nt]

Hi,

Coq Rouge  : No i have not made any changes in the example.

 muks : I am using a audio ic which can take analog input and can sample at 44 ksps.

[Coq_Rouge]

You can try the modifications I have made. I used constants just to show the value. The Labview sound system may create errors then reading data more than once every second.