LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Taking a fft of a audio signal

I have no idea.  You will have to try to determine what the voltage range and bit resolution of the A/D that the mic input is using.
Randall Pursley
0 Kudos
Message 21 of 31
(1,061 Views)

Hi

 

I've been trying to write a program that takes in an audio signal and perform an FFT on it and display the FFT. I've been unsuccessful till now and I really need this program soon. Its a project in school. I am probably missing some knowledge that I don't have. I'm faily new to Labview. I have the updated program attached and if anyone has any idea on how to have an accurate FFT where the time domain is an frequency and the amplitude range changes to volts. I need to learn so please show me and explain.

 

Thanks in advance

 

Moe

0 Kudos
Message 22 of 31
(1,031 Views)

post your new program. As I said before. I feel I can not give you more help unless you show me some progress in your learning curve



Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)
0 Kudos
Message 23 of 31
(1,024 Views)
0 Kudos
Message 24 of 31
(1,007 Views)

You have done something but I am not sure it is a progress. And you have not paid attention to the sample frequency (or rate), or its reciprocal delta t. Here is a golden nugget for you. Always then I need to learn about how functions work in Labview I go help in the toolbar, and then find examples. I suggest you also start with this practice. Search for sound. I am quite sure they have an example reading continuous sound.



Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)
0 Kudos
Message 25 of 31
(996 Views)

Hi t06afre

 

quick question. I'm trying to connect dynamic data to a cluster of 4 elements. Its from acquire sounds vi to signal generation vi. Is there any way of doing that?

Thanks

0 Kudos
Message 26 of 31
(979 Views)

Hi,

 

Your VI already takes an FFT of the audio signal, but then passes the resulting frequency domain data into several VIs which operate on the time domain.  This will probably yield some interesting results at best.  You really only need the Spectral Measurements.  You might also want to scale the audio data to volts before passing it in to the FFT function, as was suggested earlier in this thread.  Also, you do not need the while loop, as it stands it will just keep performing the FFT on the same set of data.

Regards,

Jeremy_B

Applications Engineer
National Instruments
0 Kudos
Message 27 of 31
(970 Views)

Hi Jeremy

 

Thanks for replying. How would I scale the audio data to volts?

 

Thanks in advance

0 Kudos
Message 28 of 31
(966 Views)

Hi,

 

Randall Pursley explained how to do it on page 2 of this thread.

Regards,

Jeremy_B

Applications Engineer
National Instruments
0 Kudos
Message 29 of 31
(953 Views)

Hi Jeremy

 

I read it but I don't really understand how to interprete that in labview. All I see are Vi to adjust the time domain but nothing for volts.

 

 

thanks

0 Kudos
Message 30 of 31
(941 Views)