how to use sound card to test THD?

[orlando111]

Hi,

I use the sound card to test a sina signal's THD(Distortion). But  I found the result is error and not rule.

Could you tell me how to use sound card to test THD? 

Attach my program.

Regards,

[orlando111]

nobody use it? please help!

[dsb@NI]

The VI you attached ran without error on my computer in LV 8.6.1. On your machine, verify that you are able to acquire data from a microphone through your sound card. If there are no errors from the Sound Input VIs, then the error is returned by the Distortion Measurements Express VI. Please provide more details on the error (code and source) so that we have a better idea of how to help.