I'm trying to test a DSP that I'm adding ADC's and DAC's to. I just want to test the noise floor and THD. I'm a total newbie and can't seem to find a good tutorial. I found a tutorial on testing amps, but it doesn't get into how I can (or if I can) remove interface noise from my readings . Can REW do it, or do I just do the math manually? I only have an internal sound card and don't anticipate doing more than 2 projects (my car and by house) and can't justify spending money on tst equipment.
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Testing a DSP with REW.
- Thread starter ClayR
- Start date
Keith_W
Major Contributor
If you want to test the noise floor and THD you will need an ADC that has a lower noise floor than the device you are testing. I don't think your PC internal sound card will cut it, those are notoriously bad and will likely show you its noise floor instead of the device you are testing. You need an E1DA, it is the most reasonably priced test equipment you can buy.
And yes, you can use REW. Use the generator to create the test tones and the RTA to look at the result.
And yes, you can use REW. Use the generator to create the test tones and the RTA to look at the result.
Can you describe your DSP more? If you are adding ADC / DACs I assume you have I2S I/O on the DSP?
If you really want to quantify DSP performance, you will want to avoid any AD-DA conversions if possible. An I2S-USB I/O device like a miniDSP USBstreamer or MCHstreamer may be of use, although unfortunately they can only act as clock master, which may be OK if your DSP can be clocked from an external source via I2S.
If you want to quantify ADC + DSP + DAC performance, I agree with @Keith_W, you need a high-performance ADC like the Cosmos ADC.
Michael
If you really want to quantify DSP performance, you will want to avoid any AD-DA conversions if possible. An I2S-USB I/O device like a miniDSP USBstreamer or MCHstreamer may be of use, although unfortunately they can only act as clock master, which may be OK if your DSP can be clocked from an external source via I2S.
If you want to quantify ADC + DSP + DAC performance, I agree with @Keith_W, you need a high-performance ADC like the Cosmos ADC.
Michael
