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1. is this response standard of most soundcards? the +/-3dB after 200Hz seems wrong.
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No, you have a problem. I would say your levels were incorrect for the test. Play around with the input output levels until the graph doesn't oscillate like that.
Here's my soundcard graph using the same scale axis as you used.
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2. after i save this as a .cal file and it automatically loads when I run the measurement again shouldn't the graph then be flat?
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What do you mean when you say run the measurement again. Running the soundcard measurement again will only produce another soundcard measurement file.
But, if you have a proper soundcard file it will make response measurements accurate because the results will remove the response anomolies caused by the soundcard. If you want to see that this system is working, you can take a normal sweep measurement of the piece of cable shorting line-in to line-out. It should be flat.
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Was hoping to use it to test S/N ratio
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Mmm, I don't really see how you could do this?
brucek