| Allen the null tests do work. And you have to (you must) use the same audio files otherwise, like you mention, you bring in other variables such as soundcards etc.
So yes, the null tests are accurate for using the exact same audio files, and in fact that is the only proper way to test it.
Allen, in the tests where you heard differences, were they done as A/B tests or A/B/X? Because it is very easy to fool oneself into hearing differences where there are none with A/B tests. Throw in an X and see if you still hear the differences? If you can pass an A/B/X test with 100% then you can safely say you are hearing differences, otherwise A/B can be deceiving especially between identical audio files.
cheers.
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