schiller wrote:Whether or not such unwanted sounds get captured along with the wanted sig may have to do with your sound card settings.
For the recording input there is (at least on some sound cards) a "channel" named "What I hear" and it seems you are recording that one instead of directly the output of the playback channel.
But this remains speculation until I ever find a decent block diagram of the typical sound card play/record arrangement which I confessedly have not understood fully until this day.
Harald
Yes, there is a certain lack of clarity in the documention produced by most soundcard manufacturers and it isn't helped when they are use different terms for the same thing, eg on my system 'what I hear' is called 'stereo mix'.
For block diagrams, you might like go to
www.datasheetarchive.com and search for 'ac97 codec'. This will lead to the datasheets for the chips used on soundcards, most of which show an overall block diagram.