Fortunately the test between flac and PCM stream decode is very easy to do. It can be be done remotely, in another room and there is no indication on the Touch itself what the state is.
A predetermined random sequence can be devised (computer or real coin flip or whatever). The tester sends an email to the "changer person" who looks up the next state on the list and changes the setting in the server. After sending the email the tester waits one minute then starts listening again. There is no direct contact between the person changing the setting and the tester and its only one way, there is no communication at all between the person changing the setting and the test subject. The test subject gets to listen to whatever music desired for as long as wanted to make the decision. Then requests a change. (which may not actually be a change of course). It would be nice to make it completely automated. When the tester wants a change he/she runs a program which grabs the next state from a file (or computes it and saves the result) and sets the server over the net. There are several very nice things about this test, first its the same hardware for all tests, you don't have to switch between devices. The change can be done remotely with no contact to the local device doing the playing. There is no indication of the state on the player. These get rid of a lot of traditional problems when trying to blind test audio equipment. I would like to design the test such that the tester gets to request either a or b or next random setting. Is there a problem from a protocol standpoint doing so? Particularly if the test is done over several days it would be nice to "refresh" the experience of a and b. Then the big question is how many tests to run. When others have done other tests and only done 8 or 10 tests they have been beaten up by some people saying that is way too small a number of tests, you need to do several hundred to be scientifically valid. Whats the score on that? Ten tests is not hard at all to do. 500 gets to be a little more difficult. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=71321 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
