JohnSwenson;571850 Wrote: > I like the playlist concept, I just see one major problem, at least on > my system wav and flac show up differently on the screen of the Touch > and controller. In order for this to work they would have to display > exactly the same. Thats the reason I mentioned changing the server > streaming settings, it doesn't change the display in any way. > > Lets make sure I understand this: we have a wav and flac of the same > song. We have a playlist with a random distribution of those two songs. > The person performing the test can listen to the playlist as many times > as desired, skip forward, back etc. Now what should the output be? A > list of tracks and whether they are pcm or flac OR which ones are > prefered? Its seems to me that adding preference into it rather than > just flac or pcm is complicating the test.
I taking stats courses would come in useful one day! You'd need to set it up so that you can't see the difference on your touch screen or can't tell the difference in some other way. In theory the touch could be slower to respond to flac (or pcm) songs or some other random interface thing. I propose the following 3 formats. 1 is my original idea. 2 is the idea above and 3 is another format. I'm liking 3 as it most directly answers the basic question of whether you can hear a difference. FORMAT 1 As I originally proposed. N pairs of the same song/set of music. Identify the better. H0: pcm not better than flac streaming H1: pcm is better. Here you'd need to get enough of PCM as better to reject H0. E.g. 22 out of 30. FORMAT 2 A playlist of N entries with the same song repeated randomly flac or pcm. You just go through and specify which entry is flac and which is pcm. Before you start you can listen to known examples of the song in flac and pcm. H0 = you can't identify flac or pcm on that song; H1 = you can identify; Here you need to identify enough songs correctly to reject H0. E.g. 22 out of 30. You can listen to the whole list jump forward/back etc. If you can't tell the difference in the end it will just be still a 50% chance of getting it right on each song. This is a more specific result. The minor problem with this is that if you do not manage to do it they can still be different, you could just be bad at identifying them. This involves less tracks. I.e. only N. The other both involve 2*N. FORMAT 3 N pairs of songs. Each is a pair of the same track. But different pairs can be different tracks. Here we simply randomly flip pairs such that they are the same (both pcm or both flac) or different (1 pcm and 1 flac). You just identify which pairs are different and which are the same. H0: You cannot reliably tell which pairs are different and which not. H1: You can. Again identify enough of the pairs correctly as different or the same then we can reject H0. This is the best one in my mind. This specifically looks just at whether you can correctly identify when they are different . You don't need to identify them as flac or pcm or to pronounce one as better. Also we could use different tracks for each pair. MUSIC For all the below you should chose the music used as the hypothesis that is supported by the lossless is lossless camp is that you cannot tell the difference whatever the music. So you should use music where you think you can tell the difference. Obviously it would be nice for everyone if it covers a broad range of genres (another reason to like format 3 as it can be different music) but if you can only tell the difference on Kylie Mingogue's Locomotion then that is still a difference. :D -- lrossouw Louis 'Last.fm' (http://www.last.fm/user/lrossouw) ------------------------------------------------------------------------ lrossouw's Profile: http://forums.slimdevices.com/member.php?userid=3416 View this thread: http://forums.slimdevices.com/showthread.php?t=71321 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
