Digital audio listening test

[Martin Czech]

I heard (propaganda) from the people that develop mpeg code
that pulses are a pain for the psycho acoustic processor.
This is basically clear to me if I think about all that sectioning
and windowing.

So a good test would be single beats on a snare drum or even better
snappers or wood sticks or drum sticks , rim shot, everything
short and pulse like.

Newer code development is attacking theses problems specifically.


m.c.

:::Date: Mon, 08 Jan 2001 20:31:29 -0800
:::From: patchell <patchell at silcom.com>
:::To: Colin Fraser <colinf at ntlworld.com>, "synth-diy at node12b53.a2000.nl" 
<synth-diy at node12b53.a2000.nl>
:::Subject: Re: Digital audio listening test
:::Content-Transfer-Encoding: 7bit
:::
:::    I did something like this.  I used Stravinskys Firebird suite from the
:::Telarc recording.  Nobody was able to get them all correct.  I also asked 
that
:::they say which one sounded the best.  Most people picked the MP3 
versions....One
:::of these people had about 10K worth of equipment (Tube amps, electrostatic
:::speakers, real big suckers), even he could not pick the correct ones.
:::
:::    Not too sure what this proved, but it was interesting
:::
:::Colin Fraser wrote:
:::
:::> Here's a little quiz for you guys then...
:::>
:::> I ripped roughly 20 seconds of audio off a professionally produced CD by a
:::> well known German band...
:::> (I'm open to suggestions for a 'real music' candidate for the same 
listening
:::> test)
:::>
:::> I converted it to 256 kbps mp3 and 128 kbps mp3, then decoded these to wav
:::> files.
:::> I also transferred it digitally to minidisc, then back.
:::> For good measure I also encoded the minidisc transfer to 256 kbps mp3.
:::>
:::> All transfers were done in the digital domain.
:::> The final results are in 16 bit stereo, 44.1kHz wav files.
:::> The 5 files are zipped up at http://www.doorsbydesign.demon.co.uk/wavs.zip
:::> It's an 18 Meg file, so modem users beware.
:::>
:::> Anyone care to match the 5 files to the 5 encoding processes ?
:::> The prize is deep respect for having 'golden ears'...
:::>
:::> If you can't hear the difference, then thank god you don;t need to spend a
:::> fortune on hi-fi gear.
:::>
:::> Colin f
:::>
:::> ----- Original Message -----
:::> From: "Goddard, Duncan" <goddard.duncan at mtvne.com>
:::> To: "Synth DIY" <synth-diy at node12b53.a2000.nl>
:::> Sent: Monday, January 08, 2001 7:12 PM
:::> Subject: RE: minidisc
:::>
:::> > >>>BTW Wavelab bit depth calculation proves the MD records all 20 bits
:::> onto disc.<<<
:::> >
:::> >
:::> > ? how does it do that, then?
:::> >
:::> > most of my misgivings re this format are subjective; I didn't bother to
:::> learn all about atrac coding when it first appeared, I read as far as "and
:::> this part is thrown away because this other part is happening at the same
:::> time and it's louder so no-one will notice if that first part's not there
:::> anymore and that, boys and girls, is how we get 16 bits down to 4.....".
:::> > "bollocks," I thought to myself, "but it'll be ok for walkthings". then
:::> when I got one and listened to some familiar stuff, it sounded like it had
:::> been remixed in a subtle but significant way. but as I said before, the 
very
:::> thing that makes it an inferior reproducer (and I'm being picky) make it
:::> useful for live recordings- it seems to filter out the things that your ear
:::> would filter out, which I suppose was their point. it's just that as a
:::> reproducer, it filters out too much.....
:::
:::--
::: -Jim
:::------------------------------------------------
:::* Visit:http://www.silcom.com/~patchell/
:::*-----------------------------------------------
:::*I'm sure glad Merry Christmas comes just once a year
:::* -Yogi Yorgensen
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