The soundstage of an audio recording is a very subtle thing.

Absolutely. Just think about it: in proper soundstage 'images' can be located a close as one foot apart! Our ears (and brain) interpret this from the tiny differences in delays between sounds reaching our left and right ears. Even at the speed of sound (as opposed to the speed of light , these time differences must be extremely small (I don't have a calculator ready: maybe someone with more Physics 101 than I have, could calculate the difference).

If one wants proof if mechanical isolation from a mat as used by Paul does make a difference, it is essential that the play-back chain is capable to maintain these subtle timing differences: it's time accuracy needs to be higher than the differences induced by properly isolating the player (and/or D/A converter; pre-amp; amp; speakers; etc). Therefore, one needs a pretty decent system to detect the effects that Paul's ears have heard. Thus, in order to do a blind test, one also needs to define the playback chain, and set-up.

Also, some equipment (especially higher-end stuff) has been built to minimise mechanical feed-back.Thus ideally one needs a good player that is poorly isolated. The magazine Stereo (Germany - April 2000) did something like this when they published a series modifications to a Sony CDP-XA7 player. I can't remember all the details, but besides improving the power supply they changed the player's feet, placed it on a heavy slate of stone, and added a load of bitumen padding to the inside of the box. This caused it to play like devices many times its costs.

Of course, all of this is pretty meaningless to the empeg discussion: empeg is not a CD-player; MP3 is not WAV; and in-car amps, speakers and wiring, together with the difficult environment (noise, electrical noise, lack of space, odd shape, variety of reflection/absorption) will induce so many other artifacts, that it will hardly be worthwhile to place Emma (or Mark) on Paul's mat .



NB: there is also evidence that compression changes the timing of recordings: immedeately prior to a transient there is a kind of pre-echo that in effect announces the transient's imminent arrival.

HiFi News / Record Review (from the UK) did articles on this in May and June. They used the clacky sound of a castagnet to compare the timing eight codecs in including Dolby Digital,MP2, MP3, TAC and MS-Audio. MP3 (at 128 bps) started to announce the clack some 10 milliseconds early. MP2 at 128 kbp is more accurate (pre-echo at 4 milliseconds), just as Dolby Digital at 128 kbps; MS-Audio started as early as -20 milliseconds; TAC was the earlies at -50.

This may indicate that some of the loss in soundstage is not due to the empeg, but caused by MP3 technology.

Henno
ex 00120
did score one of the 40