From: smee@bristol.ac.uk (Paul Smee)
Newsgroups: rec.audio
Subject: Re: Terms
Date: 8 Apr 92 09:23:54 GMT
Reply-To: P.Smee@bristol.ac.uk (Paul Smee)
Organization: University of Bristol

In article <702613415.11504.0@unix1.andrew.cmu.edu> ri09+@andrew.cmu.edu (Robert W. Igo) writes:
>The only person who responded mentioned that you should be able to
>tell where the instruments are in relation to you (the listener).
>Well, isn't this highly dependent on the source recording?  I didn't
>think that speakers could create something out of nothing like that.
>Could someone suggest a CD or tape to buy which would enable us to test
>to see if our systems have good imaging?  Maybe a walk-through?

Right, occurred to me last night that I could have expanded a bit more
on both imaging and transparency.  These are characteristics of a stereo
system, but they are also characteristics of recordings.  It is possible
for the recording studio engineers to mix a recording in such a way that
no matter how good your system is, you won't get any imaging and you won't
get any transparency.

It's further complicated by the fact that your listening room enters
the equation.  Any particular set of boxes will have a sort of
'potential imaging and transparency', but when you put it into YOUR
particular room, you can make things worse (a lot) or better (a bit)
than their notional potentials by adjusting exactly how you position
your speakers in the room, and by experimenting with rearranging the
other furniture in the room.  (To what extent you want to bother with
this is a matter of personal taste.  But you can certainly set up an
amazing system in such a way that it will sound horrible.)

For checking these, recordings on the Chesky label are good; they are
well engineered and normally have the potential for good imaging and
transparency if your system can do it.  The Chesky Jazz Sampler, which
someone else mentioned, also contains a set of 'demonstration' tracks
which are supposed to show imaging, and the liner notes explain what
you're supposed to hear.  If you want to try blind, listen first, then
read the notes, but if you do that, at least check and make sure you
stop the CD before it gets into the test tones at the end -- don't just
wander off and leave it spinning.

If you prefer classical, Telarc recordings usually show pretty good
imaging and transparency -- though I don't always like the
interpretations of the conductors that they pick.  (There are lots of
other good recordings, but these two brands feel consistent for
experimenting.)

Kraftwerk (the 'Radioactivity' and 'Autobahn' albums) and Pink Floyd
(Dark Side of the Moon -- you can't go to a hifi show without hearing
that being used to demo about 10 million different brands of speakers)
can also be fun for spotting imaging, though in their cases it's
generally 'artificial' imaging -- the recordings have been engineered
to make 'effects' move around the sound field.  Finally, modern C&W and
bluegrass recordings are usually pretty good for starting out with.
The groups tend to have not too many (4 or 5) instruments, and that
sort of music is usually miked and mixed pretty straightforwardly so
that each instrument has a place to be, and stays there.  Dire Straits
is usually pretty good, and the sort of countryish CD by Mark Knopfler
and Chet Atkins is good (you can tell who's talking over whose shoulder
on each of the cuts).

Or, for imaging particularly, just pay attention to some of the
recordings you own.  At least one of them must have good imaging, and
once you've spotted it you'll recognize it, and then be able to tell
whether it's there or not for all the others.

-- 
Paul Smee, Computing Service, University of Bristol, Bristol BS8 1UD, UK
 P.Smee@bristol.ac.uk - ..!uunet!uknet!bsmail!p.smee - Tel +44 272 303132