[geeks] Stupid recording engineers

[Joshua D Boyd]

On Wed, Jul 24, 2002 at 01:16:58PM -0400, Greg A. Woods wrote:

> > But to get back to the point, from a quick batch of testing other CDs
> > (before I broke the headphones that is), none of the others noticebly
> > drop instruments when played in mono, so I stand by my suspicion that
> > this recording engineer didn't do his job.  The Mandolin sounds like
> > it is almost perfectly out of phase between the two chanels.  I
> > haven't copied the sound to a .wav file for exact analysis yet though.
> 
> Your "tests" are bogus.  Your results are meaningless.  You're futzing
> with the output of your player when you cross-connect its channels.
> Don't do that.

I understand that it is bad. But the difference between that design,
and the official Rane design for summing to mono is 3 resistors, are
one output.  So instead of
Vr -------------
         |
         |
Vl -------------

V- -------------
We have:

V- --------------
              \
              /
              \
Vr -/\/\---------
            |
Vl -/\/\----|

Where the resistors on Vr and Vl are relatively small (475ohm) and the
resistor bridgeing Vr and V- is fairly high (10k ohm).

Now, to the rane suming circuit, add a y cable to split it again, and
the two circuits are pretty similar.  The voltages and loads are off,
but there isn't anything there to case a phase shift unless leaving
out the 10k ohm bridge would do that, which I doubt.  So, if the
official design doesn't do anymore phase shifting than the bad,
stupid, potentially damaging headphone design, then when two signals
are summed and an instrument disappears, that means that it is so
close to perfectly out of phase between the chanels that I can't heard
whats left.  Now, you could argue that saying this is unusual among
other recordings buy a more or less random sampling, taken from a
non-random subset of all the records out there on CD is bogus, but it
should suffice for the purpose of backing up that this one engineer
didn't do his job to the industry standard.  Maybe he took the view
that you and a few others seem to take in saying screw people who have
a reason to listen in mono.

And if it makes you feel better, I'll copy the song to HD and sum them
digitally, as soon as I can figure out how to do so with the software
installed. 

-- 
Joshua D. Boyd