What I originally thought to be a simple question with a simple solution
seems to be subtly more complex (or maybe I'm making it more complex than
it needs to be).

I'm working on some files that started their lives long ago as mono analog
recordings (on magnetic media).

Somewhere along the way, they were transferred as stereo (L=R) - so still
a mono recording (48/16) in stereo format.  These are the preservation
(2-channel mono, 48/16).

What to do with the submasters (48/16) and derivatives (44.1/16 and MP3)?

Make them mono?

Retain the stereo format?

My knee-jerk reaction was to go mono for submasters and derivatives.  This
true to the original media, gets rid of an inappropriate redundancy (I
and Left really does equal Right bit for bit), and is also more efficient
storage.  We would not touch the original 2-channel mono files (what is the
right name for these anyway?) that are the preservation masters.

Fly in the mono ointment?  For the technically savvy, no.  For the less

I think in most situations the mono format is perfectly fine.  Most software
can handle the mono WAVE and MP3 without problems.  Quicktime, iTunes and
iPods can even deal with 24-bit and 48 kHz (even 192 kHz).

One exception is if you want to burn CD Audio optical discs from the 44.1/16
mono WAVE submaster.  You'll need to copy the mono channel for stereo, and
then make your Audio CD.  This could stump some people.  Or perhaps not?

Anyone want to weigh in?  Maybe an overlooked compatibility gotcha?  Maybe
mono isn't a big deal for most people?  Maybe CD audio discs for access are
going the way of the dinosaur in today's archives?

Which do you prefer when your preservation master is mono - stereo (L=R)
or mono submasters and derivatives?

Eric Jacobs

The Audio Archive, Inc.
tel: 408.221.2128
fax: 408.549.9867
mailto:[log in to unmask]
Disc and Tape Audio Transfer Services and Preservation Consulting