I agree with Richard 100% and I can't see any sense in keeping a dual-mono file out of phase to each
other. That's crazy. If someone must, for some dumb reason, hear "the actual original tape audio",
then flip the polarity on one channel and burn them a CD and let them hear the wonderful sounds of
FYI regarding polarity and phase ... I have found numerous times on mass-duped reels from the 50s
and 60s that a channel went into the duper with one polarity and was recorded on the slave with the
reverse, putting the channels out of phase to each other. This can be caused by sloppy wiring on a
slave's replacement head. I also think Ampex made errors at the factory sometimes on the dupers,
having a polarity reverse somewhere between input to the master playback electronics and output to a
given slave's record head. There could also be sloppy phase-QC in making dupe masters (which were
generally not made by the recording engineer or the best engineers at a given facility). I was
surprised to find this problem on a couple of Concertapes 2-tracks from 1955 and a Mercury 2-track
from 1957. Have not found the problem so far on the handful of RCA 2-tracks I have. Found numerous
times on various tapes I transferred for a private collector, most of which were sold through a
music-tape club similar to the Columbia Record Club, in the 60s. Most of those tapes were duped by
Ampex in Illinois. Also have had phase-reverse problems on Mercury quarter-tracks made by Bel Canto
in Indiana (the world's worst duper, ever). My point is, untrained ears don't seem to hear phase or
polarity as critically as audio engineers should, or people just accepted crappy sound quality on
pricey reel tapes in the 60s (this I doubt).
-- Tom Fine
----- Original Message -----
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, February 07, 2013 10:18 AM
Subject: Re: [ARSCLIST] Mono but Out-of-Phase
> Hi, Henry,
> If you wish to save the preservation master precisely as found, that would be acceptable and
> probably the correct thing to do, but include a note in the metadata about what you found.
> I would STRONGLY urge you not to release to the public anything dual mono. It just wastes
> bandwidth. If you feel that you must release dual mono to the public I would EVEN MORE STRONGLY
> urge you to NOT release the out-of-polarity files as is, but rather flip one channel. Attempt to
> learn the Wood Effect and see if you can determine which channel is correct. If this is mostly
> speech, you should notice that the positive peaks are, well, peakier than the negative peaks. Same
> area under the curve, but a different shape--slightly.
> On 2013-02-07 9:16 AM, Henry Borchers wrote:
>> "NEVER SUM TWO MONO TRACKS TOGETHER EVEN IF IN PHASE AND IN
>> ALIGNMENT. NEVER. ALWAYS KEEP THEM SEPARATE -- AND IT IS BETTER TO
>> ONLY COPY ONE OF THEM IN THE FIRST PLACE."
>> I should clarify, I don't plan on summing them into a file. However, I'm
>> am a little worried about users having phase cancelation issues if someone
>> were to play the file on a mono speaker (like on a phone or a tablet. Does
>> anybody know if the speaker on the iPad is mono or not?) where they manage
>> to sum left and right.
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada 647 479 2800
> Quality tape transfers -- even from hard-to-play tapes.