James Shatto, you wrote re post-processing of MS recordings:
> Yes the sample rate remains the same. Yes the file size probably remains=
the same. And yes the duration of the recording stays the same. But I fi=
nd it hard to believe that a twice edited digital file (L/R -> M/S -> L/R) =
is a bit for bit exact copy of the original(even if you exclude the headers=
from the comparison).
I wouldn't expect it would be, but the "generation loss" would be down in t=
he noise bits and insignificant. MS equalization is quite commonly done in =
mastering suites, where you find the best monitors and ears in the business=
.
> Not that any differences are audible to most people. Or reproduce-able b=
y a lot of cheap audio equipment.
I suggest that the difference would not be audible under -any- condition, a=
nd I'm willing to lend you a double-blind comparator system if you want to =
design and report on a serious experiment. A better question might be "with=
24-bit files, how many generations of LR-MS-LR can you make before a degra=
dation becomes audible?"
> Of course the sample count is the same, you're saving out to a file of th=
e same sample rate, same number of channels, and same duration. Independen=
t of actual content. Why would the count of bits change? But is the CONTE=
NT of the bits an EXACT match to the original after edits? If you need to =
do other edits like noise reduction to S, that little bit of irregularity c=
an severely affect the effectiveness of the noise filter.
>
> I suppose I'm going to have to come up with a script to prove my point. =
Perhaps submit a proposal to myth busters. But then again, what is the poi=
nt, that open source audio tools are flawed? That 32 bit FPU's are inaccur=
ate? Analog rules / Digital sucks?
When I worked as a theatrical sound designer, I would edit and play the mas=
ter tapes for the performances. Others thought I was crazy and always used =
dubs, locking the masters away for security, but the losses from just one g=
eneration of tape copy were so obvious that I felt I owed the audience the =
best experience. In a professional production environment (Shakespeare fest=
ival, regional repertory theater) accidental damage to the masters was extr=
emely rare.
Now with file-based production it's a whole new ball game. I'm not nostalgi=
c for tubes or tape.
-Dan
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