Re: arsclist Transfer of multiple copies, was: Full 3-D mapping of groove?

[Don Cox <doncox@xxxxxxxxxxxxxx>]

On 12/12/02, Doug Pomeroy wrote:

>> Yes, but the Azimuth corrector is not changing pitch.
> 
> I beg to differ. It does change the pitch, but at the level of a few
> milliseconds, which the ear cannot hear as a pitch shift. But that's
> what it is.  As I said, what's needed is a processor which will do
> this with much larger timing differences.

Surely Azimuth correction changes the relative phase of the various frequencies, not the
pitch?

The playback from different parts of the head will have a time
difference, which gives a comb filter effect. The amplitude of various
frequencies is affected, but not their pitch.


>> I suspect it would be better to do the correlation first - noise
>> reduction will remove low level sounds which might otherwise be
>> detected.
> 
> I am very familiar with what CEDAR removes. How much the "low level
> sounds" would be required for the operation of the syncronizer is an
> open question, 

My point was that you would want to preserve them for listening. Also, I
was thinking of the random noise reduction, not the click removal.

However, part of the idea is to use another copy (or copies) of the
recording for waveform reconstruction rather than a calculated curve. If
you do declicking first, the various copies will all be full of bits of
CEDAR-made waveforms.


>> If it's a mono recording, you have two copies on each disc.
> 
> Well, sure.  But the theory refers to the L+R output of one mono disc
> being added to the L+R of another.  (Making sure the L+R is optimized
> in each transfer is of course important, as always.)

The correlation idea would give better results than simply mixing L+R,
so it would be best to treat the L and R as separate sources of
information.

Regards
-- 
Don Cox
doncox@xxxxxxxxxxxxxx


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