[78-L] Removing hiss - yet another idea

[Michael Biel]

It ha been done.  During WW II when monitoring international broadcasts, 
occasionally they would listen with stereo headphones to two 
simultaneous transmissions of the same program on two different 
frequencies.  If the signal path is the same, the audio can fuse in the 
center and leave the differing noise and interferences off to the sides.

  The same can be said for stereo playback of a mono record. The sound 
fuses in the center and the surface noise separates off to the sides.  
And Walter Welch synchronized two diamond disc players with a single 
electric motor inbetween the two machines.  He did it as an experiment 
in effectively doubling the length of the horn to lower the lowest 
effective frequency.  I didn't hear any difference. But it proved that 
two turntables could be synchronized.

Mike Biel  mbiel at mbiel.com

neechevoneeznayou at gmail.com wrote:
> Interesting concept, but surely syncing the 2 sides up would present a 
> problem, as we have discussed here many times whenever the subject of 
> accidental stereo comes up. OTOH, maybe using a digitally controlled 
> table would provide speed uniform enough to do this? Proper centering to 
>   an *extremely* narrow tolerance would be a prereq, I would think, as 
> the tiniest amount of wow would cause a pitch shift, maybe too small to 
> hear but large enough to confuse your computer doing the comparison.
>
> joe salerno
>
>
> John Wright wrote:
>   
>> When I'm restoring I start with a stereo file and sometimes see noise in 
>> one channel and not in the other, which is useful, cut'n'paste the good 
>> bit.
>>
>> Now,
>>
>> David Burnham wrote
>>
>> "the main problem with all noise reduction systems: how do you 
>> distinguish between signal and noise? "
>>
>>
>> That got me thinking. If you have two 78s of the same recording the 
>> music is the same, but the noise is different, and likely different all 
>> the way through.
>>
>> So has someone invented a computer program that compares the two 
>> recordings and just saves the sound that is COMMON to both? i.e. the 
>> music?
>>
>> Let me have a share in the new patent, please :o))
>>
>>
>>