[78-L] Multiple disc playback, was Removing hiss - yet another idea

[Doug Pomeroy]

The signal which is common to both groove walls is what you get
when you make a (well-tuned) mono mix!  If it 's any more
complicated that that, you will have to educate me.

As for perfectly synchronizing the playback of several copies of the
same recording, the absolute possible improvement in the signal-to-noise
ratio is 3 dB with 2 discs, 6 dB with 4, and 9 dB with 8.

Yes, perfect synchronization is essential and this is VERY difficult.

At an ARSC conference in Nashville a few years ago I gave a talk
about this subject and somewhat jokingly showed a picture of a "stacked"
turntable, powered by a single motor, which could play several copies  
of the
same recording all at the same time, the idea being that individual  
disc start
times could be fine-tuned digitally after the transfers were made.   
This WOULD
work.  But, A major problem would be finding eight decent copies of a  
very rare
recording, such as King Oliver's Snake Rag ;-)

doug pomeroy

> Message: 15
> Date: Mon, 8 Feb 2010 11:44:13 +0000
> From: John Wright <vintage at jabw.demon.co.uk>
> Subject: [78-L] Removing hiss - yet another idea
> To: 78-L at 78online.com
> Message-ID: <FiJ3ghDNk$bLFw8B at btinternet.com>
> Content-Type: text/plain;charset=us-ascii;format=flowed
>
> 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))
>
>
> -- 
> John Wright