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OT: Converting from Mono to Stereo

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  OT: Converting from Mono to Stereo JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-04-25 16:46 -0400
    Re: OT: Converting from Mono to Stereo nospam <nospam@nospam.invalid> - 2015-04-25 17:05 -0400
      Re: OT: Converting from Mono to Stereo isw <isw@witzend.com> - 2015-04-25 21:10 -0700
        Re: OT: Converting from Mono to Stereo JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-04-26 02:01 -0400
    Re: OT: Converting from Mono to Stereo Paul Magnussen <magiconinc@earthlink.net> - 2015-04-25 14:11 -0700
      Re: OT: Converting from Mono to Stereo Warren Oates <warren.oates@gmail.com> - 2015-04-25 17:23 -0400
        Re: OT: Converting from Mono to Stereo JF Mezei <jfmezei.spamnot@vaxination.ca> - 2015-04-25 17:54 -0400
          Re: OT: Converting from Mono to Stereo nospam <nospam@nospam.invalid> - 2015-04-25 17:57 -0400
          Re: OT: Converting from Mono to Stereo Warren Oates <warren.oates@gmail.com> - 2015-04-25 18:03 -0400
        Re: OT: Converting from Mono to Stereo billy@MIX.COM - 2015-04-27 16:08 +0000

#74047 — OT: Converting from Mono to Stereo

Hoping someone here would know what tricks to use.

I have old movie that is mono.  Would like to convert soudntrack to
stereo or even 5 channels.

I know how do create the different tracks etc.

What I do not know is what sort of processing/filters to apply to each
track to give a multi-channel experience instead of having all tracks
carrying  identical sounds.

Any hints ?

I did this with a song from the Sydney olympics which was recorded mono
and added very light time delay on one track to give a stereo effect,
but that worked because it had a "stadium" feel to the song to begin with.

Just wondering what other tricks exist to professionally give a stereo
or multi track effects from a single track ?

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#74051

In article <553bfd31$0$64062$b1db1813$2411a48f@news.astraweb.com>, JF
Mezei <jfmezei.spamnot@vaxination.ca> wrote:

> Hoping someone here would know what tricks to use.
> 
> I have old movie that is mono.  Would like to convert soudntrack to
> stereo or even 5 channels.
> 
> I know how do create the different tracks etc.

you can't create what's not there. 

if all you have is one channel, then converting to stereo will have two
identical channels.

about the only thing you could do is manually follow each actor and pan
their audio to match where they are on screen, but that's a shitload of
work, especially where several people are talking and the camera angles
change.

you'll also need to do that for sound effects, such as a car driving
across the frame.

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#74088

In article <250420151705204364%nospam@nospam.invalid>,
 nospam <nospam@nospam.invalid> wrote:

> In article <553bfd31$0$64062$b1db1813$2411a48f@news.astraweb.com>, JF
> Mezei <jfmezei.spamnot@vaxination.ca> wrote:
> 
> > Hoping someone here would know what tricks to use.
> > 
> > I have old movie that is mono.  Would like to convert soudntrack to
> > stereo or even 5 channels.
> > 
> > I know how do create the different tracks etc.
> 
> you can't create what's not there. 
> 
> if all you have is one channel, then converting to stereo will have two
> identical channels.

If you introduce a pair of "all-pass" filters into the two channels, 
where the filters produce a constant non-zero phase *difference* between 
the channels (i.e. the difference in phase is constant regardless of 
frequency), the source will "spread out" between the two loudspeakers. 
As the phase difference increases, the spreading effect does too; at a 
90 degree difference, the sound has no apparent source and will fill the 
space between the speakers.

Isaac

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#74093

On 15-04-26 00:10, isw wrote:

> If you introduce a pair of "all-pass" filters into the two channels, 
> where the filters produce a constant non-zero phase *difference* between 
> the channels (i.e. the difference in phase is constant regardless of 
> frequency), the source will "spread out" between the two loudspeakers. 

Thans. will have to look for such a filter and try it out.

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#74054

JF Mezei wrote:
> Hoping someone here would know what tricks to use.
> 
> I have old movie that is mono.  Would like to convert soudntrack to
> stereo or even 5 channels.
> 
> I know how do create the different tracks etc.
> 
> What I do not know is what sort of processing/filters to apply to each
> track to give a multi-channel experience instead of having all tracks
> carrying  identical sounds.
> 
> Any hints ?
> 
> I did this with a song from the Sydney olympics which was recorded mono
> and added very light time delay on one track to give a stereo effect,
> but that worked because it had a "stadium" feel to the song to begin with.
> 
> Just wondering what other tricks exist to professionally give a stereo
> or multi track effects from a single track ?

Disclaimer: this isn't an expert opinion (although I could probably get 
one for you if you want to go ahead), just that of someone who remembers 
the days of "electronically rechannelled to stimulate stereo".

As I'm sure you know, you can't produce true stereo from a mono signal. 
  There were two basic techniques: adding delay or reverb in the manner 
you mention, to obviate the impression of listening through a hole in 
the wall; and partitioning the signal across the stereo image.

One way of doing the latter, for example, was using high-and low-pass 
filters on an orchestral piece, so that the violins seem to come from 
one channel and the basses from the other.  (If used indiscriminately 
this technique could backfire: as, for instance on the rechannelled 
version of the Patience and Prudence hit "Gonna get Along Without You 
Now", wherein the pianist plays a run from high to low and the piano 
seems to go whizzing across the room.)

The best results I've heard with this technique were on Sinatra's '50s 
recordings.

But presumably, if you're editing dialogue, you could place the 
participants on different sides of the screen?  It would be a lot of 
work though.

Hope this helps.

Paul Magnussen

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#74058

In article <C72dnbJszpNun6HInZ2dnUU7-X2dnZ2d@earthlink.com>,
 Paul Magnussen <magiconinc@earthlink.net> wrote:

> But presumably, if you're editing dialogue, you could place the 
> participants on different sides of the screen?  It would be a lot of 
> work though.

Dialogue should be in the center anyway, although I know they play with 
offstage dialogue left/right these days. JF: What's your source? Is it 
in fact one single mixed mono track? And is it really worth the effort?
-- 
Where's the Vangelis music?
Pris' tongue is sticking out in in the wide shot after Batty has kissed her.
They have put back more tits into the Zhora dressing  room scene.
  -- notes for Blade Runner

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#74063

On 15-04-25 17:23, Warren Oates wrote:

> Dialogue should be in the center anyway, although I know they play with 
> offstage dialogue left/right these days. JF: What's your source? Is it 
> in fact one single mixed mono track? And is it really worth the effort?


sounce is single channel, and IMDB confirms that the movie was
originally done in mono. I know that early James Bond movies were also
done mono and later remastered to stereo, but it isn't clear is the
remastering had the original sound masters available where the music
would likley have been stereo so it would be easy to edit the stereo
version o fthe music into the new sound track for instance.

Is it really worth the effort ?

If there are some simple filters that can give good results, then yeah,
worth the effort. But if I have to do this separately for each scene of
the movie to try to get the right sound, then unless I get paid for it,
no :-)


On a modern stereo, a "mono" soundtrack comes out only from the centre
speaker with the rest unused. Generating differences between left/right
tracks would result in not more speakers involved, so much greater
spacial spread of the audio.

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#74064

In article <553c0d02$0$59480$b1db1813$46decd27@news.astraweb.com>, JF
Mezei <jfmezei.spamnot@vaxination.ca> wrote:

> Is it really worth the effort ?

no

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#74067

In article <553c0d02$0$59480$b1db1813$46decd27@news.astraweb.com>,
 JF Mezei <jfmezei.spamnot@vaxination.ca> wrote:

> If there are some simple filters that can give good results, then yeah,
> worth the effort. But if I have to do this separately for each scene of
> the movie to try to get the right sound, then unless I get paid for it,
> no :-)

Why do you want to do it, then?. I ask because some people collect the 
old mono versions of work by The Rolling Stones and The Beatles (and 
Phil Spector).
-- 
Where's the Vangelis music?
Pris' tongue is sticking out in in the wide shot after Batty has kissed her.
They have put back more tits into the Zhora dressing  room scene.
  -- notes for Blade Runner

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#74339

Warren Oates <warren.oates@gmail.com> writes:

> Dialogue should be in the center anyway, although I know they play with 
> offstage dialogue left/right these days. JF: What's your source?

The _only_ way to make it stereo is to get all the original elements
and re-mix it.  If it's something like the Terminator, you can just
wait for that to get done.

Billy Y..
-- 
        sub     #'9+1   ,r0             ; convert ascii byte
	add     #9.+1   ,r0             ; to an integer
	bcc     20$                     ; not a number

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