Widening/Narrowing stereo image?

[joliom]

Is there an effect or process that would allow me to widen or narrow the stereo image of a particular song? For instance if a song is arranged with the vocals in the center of the mix (at 12 O'Clock), the guitars and drums on the left (at 11 O'Clock) and the orchestra on the right (at 1 O'Clock), but I wanted to widen it to 9:00/12:00/3:00 - is there some way to do that in Audacity?

Oh, and for the record, I'm running version 1.3.8 on Windows XP.

[steve]

s there an effect or process that would allow me to widen or narrow the stereo image of a particular song?

There is a "Stereo Butterfly" plug-in available from here http://audacityteam.org/download/nyquistplugins
In fact there are several listings for it - I've not checked if they are the same or different.
If these do not do what you need let me know, I've got a Nyquist plug-in somewhere that I wrote which may be of use but I'm not sure where I put it.

[kozikowski]

The theory is pretty simple. Convert L and R to L+R and L-R and then back. What you do with the L-R signal in the middle -- plus or minus amplification -- affects separation. If you reduce L-R to zero, the show turns to mono.

There are one or two steps you need to do in the middle to insure against clipping damage, but that's basically it.

Koz

[joliom]

Koz, is that using the plug-in that Steve recommended?

[kozikowski]

It might be. That's the philosophy of FM Radio which actually transmits Mono and Separation to your home, not Left and Right.

There are tools in Audacity to do each of these steps manually. It's pretty painful, but it can be done. I can only assume Steve did it once successfully, wrote it all down, and designed software tools to do it for him.

Koz

[kozikowski]

One of the hidden problems with developing tools is the interface. Without the pretty pictures, sliders, and adjusters, there's no way to tell ahead of time what you're doing. What does 20% greater separation sound like? How do you know you got 20%?

Like driving down the road with your eyes closed and coming back the next day to see where you went. If it wasn't were you want to go, start over and turn the wheel a little different.

Also unsaid in all this is the sound system. You need a killer sound system to hear what happens during audio production. The $19 speakers that came with the computer are probably not going to cut it.

Koz

[steve]

I can only assume Steve did it once successfully, wrote it all down, and designed software tools to do it for him.

That plug-in is not one of mine - it was written by David R. Sky
I guess you're right about how he approached writing it.