Stereo Spreader - anyone ever make one like this?

Hi people,

I'm wondering if anyone has ever made this stereo spreader.  At first I thought it was an "EMI" stereo spreader but I think this circuit was actually from Electronic Musician magazine.

It looks reasonably simple.  I was thinking of making a board with a couple of these for my summing/bussing project that is up and coming.

I figure a switching pot would be best to keep the same amounts of distribution of anti polarity in the opposite channel right?



CC

I made such a similar thing, (back in the 80s) using transistors instead of opamp. I say it could improve the listening experience on some music materials. You can make your stereo speakers sound very wide apart, or collapse them to mono at extreme settings. 

Lout =Rin - Lin
Rout =Lin -Rin

I figure a switching pot would be best to keep the same amounts of distribution of anti polarity in the opposite channel right?

Click to expand...

I would stick with the pot instead of a selector switch. Sometimes little adjustments on the pot can have big effect on sound (again, depending on the source material.)

I was thinking most dual 100k pots that are in my reach have about 10-20% variability.  So one channel could be subtracting 20% more than the other channel.  That could really tilt things.

I was thinking of inserting these on a stereo subgroup prior to an active summing stage (with other sub groups).

I'm really struggling in general to get pots that keep both stereo channels playing nicely together and doing the same thing.

Ideally, I think a switched pot with another pot for fine tuning would be great.  I don't know how to do that yet but I'm going to do some searching. 

Any suggestions?

CC

> struggling in general to get pots that keep both stereo channels playing nicely together and doing the same thing.

If your singer jumps 2 feet to the side when you fade now, with a "spreader" she will jump 4 feet.

Isn't there a MUCH simpler no-track "stereo enhance"?

Well that's sure as heck a lot simpler.  I think I could make a dead bug version of that to test drive.

Thanks.

CC

PRR said:

> struggling in general to get pots that keep both stereo channels playing nicely together and doing the same thing.

If your singer jumps 2 feet to the side when you fade now, with a "spreader" she will jump 4 feet.

Isn't there a MUCH simpler no-track "stereo enhance"?

Click to expand...

Anyone made this?

sheadstedford said:

PRR said:

> struggling in general to get pots that keep both stereo channels playing nicely together and doing the same thing.

If your singer jumps 2 feet to the side when you fade now, with a "spreader" she will jump 4 feet.

Isn't there a MUCH simpler no-track "stereo enhance"?

Click to expand...

Anyone made this?

Click to expand...

Shea,

I've been watching your threads on the whole stereo spreader thing. I'm a mastering engineer and I use MS very often in my work.  In certain situations it is slightly preferable to have it in the analog domain but 9 times out of 10 doing it digitally makes more sense.  So I would say if you want to spread your stereo use a plug in to do it, it's easy and more or less perfect (from a mathematical standpoint at least).

This leads us to the next question - do you really want to spread your stereo?  Turning up the difference information (the stereo stuff) means turning down the sum information (the mono stuff in the centre).  There a quite a few important things in the centre usually, you know vocals, kick, snare, bass......

I can see why a stereo spread gizmo can seem like a more betterizer but it actually rarely works out that way.  Mastering guys use MS in a different way to be able to gain a little more control when eq finished mixes.  I'd say try this out with a plug, if you are still jazzed on the effect in a months time then maybe think about building into a unit. If you do I'd suggest using Wayne's circuit, a lot of thought went into that one.

Good luck.
Ruairi

Thanks mate, i understand you completely, it may do more harm than good. Im just really experimenting with some different mod ideas for my uni dissertation and trying to get as much info/knowledge as possible.
Its either a stereo spread or wet/dry parrallel pot and the arguments for both are pretty close.
Ive been engineering for a while but this is my first diy project and i have zero knowledge of electronics so my udeas are sometimes far fetched.
I appreciate people like you guiding me on this forum im learning so much so quik.
The thought behind the width control came from a uni lecture when a well know british engineer said for years wen he got commisioned a mix, he would put it through a modified piece of gear that sligtly widened the stereo field giving the impresion of a bigger mix.
I understand the principles that to widen the image, the mid is decreased but on slight incriments this can be rewarding but too much is just too much.
P.s. Which one is wayne?

sheadstedford said:

Thanks mate, i understand you completely, it may do more harm than good. Im just really experimenting with some different mod ideas for my uni dissertation and trying to get as much info/knowledge as possible.

P.s. Which one is wayne?

Click to expand...

Wayne Kirkwood.

Best,

Udo.

I've toyed a lot with that kind of concept. Don't expect too much from it.
I would suggest you experiment with this variation of PRR's suggestion. You can make the C switchable.
This one won't affect that much the M level and even better achieve your goal, processing only the frequencies that matter in terms of space positioning.