Experiments on Stereo Widening

There have been threads before. Nevertheless I thought something to play with might be useful. I have been trying and experimenting for a while and recently watched this instructive video... And I experimented again. I was especially looking for ways to widen the stereo field for both tonal and percussive sounds.

One thing you can do with these is to add a short delay to one channel. It has to be long enough to avoid a virtual direction of the sound by the Haas effect, but not too long so as to avoid the impression of an echo.

Another thing is to use the m/s version of a sound and play with the side signal. I read this is a quite common technique.

Well, here is something to start with. The Logic file contains two tracks one of which is a mono track that is made stereo by a combination of a Sample Delay and and the Direction Mixer. In the output strip there is a multimeter to watch the visualised stereo field and a Gain plugin to easily make the output mono (by the Mono button) to check the mono compatibility.

The basic idea is to use the mono source signal for the "m" channel - and then add stereo information for the "s" channel that is derived from the mono source by delaying it.

The advantage of just playing with the "s" channel is that whatever is added to one side will be subtracted from the other side so the sum of the left/right modification is always zero - no change in the sound when you switch to mono.

Of course there are still some important considerations. Whatever you do to get your side signal, it should not spread over time too much, otherwise you will get echoes or reverb that completely vanishes in mono. You also have to watch levels - too much stereo content can make the sound appear much louder.

In this file the mono signal is sent to Bus 30 and from there to Bus 40 (Aux 22) and Bus 41 (Aux 23). Aux 22 is fed into the "Mid" input of the Direction Mixer in Aux 24. Aux 23 is used to get the "Side" information. There are two active plugins in there: Mainly the Sample Delay and additionally a high cut filter. The latter can be used to avoid the impression of doubled clicks on very percussive sounds. If you like, you can disable the Sample Delay and enable the Chorus instead. Of course you can try different settings and other plugins to get stereo effects. Don't forget you need a mono effect here as only one channel is fed to the direction mixer as the "s" component. Switch to mono every now and then to compare. Have fun (I think it is)!

Stereo.logic.zip

Thanks for this.

You're welcome There are so many fancy tools out there that really can help you, but I think it's always interesting and educational to build something with very simple components.

Well it certainly helped me. I'm not very familiar with the concept of m/s or even exactly how the direction mixer works, so it was good to be able to look it up in the manual and get acquainted with it, and then use your project to work out m/s reconstruction / stereo widening. It's amazing how a simple frequency filter can affect the stereo image so much.