Stereo Expanders

[SirRus]

Just curious as to what this VST does in general. When I use it on my Cubase mixes everything sounds much more spread out, as it the name would imply, but why is that? What is it doing exactly, I mean if my audio is panned to a certain distance L/R what exactly is the stereo expander doing to make this overall sound crisper and more spacious in the audio field? Are these generally recommended to add onto the final mix, and if so how much (on a scale of 0-100 with my Steinberg plug-in)?

Thanks for any advice in advance!

-Ravi

[zircon]

Stereo expanders can work in different ways. A lot of them simply delay the signal on one side, pan the delay 100% in one direction, and then pan the original signal 100% in the other direction. Though the delay is miniscule (usually no more than 10ms, and even that is excessive), your brain easily perceives and processes it and thus it sounds far wider. If you simply took the same track, duplicated it, and then panned the two in opposite directions, you would not hear any differece. Your brain needs some sort of time information to help process stereo image. The problem with this method is that if your mix is compressed to mono, you will get LOTS of phase cancellation and it will sound awful. This is the main method I am familiar with.

Other expanders use different, more advanced mechanics that involve changing frequencies and phases to achieve the same expansion effect without sacrificing mono-compatibility. I don't know how, though.

[lazygecko]

Are you sure you don't mean stereo separators? Stereo expanders should just increase the "distance" between the left and right tracks.

[MaliceX]

In Sound Forge, stereo expansion works by adjusting how much of the overall signal is going from original to total inversion (ie: both channels mixed but inverse to each other)

The definition about miniscule delay zircon mentioned has a preset in Sound Forge called (Pseudo-Stereo).