Added another thingamabob for adding stereo to things that lack it. It converts the signal to mono, then uses two all-passes to get some comb filtering going. The comb filtered outputs are added in opposite polarity to each channel, such that when you go back to mono, the original signal is recovered without phase cancellation artifacts.
It sounds good when applied gently. Applying too much will result in something that sounds a bit like it's been flanged on stereo headphones, so be aware of this. The crossover is basically a HPF that cuts the bass of the widening to avoid widening the bass too much.
The last slider allows you to mix in the original side channel (which can optionally also be run through the 12-pole highpass).
Fixes:
Gain issue in Squashman should be fixed now.
HP issue in MS-20 should be fixed now.