Thanks Bernard! I had to go to bed after writing that post- made my brain hurt
I had been reading about this stuff a while back because I bought a frequency shifter (not to be confused with a pitch shifter), which is somehow related to this whole family of effects. I couldn't really find a description of how it works that I fully understood. Somthing about dome filters and quadrature oscillators. Oh well - it sounds cool!! There are some samples of it on the manufacturer page:
http://www.encoreelectronics.com/cont_fs1.htmlI got it mainly for keys and drum-tracks, but it sounds out-of-this-world with bass! When used subtly, it creates this HUGE panoramic spatial spread of sound (similar to a phaser/flanger), and never seems to get muddy. Produces equally good results with distorted bass too. I'll record something with it when I have more time.
The only drag is that you have to install it in a modular synth cabinet (or some other 5u rack), and you need a +/-15v power supply to run it. I have seen a version of the frequency shifter effect made by Analogue Systems that is self-contained in a small wooden enclosure. These show up on Ebay from time-to-time.