One thing I've found that works well is multing the envelope that opens the vca for the kick, sending it to, say, Maths ch. 2, attenuverting it ( 9 oclock dial position), taking the INV out to the vca for the basslines, to get a nice "ducking" effect.

Yes, I've done it with a basic Intelligel Quadratt as well. Works very well. Though it's worth experimenting with the envelope and whether the VCA is linear/exponential to see what the effect is. I use a compressor in my iPad for sidechaining which also gives plenty of possibilities. I like the witch house exaggerated ducking, which is hard to achieve by using the original kick envelope.

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