Eh. Guys you're making this too complicated - Tres is right, envelopes are the answer.
The reason for the popping sound is simply a loud waveform being cut off short, which pretty much always causes a pop, and trying to adjust the endpoint to make it hit a zero-crossing is tedious as heck.
The solution is to not cut the sound instantly, but instead fade it out a bit. The fadeout can be very very short, it'll still work. To do this, simply enable the envelope, set sustain to full, then adjust the release to something suitable like 0.1 or 0.05, this causes the cutoff to be almost instant but it's still slow enough that it'll smooth out the popping.
The reason for the popping sound is simply a loud waveform being cut off short, which pretty much always causes a pop, and trying to adjust the endpoint to make it hit a zero-crossing is tedious as heck.
The solution is to not cut the sound instantly, but instead fade it out a bit. The fadeout can be very very short, it'll still work. To do this, simply enable the envelope, set sustain to full, then adjust the release to something suitable like 0.1 or 0.05, this causes the cutoff to be almost instant but it's still slow enough that it'll smooth out the popping.