We can solve the problem by reversing our approach. Finetooth is a Combinator effect patch that creates a radical difference in the frequency domain using comb filters at opposite poles, basically sculpting each channel with equal and opposite EQ. This creates the greatest possible difference between the two channels for a given signal without compromising phase relationships. (Technically, EQs and filters are actually still made of very short delays, so the phase is changed by definition; forgive me!) Because the channel outputs don’t share any overlapping frequencies, they will sum to a very solid mono mix.
Here's a short demo:
4 bars of a mono Subtractor pad sound, then Finetooth is engaged. After 4 bars, an LFO is passed to Rotary 3, modulating the comb frequency for added stereo movement.
Input Trim
Attenuates the input signal.
Wet X-Over
Sets the crossover frequency where the filtering starts to take effect. This can be used to spread higher frequencies across the stereo field while keeping the low end centered. At the minimum setting the crossover is bypassed entirely, sending the whole signal through the comb filter stage.
Comb Freq
Sets the frequency for the left and right channel comb filters. This can be adjusted if the effect causes an unwanted difference in overall amplitude between left and right channel levels.
TIP: For extra stereo movement, try automating or modulating this rotary with an LFO to create a Leslie-style rotation effect!
Width
Sets the master width of the effect device, post comb filter stage. At the minimum setting, the stereo image is collapsed to mono. At maximum, the stereo image is exaggerated. Note that settings above 12 o’clock will start to introduce phase incoherence and possible cancellation if later summed to mono.
Flip In L-R
Flips the stereo image at the input of the device.
Mono Input
Uses only the left channel’s input signal for the device. Combine with the Flip In L-R button to use the right channel’s input signal instead. This button is engaged by default so that any existing stereo information in the original signal does not cause undesirable phase incoherence.
Comb +/-
Reverses the polarity of the comb filters.
Bypass Filters
Disengages the comb filters.
Download here: Enjoy!