Dave Smith Instruments SYNTHESIZERS

So I saw this tip somewhere else to help with the loss of bass that
occurs at high resonance settings:

Set the same sound in both channels (detuned saws, for instance). With
the filters at the 24dB setting, increasing resonance cuts the
passband as on the Moog filters. Set Envelope 3 to minimum attack,
maximum decay and release, and sustain to maximum. This "creates" an
offset, a continuous "on" signal while the keys are gated. Modulate
one filters' resonance up (just one), or of the overall resonance
level is high, us it to modulate one filters' resonance to its
minimum. You get the resonant character plus the size of the
non-resonant filter. Use Tri and Sine waves on that side too.

In order to do this would you have to use "Filter Split"?  Or is there
another way to modulate only one of the filters?