You should take a look at how the keys are split in this patch:
Keyboard’s lower octave controls the samples. The upper octave controls the synth. You can control the mix between the two keyboard octaves if you put the crossfader between the output of the simple objects (the synth voices) and the catch~ samp_voice_out (the sampler voices)
On second thought, you don’t need to look at that other patch.
- Create a copy of the sampler-voice.pd (e.g. sampler-voice2.pd). Use the first one for lower octave (keys 0-11), the second for the upper octave (keys 12-23).
- Change the throw~ samp_voice_out object in the sampler-voice2.pd to throw~ samp_voice_out2.
- In main.pd, add a catch~ samp_voice_out2 object and add a crossfade between catch~ samp_voice_out and catch~ samp_voice_out2
- In main.pd change the upper 12 of the sampler-voice objects to sampler-voice2