I’ve been thinking of ways around it, and one idea I haven’t tested, but kind of conceptually mapped out in my head to try at some point, is to take the synth line, export it, push that through a speaker and record that back in.
At that point, the synth track becomes more “acoustic” in that it’s traveled through the air and come back through, which the hope is would make it easier to mix with something like a guitar.
The downside is that you’d have to go back through and do clean up work on the synth to mitigate any artifacts just like you do for guitar, and you’d need to learn to treat it with a whole panel of compressor, delay, etc… whatever, just like you do with guitars normally.
Basically what I’m saying here is that you export the purely digital out into the real work and suck it back in via mic and in so doing move yourself back to the 1970’s where at least the issue was mostly about the shear volume of the concentrated power rather than the purity lacking any scattering, and it trying to be mixed with things that have more messy profiles from being part of the real world.
There’s clear downsides to this, don’t get me wrong. You’re openly downgrading the quality level of that synth by doing this (however, to be honest…I don’t think the common ear will be able to tell at all that much…provided you have reasonable speakers and mic).
Conversely…now that I think of it…I wonder if there’s a VST out there that adds harmonic resonances and overtones to sounds. Because that would sort of do the same thing without a lot of this hassle.
I mean, pipe it through an overdrive and then clean the overdrive back up on the other end (synth > overdrive > harmonic resonance generator > overdrive cleanup) and you’ve pretty much got a profile that should be well scattered instead of isolated.
To be honest, this is why I use flangers so much.
I don’t even turn them up that high a lot of the time. It’s just that it’s on. Most often barely on.
But just having it pipe through one with rate turned all the way down, or nearly, just allows a bit more breath in the spectrum and L/R space.