Triaging FM8 patches for relative n00bs.

Lately my largest synth infatuation has been with programming FM8. So, I've done a little bit of FM with my Virus and understand the theory ... but flipping through the presets in FM8 provides a good sampling of the different timbres possible. So, how does one get a good grasp on what makes up these different FM tones? First of all, you get a very flexible routing matrix of operators and parameters, with the potential to paint very full/dense spectral pictures, and in the process a lot of the fine tuning tweaks can become virtually irrelevant.

Here's an example (click to enlarge):



So, to cut through a lot of what doesn't necessarily or at all compose the sonic character of this patch, let's look at the smallest mod routings.

From Z -> C and D there's not much going on. In fact, whatever those mods might do is inaudibly lost in the much larger spectral content of patch. This is partially because Z's cutoff in this case happens to be pretty low, and so whatever comes through gets lost in the already low-to-midrange output of the patch at large.

Now look at the outputs. There are 4 set to 80. This is going to provide so much output that unless A and Z's output occupy a different part of the spectrum, they're not going to be adding much .... As it happens, though, A is set to the 1+3+5 square, which does indeed provide some higher harmonics that will stand out a bit, but with it's ratio set to 0.7 that is still fairly trivial.

That's it for now. So anyway, there's a bit of structured thinking about how to look at FM8 presets. Learning to quickly filter out the less consequential parts of a patch can help you more easily see what makes up the core tone-making elements of a patch. 8-)