[Wavelength]

The noise from the servopack is due to SERVO ON, this will always cause some noise.

Seems they could have just stopped here. It makes absolutely no difference if you are trying to move the motor, no difference if you are introducing any perturbations at all; the noise is simply there when the servo is on.

My motor wiring is only about 75cm long, and the reactor Yaskawa calls out doesn't seem to be easily found online anyhow, so not sure it worth messing with that for me.

Looks like I will be moving forward with the cold-plate acoustic box.

Bad news, but thanks everyone for the help. At least I can move forward with more confidence.