I’ve gone through power/grounding noise issues in several of my locations over the years. For me, step 1 is to re-read and follow the advice from this PDF. It’s lengthy, it’s a little bit technical but not full on crazy technical. And I know it’s well within your ability to understand everything in it.
These are the best practices re: connecting things one power supply, balanced/unbalanced connections etc. 9 times out of ten once I’ve realigned my system based on this information my noise floor is effectively gone. If that doesn’t solve it, then I would suspect the possibility of a bad component in the speaker itself. Like a cap or something.
If your location has experienced blackouts/brownouts or has weather events that effect power, I would absolutely get something with a very serious fuse. I once thought regular old power strip fuses would work. Then a transformer station down the road blew and I lost a very expensive computer. I was lucky that the computer took the hit for everything else in the studio.
The power strip I use now (everything of value in my life goes through one of these) is the Furman PST 8 8.
1/20/2024
Ode to the SMRF
The ol’ 4ms Spectral Multiband Resonant Filter (which they foolishly acronym-ed to SMR instead of SMRF) has been a go-to for me for years. 6 bands that can be assigned scales, shifted up/down via CV, frequency nudge/pitch bend via CV etc, splits into 2 ch of 3 bands if you like, each ch amplitude cv controllable (with a switch for making square gates/triggers respond like a vactrol if you like).
It’s big and, the panel is ugly, it does a bunch of things and wrapping one’s head around the scale patterns/selections takes a bit of research. But it is fantastic for pulling tones from field recordings or other material etc. With 2 of em and a spring reverb you could make yourself a cv controllable Fjaerlet.