How To Clean Piano Black Speaker Finish?

You can purchase piano cleaner fluid, and use a microfiber cloth or similar (e.g. piano cleaning cloths).

They're speakers but its really automotive paint so clean the same way you would a car you wanted to concours. Only difference is the car would be a lot bigger, and dirtier. But same technique.

Fold your soft microfiber cloth. Clean in straight lines. Do not go in circles. This way, if you do make a scratch, it will be visible from one angle only. Circles you can see from everywhere. Which I'm sure you have. The halo of swirls that moves around as you go. So don't be That Guy.

You can spray detailer like Griot's Speed Shine on the speaker or on the cloth. Or just dampen with water. Speakers aren't dirty so you'll be fine.

Whatever you do, fold that cloth, and use very little pressure, and clean with a rolling motion that keeps lifting the leading edge of the cloth pulling the dust and dirt up and away from the surface. Make your first pass like this. Then once you have removed all the dust like this if there are finger prints or whatever you can go back and use a little more detailer to get those. When cleaning those you can go back and forth if you are careful but never anything but straight lines until you are sure the surface is clean.

Now if you do get a scratch, well if its not too deep you can remove it. First use Griot's Paint Cleaning Clay. (Which you can do anyway, and will be floored how good your speakers will gleam if you do.) Then use Machine 4 Polish, a very fine polish. Finally, not necessary because indoors but Best of Show Wax will bring out depth you never knew was there.

Overkill, especially in a dark listening room. Then again it is piano black. Do all this and your speakers won't just disappear in the sense of throwing a sound stage. They will disappear because they have such a mirror finish you won't even see the speakers but only the reflection in them.

Miller gave good advice. I just use a premium detailer spray like Meguiars or Mothers and I get a very satisfying shine on my piano black von Schweikerts

+1 Millercarbon.  Griots speed shine is awesome stuff!  I use that on my car, after 3 days of wet sanding, buffing, and waxing of course ;) Primo stuff.

But yeah, treat it like a cars finish.  Pretty much exactly as Millercarbon describes.  Once you have the finish dialed in Speed Shine is all you need.  I would recommend spraying it on your microfiber towel, not directly on the speakers as to not get overspray on the drivers.  I’ll only use damp microfibers on the fronts next to the drivers.  I’ll also use a soft paintbrush to dust the my mid bass drivers (particularly on the surrounds).