How To Clean Piano Black Speaker Finish?

I recommend Gerlitz Smudge Off which was personally endorsed for polishing high gloss finishes by an ultra high end dealer. A quick spray onto a MF or other soft scratch free polishing cloth and a gentle wipe cleans exceptionally well while leaving no residue or streaks. It's commonly used on high gloss guitars, and also works well on any gear that's metal, glass, chrome, etc. https://smile.amazon.com/Gerlitz-SMUDGEOFF-Smudge-Spray-Cleaner/dp/B000WIFUDW

Not sure if you saw my pics but Novus is what I finalized my KEF’s with.  I actually have a bottle of Novus on top of one of the speakers in one of the pictures :-)

Gerlitz looks like good stuff as well 👍

b_limo, you are absolutely correct taken in context so I owe Millercarbon an apology. No I have never won a concours, just a Make a Wish contest.
I am sure the mini was a PIA. Who the f--- would do that to a Mini. The Cooper S is a really fun car. I think it may be the best handling FWD out there. It certainly is the best I have ever driven. Porsches are great if you work on them yourself. If not they can be a money pit. I have plenty of scraped knuckles to show for it. Audi just announced they are finally going to bring the RS 6 Avant to the US. Boy am I going to have a hard time passing that one by. The ultimate stealth mobile:)
Anyway, what kind of finish did you use on the Kefs, precat lacquer? Gutsy thing to do.
I have watched several episodes of AMMO. Very informative. I think he is in NYC where there are plenty of megabuck cars for him to work on. He drives a 911 on track. Smiley has the cup car nose and wing. I have had him on track several times. Rudy is too scary for that. He goes beyond my capability real fast. 
Stereo5 they are always going to say that for liability reasons lest you use something like brake fluid on em melting the finish off. Trust me on this one, an instant detailer like Meguires 34 which is mostly distilled water will do an excellent job, not harm the lacquer at all and leave you with a nice shine. I use it on my subs all the time. 
 

Jeez.....it's not rocket science folks.  The speakers are not outside,  they will not have any bonded contaminants.  So DON"T use clay.  Use some Mequiars Ultimate Quick Wax and a quality microfiber.  That's it. Polish in the same direction....back and forth, not circular.  You won't see swirl marks unless the sun is reflecting off them through a window.  It's paint and basic paint care is pretty simple on a new finish.