Recommendation all-rounded speaker (small room)

That sticky stuff on some drivers is a dampening material, like a tar if you will, that is used to improve the driver response.  It is tacky on purpose, as you sort of paint it on the cone.  You cannot clean it- dust is a problem-but fortunately dust doesn't affect driver performance.   So best not touch it.  

TO fix it cosmetically, you have to recone the driver (start over with fresh parts and fresh dampening material) or replace the driver.  Both are not cheap.  If it bothers you, then Id get both drivers reconed so they look the same.  Use an air cleaner (not an ozone generator which destroys rubber) to reduce dust in the room.

Don't beat yourself up, about it, I did it myself years ago before I understood. 

Lone Mountain Audio

Brad 

Windex in moderation, applied first on a relatively lint free soft cloth, a old worn out t-shirt works well. I’ve cleaned my tar stricken drivers with this method since the late 80’s with fantastic results. Hope this helps

Appreciate your advise, not sure how to upload the photo in my previous post was not proper loaded (though I have inserted the URL image and photo size) Nevermind, since it's very minor issue, not going to touch or bother the woofer. I may use air dust blower (camera lens) to blow away the dirt if need be. Thanks again guys. 

Cheers

How are you liking them...to busy probably.They should warn people not mess with them.Are you enjoying what your hearing so far.

Busy on other things 😆,  only manage an hour or two per day.

I am satisfied with the sound , did slight toe in speaker with equalateral triangle from listening spot  due to small room /near field to reduce boomy noise, slight improvement. Will continue to observe and enjoy auditioning familiar tracks. 😉