by vtshopdog Wed Mar 16, 2016 7:43 pm
Wood Nerd stuff is kinda up my alley First, whatever you decide to do, try it first on a small hidden test area!! Sometimes things don't go the way we plan.
Unable to view a photo I'll assume you have either a water mark or a darker area protected from sun fading. How to mitigate will depend on your original finish. If you want to avoid doing a full refinish you could try a product like Tung oil or Watco Danish oil. You will likely end up having to do both speakers as they probably won't match after your apply oil to one.
I wet sand Watco all the time, try 400 or 600 grit. Basically flood the surface, wet sand, leave for 10-15 minutes then wipe off with a rag. The material removed from the wood by sanding will blend with the oil, smear around the surface and sort of mix the colors together. This likely will not fully remove your spot, but it will be less visible. If its sun faded, a but of UV exposure will catch it up to the rest of the wood.