Speaker refinish

Every year or so I use Scott's Extra Gold Wood Cleaner and Preservative on all my furniture and audio gear wood; never a problem, always an improvement, with regard to luster and color. I'd recommend trying it, being careful not to overly contaminate drivers and other areas not made of wood. The biggest factor, of course, is keeping sunlight consistent on all areas; that will only take time!

So I take it that Proac's "yew" finish is an oil or wax finished veneer ?

Thanks for your recommendations, I appreciate it.

If you leave the grills off, they will darken surprisingly fast. I had the same issue with a pair of Spendor 9/1 speakers. They looked even after about 6 weeks of normal light exposure.

Even if Steveaustin's ProAcs weren't an oil or wax finish, an oil would have penetrated through the sides of the cracked veneer. Veneers with tiny little knots (like some Yews) or burls have a distinct tendency to craze & crack over time. Once the surface is broken with a crack, then oils can get in and do their thing. As Lars says, things like Scots do make wood look pretty. But, it's just a surface film that doesn't penetrate most wood finishes. Furniture polish manufacturers tend to suggest their products can accomplish things that are unlikely, such as nourishing wood. Rather like the implied promises of women's cosmetic moisturizing products :-)

I had a pair of Proac Response 1.5s in cherry finish with same problem. I left the grills off the entire time I owned them and never noticed any improvement. When I sold them the difference in the finish was noticeable in the pics.