My speakers catch the morning sun. I'd say that they get at least 4 maybe 5 hours or sun each day. I haven't noticed anything "strange" with the finish.
I haven't cranked them up yet (real loud), so I don't know what they will really do.
The Rat.
M80s, VP-150, QS8s,
SVS PC 20-39+, OPPO,
Onkyo 703s, Harmony 880
Sony 60" SXRD HDTV