I have a pair of Revel M20 speakers that must be at least seven years old now. Lately, and progressively, the sound from my system has begun to strike me as colorless, indistinct, lacking clarity, "blurry" for lack of a better word. Nothing you can quite put your finger on. No obvious distortions. Just not "there" in the same way it used to be. I'm aware this can be a psychological phenomenon. New speakers can enchant with you everything they're doing right, and only later does disenchantment with everything they're doing wrong begin to set in, and grow worse over time. So that might be at work. But I'm also wondering if it can be that the speakers just physically aren't what they once were. Do speakers deteriorate in subtle ways, so that you can't point to an obvious malfunction yet they are simply failing to convey music in the way they once did?