One of the pair is minutely louder and seems to play slightly more pronounced. The affected one has a slight rattle around the woofer at certain frequencies (I believe it's likely the washer that I've seen talked about in other places) it also has a slight 'tweeter' buzz coming from the top right driver in some upper crunchier frequencies. All drivers are visually completely fine and are void of any visible damage. Might this be a crossover (old capacitor) issue?