@freediver wrote:
I have speakers that had manufacture periods starting in late 2012(Harbeth M30.1)& 2014(Dynaudio Excite X14)..Both are low hours usage & it’s likely neither is over 300-400 hours use..
Speakers usually don’t degrade with accumulated use (unless mechanically and thermally pushed to or beyond their limits in a regular fashion), and you could even argue to the contrary. One aspect is running in the speakers mechanically (drivers) and electrically/chemically (crossover), but maybe there’s some merit to the expression of "burn-in;" some metal parts of the drivers close to the magnet and voice coil - disregarding the magnet itself - will benefit (the sound from the speakers) from being demagnetized to the exposure of sufficient heat created by the voice coil. From thereon it seems the more frequently the speakers are used (again, within their limits), the better, not necessarily to say they’ll get increasingly better from this point forward (i.e.: after being properly run in), but rather that they’ll will maintain their level the best - not least mechanically - from regular use. Some foam surround types do seem to degrade with movement (i.e.: excursion) as well as from the exposure to UV-radiation and atmospheric conditions, but more modern polyether-based foams last decades, and when treated with foam guard are very resistant to UV-radiation and other external factors. In your case I wouldn’t worry; keep ’em playing, be mindful of exposure to UV-radiation (that is: direct sunlight) and extreme temperature and humidity conditions, and enjoy the music.