[QUOTE]Not only does one need to consider the long term mechanical break-in of a moving coil loudspeaker, but specifications change considerably due to voice coil temperature changes. That is why prosound companies measure their speakers and obtain T/S parameters after so many hours of hard usage. Technically, you would need to "burn in" (warm up) your speakers every time you use them no matter HOW old they are. They will always go through the warm/cool cycle when used regardless of age. This could be an important consideration when doing a long duration a/b comparisons of two components using the same speakers. If you listen to component "A" first, then "B", "B" might sound different for no other reason than the speakers used for the comparison now have hotter voice coils. If you really want to be picky, you would need to warm up the speaker coils FIRST before doing the a/b comparison to eliminate or reduce the effect of this phenomenon. [COLOR="Red"]Come to think of it, most cable demos I've seen are with a "cold" speaker, and the "lesser" cable is demo'd first. After a few minutes of use, the boutique "zip cord slayer" is put in after - when the system has had some time to warm up!! If they switch back, you're now hearing "A" through WARM speakers, meaning any previous memory of the sound might be obfuscated. (If you go A/cold, B/warm, A/warm you may think you're listening to "A" a second time but it's technically a different iteration all together because of the lack of controls in the experiment.)[/COLOR][/QUOTE] I will add my experience that after a few swaps the differences become harder to spot, if spotable at all... :confused:
