break-in--bane or boon ??

Doug, I thought that your article was excellent. Which is not say that I deny that all or even most claimed breakin phenomena are real. But I strongly second your basic theme that the only way to know for sure is to compare two identical cables or components in the same system at the same time, with one of them having been broken in, and one not.

I would further emphasize and/or add a couple of thoughts:

1)In addition to the possibility of user acclimatization, and the vagaries of aural recollection, it seems highly expectable to me that over the course of 300 hours of use sonically significant changes will occur that are unrelated to the cable or component being assessed. Aging or ongoing breakin of other system components, changes in AC line voltage and AC noise conditions, changes in RFI/EMI conditions, record wear due to repeated use, even seasonally-related changes in room temperature (temperature being a parameter that is fundamental to the physics of transistors and other semiconductors, for one thing). Again, as you indicated, the only way to rule out those kinds of possibilities is by direct comparison between identical items that are at different states of breakin.

2)I would expand your disclaimer about speakers being a special case, to which your article doesn't necessarily apply, to include all transducers (i.e., speakers, headphones, and phono cartridges), and also tubes.

As a point of interest, the most notable, extreme, and repeatable example of breakin that I have experienced is with my Stax electrostatic headphones. If they are not used for a period of a few weeks, which happens occasionally, there will be a day-and-night deterioration of their sound quality, that is instantly recognizable on most music. It can be corrected by having them play highly compressed rock music for a couple of hours, at volume levels that are higher than I would dare use if the headphones were on my head. That has been a consistent and repeatable phenomenon throughout the 25 years or so since I purchased them new.

Regards,
-- Al

09-06-12: Nonoise
The changes I've heard during break in usually take me by surprise. I'm not expecting it, it just happens. My brain is in its usual auto mode when I hear the difference. It's when I'm listening for listenings sake. Nothing scientific here. This is with recordings I'm very familiar with. It's like I'm being tapped on the shoulder (ear). Subtle, yes, but noticeable.

That's when I focus my attention. That's when I break out other familiar recordings to see what else parallels what I'm hearing, or compliments with other areas of improvement. This is usually followed by one or two more levels of improvement, over time, and then no more.

It's something I've come to expect but not anticipate.

But how do you know that you are not, on a significant fraction of those occasions, attributing the change to the wrong variable? And that the change is not actually due to one of the several different kinds of extraneous variables I listed in my earlier post in this thread, or to tube aging, or to the kinds of variables you and others have been discussing in this thread, such as changes in humidity, differences in the power levels of AM radio transmissions during the day vs. the evening, changes in power quality, etc.

Not to mention, as indicated by me and others above, some degree of change in the breakin status of transducers that can occur and re-occur periodically, depending on how frequently they are used and also perhaps on what they are used to play.

And doesn't it also stand to reason that once your attention has focused on a perceived change, and you then "break out other familiar recordings to see what else parallels what I'm hearing, or compliments with other areas of improvement," that in doing so there is an increased likelihood that you will perceive things that may have been present in those recordings all along, but you were not previously as conscious of?

I'm certainly not saying that ALL perceptions of breakin-related changes of cables or electronic components are being attributed to the wrong thing. But my point is that without a methodology that includes the kind of disciplined comparison Doug has described, it is all too easy for that to happen. Ultimately resulting in belief systems evolving that are self-reinforcing as well as misleading.

Best regards,
-- Al