What transducers and under what controls and test parameters?
Temperature and humidity "significantly" affect how speakers perform? How much change in temp and humidity? I would posit that it would need to be dramatic as compared to a normal living room conditions to have a significant effect. Have you measured this and under what controls and paramaters?
Transducers built with quality components, and quality crossovers or self amplification should under no circumstances take "months" to stabilize. Don't think that's arguable on a scientific forum.
I agree with the rest. If you're proposing that room eq measurements prove speaker burn in and significant response to atmospheric conditions, I'd say there are other reasons for inconsistent results. Makes me wonder if Amir is tightly controlling these factors in his garage using his Klippel... don't remember mention of it. If its 30 degrees that might be something, but even then I'm skeptical of significant change.
Change my mind...
I'm not really into the debate thing. There is literature you can find online along with the relevant mathematical formulas to calculate room expansion and contraction as well as the thermal expansion of the speakers. The physics of humidity affecting sound is also well researched. I haven't written the scientific papers myself, but people with fancy PhDs have. Not that having a PhD in these types of things automatically means they are correct. But it does mean they studied a lot.
Sorry for not doing the search for you and giving you a bunch of links. I don't have the energy for that.
My experience with this is in professional sound reinforcement for venus and monitoring for broadcast. Since none of these conditions are lab conditions, I can't give you the precise controls etc. I'm just telling you what is somewhat common knowledge among people in my line of work. I spoke to a sound engineer who, due to the construction materials of the venue he managed, measured a thermal expansion in the room dimensions of near 10in or so if I remember correctly. And this caused quite a bit of trouble for him with resonances and standing waves that seemed to change every time he turned the system on.
I am not sure how you came to the decision that speakers do not burn-in, and depending on the construction, there may be some that don't. I imagine AMT drivers probably experience almost no burn-in, but I have not measured them to know for sure. Dynamic drivers all seem to experience burn-in or break-in from my experience. I have not measured any planar drivers, but Dan Clark headphones are notorious for changing the most dramatically due to the pleated design of the driver. The dimensions change so much that he actually has to run them for many hours before driver matching and even then users still experience a bit of change in the sound. But once they settle, they are very stable. Balanced armatures seem to experience no burn-in. Electrostatic drivers I am unsure of but probably do not break-in. And regular (un-pleated) planar drivers are probably also quite stable out of the box, but I can't say for sure. I will say that I have not personally experienced burn-in with my dynamic driver headphones, but I most definitely have with speakers in rooms that are kept at a mostly stable temperature and humidity and have no exterior walls that might experience abrupt thermal changes from weather.
And this isn't a couple dB at one or two frequencies, this is huge changes of up to 8dB difference at it's most extreme.
Sorry if you really wanted me to change your mind and put forth some strong points to build an argument. That's not something I care about.
Oh, almost forgot. Danley and Presonus are the brands of the speakers. The Danleys have been very stable since day one. The Presonus on the other hand are the ones that changed dramatically after several months of use. It was very gradual, so I didn't actually notice the change. It wasn't until we did a system-check using an Earthworks M23 that we noticed the frequency response had changed. Other changes on different speakers have been very subtle, but at least this one was not.
Again, my memory failed me. I just remembered. We also ran a jbl system and some Renkus Heinz monitors. I didn't experience any significant change with the Renkus Heinz speakers, but they were heavily used when we purchased them. The JBL system did experience some very noticable change, but this seemed to be because the system was almost 20 years old and the drivers were starting to fail. Most noticably, the tweeters were gradually losing response above 10kHz. The tweeters had been replaced once before.
And no, I do not want to enter a debate about if driver failure is real or not.