Speaker Break-In - What Physically Changes During Break-In To Enable Better Sound?

There seem to be two issues being mentioned.
First is NEW speakers/crossovers/ electronics needing time to settle or work into the better sound. Speakers in particular the cone speaker surround, for Magnepan the mylar needs to stretch a little, and all need capacitors in crossovers to break in.

Second is the apparent getting better after turn on of many components.
I agree with both happening.
Anyway, I leave all my stuff on 24/7 to avoid the warm up hour.
(I am retired and listen all day every day anyway)
The one component I leave turned off  still does take about an hour to sound better. (Preamp I have I use only for LP playback)

@kosst_amojan

Did you watch the videos?

You might learn something if you did.

Not all speakers are just thrown together using OEM parts and go out the door with only a go no go test. Some drivers are rigorously built and stress tested individually (extreme amplitude response as well as thermal) and tested against an “ideal response” reference and tested again together in the final assembly. These speakers are already broken in when you receive them. Drift over the life of these speakers is negligible due to the entirely different design philosophy to other manufacturers. We are talking true reference type speakers (with commensurately costly manufacture process) even if the word “reference” is way over used to market nearly every speaker.

True reference is not a “silly” concept it is however expensive and very few speakers are built to such a high standard and this is why many low quality manufacturers will warn you that their device needs to settle and break in at your home for up to hundreds of hours.

.... We are talking true reference type speakers (with commensurately costly manufacture process) even if the word “reference” is way over used to market nearly every speaker. True reference is not a “silly” concept it is however expensive and very few speakers are built to such a high standard and this is why many low quality manufacturers will warn you that their device needs to settle and break in at your home for up to hundreds of hours.

I’ll agree with you @shadorne that the term REFERENCE is used a bit loosely in the case of audio gear.

In my case, I have Golden Ear Triton *reference* speakers. I certainly knew prior, during and after purchase that in the context of the "absolute pinnacle of best possible performance", the speakers would NOT match a "reference" criteria, despite the use of the word "reference". Same can be said for my Emotiva ERC-3 CD player, which has the label "reference" printed on the face of the unit. However, I would expect "very good to better than very good performance, and exceptional value with respect to what TRUE reference would mean/cost".

The aforementioned stated, neither of two manufacturers recommends any kind of extended break in period. In the case of the speakers, Sandy indicates the crossovers, capacitors and mechanics of the drivers needs a little time to "heal", and we are speaking of approximately (only) 50 hours of usage.

In fact, in the case of the speakers, I have good reason to believe that Golden Ear DID consider a TRUE reference product (speaker), however, "cooler heads prevailed" when they determined that the cost to the consumer would be in the 80K/pair range.

Some caps need as little as 50 hours. It depends on the construction design and physical size.  For example,  Jantzen Superior Z caps need only 50 hours, however Duelund copper foil (PIO) caps need all of 500 hours.  Just the way it is.  

shadorne..Disagree with your assessment on burn-in. In the Spring of 1994 I purchased a used pair of Camber 3.5ti's from a member of the Washington Audio Society. At the time I had a Carver system and one of the two very best CD player's from Denon. Several day's after purchasing, I settled down for a long listening session, and was ticked off since one of the woofer's had severe break up and distortion at low frequencies. The titanium tweeter and woofer were from SEAS. I called the seller and he admitted the first day he had them, he drove them very hard with a low powered tube amp and a high powered solid state amp.
I took the speaker's to a speaker repair service company in Bellevue and was told the piston was damaged and the woofer had to be replaced. The cost of the woofer and repair came to $115.00 and the seller refunded the cost for repair. For those who plan to put speaker's in storage for an extended time, store the speaker's face down. Since the piston is suspended hanging off the back of the cone, the piston will sag if inactive for several years and storing them face down will keep the alignment perfect.