Why no “Break in” period?

@andy2 

you state: "Metals are good heat conductor because mostly of free electrons carrying kinetic energy (heat). Car engine breaking in is possible because of friction and heat. And of course electric current in cables is carried by electron which generating friction and thereby generating heat."

you are a little off in the fact here.  1) electric current does not generate friction.  Friction is a mechanical phenomena.  (elementary physics).  Electric current can produce heat via resistance and inductance.  But this is not friction.  Friction is mechanical resistance to slipping.  like a tire slipping or not slipping on the road. 

now, I agree, regards burn in that the changes observed fall into two categories: one: mechanical or chemical changes.  Speakers have moving parts.. hence mechanical.  And capacitors have capacitance based on chemistry.  And chemistry changes over time.  two, far more subtle changes in electronics which are smaller (yes, chip sets age).  Changes "heard" from aging of wires... would be much much smaller... tiny really.

Finally, if a change due to burn in can be heard... then it can be measured.  PERIOD.  Measurement tools available are far more sensitive and have far greater bandwidth than the human ear.  Even if you are an expert listener like millerC or Michael G.  Sound waves are a physical thing propagating through air (sound does not propagate through a vacuum) and they can absolutely be measured.  

if you cannot measure it (regarding sound changes), then it is probably opinion and swayed by perception bias,

Science.

Now admittedly it is challenging to measure all sound waves and all reflections and all nulls or additive signals in a sound room.  Takes time and is expensive.  So for lack of that investment... our ears are reasonably good.  key word: reasonably.  we are going for pleasure here.  

But if someone claims they can hear something due to burn in.. and if at the same time it cannot be measured.. the it is BS!

Again, we can measure EVERYTHING we can hear, in far greater resolution and precision and accuracy than our ears can deliver.  (note: resolution, precision and accuracy are all different metrics).

In my world, we have to measure and isolate vibrations to a FAR lower threshold than anyone in audio ever experiences or needs.  Orders of magnitude better performance regards vibration isolation than in audio.  Our equipment racks cost 10x up to 100x the cost of the very best audio equipment racks.  We can measure the effects of one foot fall outside the building at 10's of meters away from the building and isolated by the ground, dirt, the building foundations, etc.  (this is a research building with some of the best noise and vibration isolation in the world.)

Measurements.......

John Curl Interview Page 15/18


Also, we couldn’t use mylar capacitors, which are fairly efficient coupling capacitors. While mylars are fairly efficient from a size and cost point of view, we realized they have problems with dielectric absorption. I didn’t believe it at first. I was working with Noel Lee and a company called Symmetry. We designed this crossover and I specified these one microfarad Mylar caps. Noel kept saying he could ’hear the caps’ and I thought he was crazy. Its performance was better than aluminum or tantalum electrolytics, and I couldn’t measure anything wrong with my Sound Technology distortion analyzer. So what was I to complain about? Finally I stopped measuring and started listening, and I realized that the capacitor did have a fundamental flaw. This is were the ear has it all over test equipment. The test equipment is almost always brought on line to actually measure problems the ear hears. So we’re always working in reverse. If we do hear something and we can’t measure it then we try to find ways to measure what we hear. In the end we invariably find a measurement that matches what the ear hears and it becomes very obvious to everybody.

http://www.parasound.com/pdfs/JCinterview.pdf

"So what was I to complain about? Finally I stopped measuring and started listening, and I realized that the capacitor did have a fundamental flaw. This is were the ear has it all over test equipment. The test equipment is almost always brought on line to actually measure problems the ear hears. So we’re always working in reverse. If we do hear something and we can’t measure it then we try to find ways to measure what we hear. In the end we invariably find a measurement that matches what the ear hears and it becomes very obvious to everybody. "


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even if the only one hearing the change are those with superior hearing like miller carbon or Michael Greene.... if they can hear it.. then it can be measured.  PERIOD.

Our instruments are far more sensitive than even the very best ears on the planet.  

This is science fact.  not opinion.  not rhetoric.  not trying to sell you a solution.

sailboat

we are very good at measuring what we know to measure, but are we aware of all variables that need to be measured...and our understanding of human hearing is really not all that great, so what do we correlate our measurements with...

  Eddie,   Speaking for me only.   i hear small %% differences then in three days it's even better