Possible way to audibly hear changes from Burn In

[Shadowfax]

I was thinking recently, after hearing that a new Esoteric K03X needs 400 hours of break in time. That's a long time to wait to hear a change, and I am sure that after that many hours, most people would not be able to remember what it sounded like when first fired up.

So my theory is, if you setup a system in a dedicated room and placed a recording device on a tripod in the room, you could record a track played back. Then after 400 hours, play and record the same track again.

1- if there is an audible difference, you should be able to hear it between the 2 tracks played back?
2- if there is any difference, wouldn't the 2 wave files show a difference?

In theory, this sounds like it could be a valid test, but I don't recall seeing this kind of test done to prove changes in sound than can be audibly heard.

Thoughts and reasons why you think this would work or not work.

 

[the professor]

I've never tried that but I have over the years had the chance several times to hear a broken-in piece in a store and a new out of the box piece side by side.

 

[Shadowfax]

I've never tried that but I have over the years had the chance several times to hear a broken-in piece in a store and a new out of the box piece side by side.

Was it better, worse, or just different?

I got to thinking about this because there is always a heated discussion as to whether it's real or that your ears get used to something different after 400 hours. If this test worked, it could be proof that break in is real.

 

[the professor]

It was always different. Some more than others.

Seemed like most things - Amps, DACs, speakers - get in the ball bark (95%) of their broken-in counterparts after 2-3 days of running 24/7. So 50-75 hours.

Seemed like pre-amps took the longest to really bloom into their broken-in best. Obviously I was hanging out in the store way too much.

 

[Speedskater]

There will be so, so many uncontrolled variables that the test will be meaningless. Mic & speaker setups lack the resolution needed to see differences in the electronic equipment.

Make a digital recording of the output of the Esoteric K03X, then make another recording 10 minutes later. Take notes about what hi-fi equipment is on also appliances, hi-tech lighting and HVAC. Also note the exact setting of everything in the hi-fi system and the placement (dress) of the power & interconnect cables. 400 operating hours later make another recording, then compare all 3 recordings.

 

[Shadowfax]

A user on another forum just came up with a better more reliable way to do the same thing. I guess the big question is why don't MFGs do something similar in order to prove that their product needs breaking in, and that there will be a measurable and audible difference between before and after? Wouldn't that just put an end to the whole break in argument?

"You don't even need a recording device on a tripod in the room -- simply record to .wav files directly from the line out on the player. You'd want to use studio-grade recording equipment for this. Then digitally invert one recording and sum both recordings together. The output is the difference between the two recordings.

I'd first make two recordings immediately after each other and compare them as above to establish a baseline difference -- which I'd expect to show no difference beyond inevitable low-level background noise -- prior to doing the 400 hour break-in."

 

[Shadowfax]

There will be so, so many uncontrolled variables that the test will be meaningless. Mic & speaker setups lack the resolution needed to see differences in the electronic equipment.

Make a digital recording of the output of the Esoteric K03X, then make another recording 10 minutes later. Take notes about what hi-fi equipment is on also appliances, hi-tech lighting and HVAC. Also note the exact setting of everything in the hi-fi system and the placement (dress) of the power & interconnect cables. 400 operating hours later make another recording, then compare all 3 recordings.

My theory is that nothing in the room is moved or changed between recordings aside from the CDP playing a disk for 400 hours between recordings. That would eliminate many of the variables you mentioned.

 

[Speedskater]

Hard to keep all humans out of the room for 2 weeks. Then there's humidity & heat and other uncontrolled variables to deal with. The people that do serious ABX tests complain about uncontrolled variables and they don't use microphones.