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Drivers break-in beyond a few hours is a golden ear myth with absolutely no supporting data

Ask any driver engineer how long it takes to break-in a driver's spider and the answer will be a few minutes of heavy use (long strokes).

Look at test results for any cone driver and you'll see minor (probably not audible) T/S spec. changes in the first few hours of use. I know of no controlled listening experiments that prove even the real break-in during the first few hours is audible. In 35 years of building DIY speakers I have been able to hear break-in occur only twice, and the effect lasted only for a few minutes (weak bass from two subwoofer drivers).

I use loud RAP music for bass driver break-in. A string quartet at 60dB would take forever. You can actually break-in a woofer by slowly stroking the cone with your hands through the maximum stroke (XMECH) ... but that's risky.

For one example, I have a printed test report of a high quality Seas Excel W21EX001 bass driver with a break-in tone that used only +/-2mm of it's +/-6mm XMAX (not loud enough for fast break-in of a spider) but even then the changes were small and not likely to be audible.

The testing was performed by Philip Vafiadis of VAF Reasearch in Australia (the organization's website happens to be www.vaf.com.au
if anyone cares.

Fs changed from 35.47Hz. to 32.03 Hz. in 60 minutes
and finally to 31.62Hz. after 120 minutes

Qts changed from .49 to .42 in one minute
and finally to .41 after 120 minutes

They didn't measure VAS

Most of the T/S changes typically measured are due to voice coil warm up and will disappear after the voice coil cools off the next morning. But VAF Research wisely let the voice coil cool off every time before measurements.

The break-in may have already been accomplished in the speaker factory during quality control testing.

Speaker designers John Dunlavy and Paul S. Barton (PSB Speakers) have written essentially the same thing in internet posts.

The belief in the need for 100's of hours of break-in is golden ear nonsense. But then golden ears are not a very scientific group of people -- they thrive on beliefs. They will never provide data to prove their break-in beliefs, because such data do not exist.

Fortunately this 100's of hours break-in belief is a harmless belief, but may actually be useful for the wrong reason -- it may take your ears 100's of hours to get used to new speakers. And in the end, the only way to prevent break-in, would be to leave the speakers in their cartons and never play them!



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