crossover "break in" time? (Off Topic)

by GC, Tuesday, March 20, 2007, 05:50 (6247 days ago) @ MikeH
edited by GC, Tuesday, March 20, 2007, 06:00

I can understand why drivers need to be broken in, the materials need to be
worked/fatigued a bit to allow the cone to move easily.
I have been an electronics technician for over 15 years, "Breaking in" of
crossovers and filters has me completely baffled.

"Burn in" as used in the electronics industry is mainly for detecting
faulty components, if something is defective it usually completely fails
very quickly. You work the device hard for 24 hours or so, if it doesn't
go bang it will probably last for the warranty period so you box it up and
sell it. I am interested in "Break in" not "Burn in"

Nothing will change in a well made inductor or resistor, I can only assume
it is a chemical change inside the capacitors. If this is the case I expect
they will sound good for a while then continue to "break in" until they
stop working properly.

I've been searching on the internet and can only find Salesman style
explanations. Logical technical explanations are hard to find.

I accept something sounds better after being used for a while, I want to
understand exactly why.

Can someone point me in the right direction please?

Mike

I have a couple of views, but they are far away from scientific, and concerns capacitors only.
(Eventhough we might compare a cable with a cap and a coil as well. (Small values though))

I have noticed that "aged" capacitors sounds "different" from new ones. That made me once many years ago think that some materials acts like red wine, cognacs and whisky etc. which gain quality over years, to a certain point at least. It undergoes some chemical changes.
Opposite results with fresh vegetables etc. though. :shame:

I tried, instead of letting my amps pump current into cross-overs over long periods, to give them some juice before soldered into the filters.
I took a vario AC trafo and connected the caps, turned up to certain value, close to their max. spec's, so that I almost could hear them cracking. Just a few seconds or so.

That made the same sound "difference" as aging, but done in a second.

Now another, maybe more understandable thing, is the trick to "bias" caps in a cross-over filter.
You take two caps connected in series instead of one. (Double the value of course). Insert a battery (9-40 VDC) in series with an 1MOhm resistor between the the center point between the caps and ground.
This bias loads the cap with a constant voltage and the sound is again "different".
The theory is of course that the the signal-electrons should not "drag" the tourgue hidden in the charge/discharge of the cap while playing music. (?).

JBL uses this "tweak" in their Everest and K projects.

In my terms of "different" I have not said anything about if all this sounds "better". You judge. :wink:

PS! I can not help thinking about good old passed away Mr. Kondo, who supplied the expensive Audio Note cables once upon a time. He had from his surplus of stock kilometers of cables collecting dust on the shelfes for years. These aged cables now sell for an outragious sum of money, claimed souding better than new ones.....Religion and beleives?

GC

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