[bhobba]

I have a pair of speakers (ML1 Reference) whose terminals broke and had to be returned to the manufacturer and fixed.

Anyway while they were being fixed the guy that makes them (Mike Lenehan who fortunately is just down the road on the Gold Coast from where I live) had a chance to re-measure them and compare them to when they left the factory.

Guess what - they now measure better - frequency response is flatter - for example a slight about 1db suckout in the the critical midrange is gone - I saw the measurements and can confirm it.

I asked Mike why is that? Well its not the drivers themselves - they break in very quickly. It's the inductors and capacitors.

There have been many threads talking about burn in in general and speakers in particular. You have one side saying its simply people getting used to the sound and the other side saying they can hear clear and audible differences. Well now we have an objective measurement proving its real and not just getting used to the sound.

Thanks
Bill

[*Scotty*]

Bill, how much did the capacitors and inductors change their values and in what directions. That the woofers could break in and affect the frequency response in such a way is easy to see, the crossover parts changing their values and affecting the frequency response is a little surprising.
Scotty

[bhobba]

Hi Scotty

He hasn't measured the values of the parts in the crossover to find exactly what has changed.  However they are very small gauge hand wound air core inductors (12 gauge I think - but don't hold me to it) and Duelund VSF copper capacitors.  Mike from experience knows such take a long time to fully burn in and hears the change all the time.  He thinks its simply the parts settling over time - but hasn't taken the time to measure exactly what parameter is changing eg it is known the Duelunds have a very low DCR compared to other capacitors and it may be a factor.

Thanks
Bill

[Letitroll98]

I asked Mike why is that? Well its not the drivers themselves - they break in very quickly. It's the inductors and capacitors.

This makes some sense, the drivers do break in, they're a transducer, but I'm fine with an expert saying that happens fairly quickly.  The drivers experience most of the stress loads they're going to see in their lifetime right off the bat so I could agree with them settling in 50-100 hours, perhaps less.  I don't think there's any argument from anyone that capacitors break in, some over extended periods.  I'd have to believe that any change in inductor value is from faulty winding or poor insulation.   

[bhobba]

I don't think there's any argument from anyone that capacitors break in, some over extended periods.  I'd have to believe that any change in inductor value is from faulty winding or poor insulation.

The guy concerned has a special rig to break in capacitors - his experience is capacitor break in is very real.  Exactly what changes however is not well understood just like exactly why capacitors sound different is not well understood.  But sound different they do as I have heard on a number of occasions eg I have a DAC with Russian paper in oil capacitors on the output and one with Duelund VSF Copper - that's the only difference and they sound quite different.  The paper in oil is smother and more polite - the Duelunds are more neutral, alive, and fast.

Thanks
Bill