break in period?

[bose301s 5,000+ posts]

And then there are those that don't learn at all...

There are way too many of them here as well.

 

[JohnEJanowitz 10+ year member]

95% of all break-in will occur the first few times the suspension is stretched to it's limits. The main thing you are doing is loosening up the phenolic on the spider. Foam surrounds soften slightly, but not a whole lot. Rubber surrounds don't change much at all. We play all woofers off the line for about 30sec at full excursion to break-in the suspension and also to check for any mechanical noise. You'll notice a shift in Fs from before and after the 30sec tone, but then can play the woofer for an hour and not really notice a further chance. We play a 10Hz tone because it is easily to move the driver with low power at this range and because it's not audible so doesnt' drive anyone nuts. When the next batch of woofers get done in a day or two I'll measure some impedance curves before and after break-in and then play one for an hour and measure again. I'll post them up so people can see what's actually happening.

John