View Full Version : Manditory Reconing?

09-23-2006, 07:18 PM
Hi, I am new here (just throwin that out there) and I bought a basically mint condition pair of 4311's. They were from the original owner, and he never reconed them, he says they sound great, but I read JBL says you should recone them ever 12-15 years. My dad has a pair of 4310's that were reconed by my uncle, and the cones and the flexy stuff that attatches them to the outside look identical to the pictures of mine. So simply, i suppose i want to know, if leaving my speakers with the original cones, will i be missing out on the full JBL experiance haha?

09-23-2006, 07:24 PM
No. They're fine. Accordian surrounds.

Drivers with foam surrounds may need them replaced every 15 to 20 years.

Not yours....

09-23-2006, 09:43 PM

09-23-2006, 10:48 PM
I've heard it's the air pollution that does it. Guess yuu would have to put a pair somewhere with no air pollution for 20 years to know. I've got a pair of flairs with the foam intact. Are they the only pair of speakers with white foam left. Does todays foam change their sound. I'm not repairing them before they're broken but I'm curious. Seems like a lot of people would know.

09-29-2006, 09:40 AM
Apparently, it's the floating microbes/bacteria in the atmosphere that degrades foam surrounds. Same process as dry-rot in fabric. This is why it seems to happen more in humid climates... more "advantageous" environment for the bacteria...

The newer poly-ether foam surrounds have much more resistance to bacteria attack, than the older poly-urethane foam surrounds. Should last much longer, after being refoamed, these days.

However, as was stated, the 4311/4312 woofers have doped fabric surrounds... unless they get ripped or baked, they should last virtually forever...