Need to repair rotten foam -- any suggestions?

[Guest Wild Turkey]

I recently acquired 18 NIB Blaupunkt 5" woofers that I'm hoping to build into a line array.

Problem is the foam is in bad shape -- rub it with a finger, even lightly, and it crumbles or smears. It feels soft, not gritty and dried out.

Is there anything I can coat/soak the surrounds with while they're still intact without the hassel of complete surround replacement?

I don't expect to drive them very hard, but you know how it works!

thanks

(Oh yeah I've got about $5 each in them!)

[dynaco_dan]

>I recently acquired 18 NIB Blaupunkt 5" woofers that I'm

>hoping to build into a line array.

>

>Problem is the foam is in bad shape -- rub it with a finger,

>even lightly, and it crumbles or smears. It feels soft, not

>gritty and dried out.

>

>Is there anything I can coat/soak the surrounds with while

>they're still intact without the hassel of complete surround

>replacement?

>

>I don't expect to drive them very hard, but you know how it

>works!

>

>thanks

>

>(Oh yeah I've got about $5 each in them!)

Hi there;

What you have is called "foam rot" and yes it does mean you will need to replace the foam surrounds, if that size surround is available.

Looking at a profile view of the drivers, measure the Outside diameter and the Inside diameter, and note the make and model of driver and contact a major surround dealer on the internet.

There is nothing you can do now that will make them usable for even a short while.

The Bose 901's drivers require refoaming as well and any kit you can buy should be about the same price with 18 drivers.

I believe Bose originaly used a CTS fullrange driver and had a cloth surround.

Later they produced their own drivers with foam surrounds.

Philips had a midrange driver with it's own plastic enclosure many years ago and it may or may not have been adaptable for this type of setup.

The Bose uses an electronic equalizer to shape it's response and compensate for driver limitations.

Options are, price new foam kits, if each driver is sound to begin with.

Evaluate that fact before spending any money.

Price new equivalent drivers.

Shop on ebay for Bose drivers.

Good luck with your adventure and please keep us informed as to your decisions or more questions.

Other ideas will come forward as other members read your question.