BNS 242 parts replacements?

[Karl vd Berg]

Gentlemen,

I got a pair of these BNS 242 speakers for free the other day.

Not sure if the woofers worth to be repairable, I'd rather go for a pair of new 8" woofers, but............. ???

The tweeters are still brilliant!

I saw this 8" Carbon Fiber Die-Cast woofer and it seems to fit perfectly where the old woofer is now.

Any other suggestions? Many thanks.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[PeteMcK]

re:"seems to fit perfectly" - the electrical parameters are what must fit... They're probably SEAS drivers, take one out & let us know if there is any part code on the back

 

[Karl vd Berg]

re:"seems to fit perfectly" - the electrical parameters are what must fit... They're probably SEAS drivers, take one out & let us know if there is any part code on the back

Hello!

Yes, woofers are SEAS 21 F-GWB, 8 ohms

 

[PeteMcK]

here an old data sheet from SEAS, probably as close as it gets...
http://www.seas.no/images/stories/vintage/pdfdataheet/h134_21f-wb.pdf
for your replacement driver, I'd try to find a paper cone woofer which has a match for the parameters sensitivity (92dB/m) & Qts (.38), although the crossover can be tweaked so the tweeter sensitivity matches.
CA21REX might be close enough...
http://www.seas.no/index.php?option=com_content&view=article&id=174&Itemid=169

 

[Karl vd Berg]

Thanks! I'll look for that replacement! 🙂

Or maybe I'll order the rings and try to restore the woofers. The good thing is that they are still measured 8 ohms. The other "weird" thing is that when connected back to the crossover the whole impedance is 22.3 ohms!

 

[PeteMcK]

re:"I'll order the rings and try to restore the woofers" - that's probably the best way to go.
While you're at it, it's a good idea to replace any electrolytic capacitors in the crossover, they dry out over a couple of decades.

 

[Karl vd Berg]

I'll do that and report later! 🙂

 

[Karl vd Berg]

Ok, back to this project. The rings replacement were ordered. Foam rings as the originals were.

The only problem is how to remove the old mix of old foam+glue shown below.
Tried started with one, pretty sticky. I don't want to ruin the already stressed cone paper.

Plus, what kind of glue goes here and any tip on how to hold the new ring until completely glued to the frame.

An externally hosted image should be here but it was not working when we last tested it.

Thanks!