Rejuvenate old SEAS Drivers?

[CliffR52]

Thanks Galu.


Excellent reference (blackcones).


The enclosures had fibreglass batts.
Not the nicest thing to have but as the boxes are sealed there's no port from which fibres can be blown out of.


I restricted doping to the surrounds only avoiding the cones themselves.
While doing it I found four distinct straight line tears in the surround of one of the drivers.


Two coats seem to have provided enough material to stop loss of air.
I'm doing some finishing touches on the crossover before I can assemble the second enclosure.


I hooked up the first enclosure and was satisfied with its performance from the little I play through it.


I prefer to wait until I have a pair before doing any more listening.


Your input has been invaluable to me.
This forum is a treasure of experience waiting to be uncovered.


Once again, thanks.


Cliff

[CliffR52]

Originally Posted by Galu

Just in case you missed it in post #14, here is the link which gives all the details of your 21 TV G drivers: BLACKCONES

Thanks G.

I finally completed the crossover refurbishment and the woofer doping instead of a radical refoam.
These speakers are really nice to listen too.


Only critical point:
At a high but reasonable volume for bass and treble I found the high notes are almost painful to the ear.
At this volume the tweeters aren't breaking up but just too loud for comfort.


Without resource to measure, could I conclude that the response is too great at the higher frequencies?

I'm using an old Marantz PM-6a Amp but would also like to try the Interdyns on other Amp to verify that it's not the Amp.

If they are too loud, would I compensate by adding a resistor before or after the Cap?


Thanks


Cliff

[Galu]

Assuming the tweeter is nominally 4 ohm like the main driver, you could experiment by placing a 1.5 or 1.8 ohm resistor between the capacitor and the tweeter.

This will result in around 3dB of attenuation and will allow you to judge if your problem indeed lies with the tweeters being over sensitive.

[Stanislav]

It could be also that the Blackcones top end is very hot, hence the sizzle.
Maybe run them, as a test, without the tweeter, and listen.
You may need to tame their part of the xover to achieve a better balance.
1st order series xover might be a good choice in this case.

[Galu]

Good advice from Sanislav there. Disconnecting the tweeter would be an easy way to attenuate it for experimental purposes!

The Blackcone is said to roll off smoothly after 5 kHz with a single break up at 8kHz. It's possible that it could benefit from some high frequency filtering. That's what Stanislav means when he suggests a 1st order series xover.

I can help you with that if if necessary.

[CliffR52]

Thanks Guys.


Great advise.



I'll start by disconnecting the tweeters and listed for the high end issue.


If this disappears then I'll experiment with resistors.