Drivers stored wrong for 15-20 years

Skiivari · 27th October 2011, 08:54 PM

Found a pair of drivers that were meant to be used in an old full range speaker kit and having found out the parameters they seem quite nice for a horn sub I've been dreaming of. http://www.seas.no/images/stories/pr..._datasheet.pdf

Anyway they're in really nice condition externally but storage in cold and humid conditions combined with apparently having had the cone pushed in during this storage has resulted in the spider being stuck in a position that isn't in the middle... They move nicely but the travel inwards is much shorter than outwards.
Is there anything I can do? I've been running them for a few hours with a 20hz sine wave on low level but it hasn't made a difference.

-Artturi

freddi · 27th October 2011, 09:42 PM

could you try weighting the cones from the rear with mortite (if it would stick?) and gently drive them with sine with the cones facing down?

sofaspud · 27th October 2011, 10:18 PM

An unusual situation, and I don't know how an expert would approach the problem. I'm thinking that low level 20Hz wouldn't be as helpful as just exercising the spider with a higher level music signal, maybe directing steam at the spider before that is done.

revboden · 27th October 2011, 10:45 PM

replace the spider and surround. Steam heating the spider may melt the glue or deform the cone.

Ron E · 27th October 2011, 10:52 PM

freddi's suggestion seems reasonable and worth a try before reconing them

Moondog55 · 27th October 2011, 11:16 PM

Mount them in a baffle FACE DOWN and play bass for a couple of hours and see if it helps??

Andrew Eckhardt · 27th October 2011, 11:54 PM

A couple volts DC to push the cone in the opposite direction wont hurt the driver, but if you use the exact same corrective force it might take 20 years.

NEO Dan · 29th October 2011, 02:09 PM

Hair dryer and sine wave while inverted, but gently.

dirkwright · 29th October 2011, 03:20 PM

Did you ask the manufacturer?

Skiivari · 29th October 2011, 06:27 PM

First of all, got the link wrong, but they're 25F EW's even though it doesn't make a difference.

I've been driving them with sine and music at decent levels but the spider still returns to an offset location..
I just jammed one driver with a toilet paper roll (carefully) and I don't think it will help on its own but I might as well try giving it some heat. They are virtually unusable in their current state but I have nothing to lose.
I doubt SEAS will have any reconing kits or can help at all because this driver is listed in their "Very old vintage drivers"...

Will report back if I make any progress!

27th October 2011, 08:54 PM	#1
Skiivari diyAudio Member Join Date: Sep 2011	Drivers stored wrong for 15-20 years Found a pair of drivers that were meant to be used in an old full range speaker kit and having found out the parameters they seem quite nice for a horn sub I've been dreaming of. http://www.seas.no/images/stories/pr..._datasheet.pdf Anyway they're in really nice condition externally but storage in cold and humid conditions combined with apparently having had the cone pushed in during this storage has resulted in the spider being stuck in a position that isn't in the middle... They move nicely but the travel inwards is much shorter than outwards. Is there anything I can do? I've been running them for a few hours with a 20hz sine wave on low level but it hasn't made a difference. -Artturi

27th October 2011, 10:18 PM	#3
sofaspud diyAudio Member Join Date: Nov 2005 Location: San Antonio TX	An unusual situation, and I don't know how an expert would approach the problem. I'm thinking that low level 20Hz wouldn't be as helpful as just exercising the spider with a higher level music signal, maybe directing steam at the spider before that is done. __________________ It is error only, and not truth, that shrinks from enquiry. - Thomas Paine

27th October 2011, 10:52 PM	#5
Ron E diyAudio Member Join Date: Jun 2002 Location: USA, MN	freddi's suggestion seems reasonable and worth a try before reconing them __________________ Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan Science is a way of thinking much more than it is a body of knowledge. --Carl Sagan

27th October 2011, 11:16 PM	#6
Moondog55 diyAudio Member Join Date: Jun 2007 Location: Norlane; Geelong: Victoria: Australia	Mount them in a baffle FACE DOWN and play bass for a couple of hours and see if it helps?? __________________ QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"

29th October 2011, 02:09 PM	#8
NEO Dan diyAudio Member Join Date: Jun 2008	Hair dryer and sine wave while inverted, but gently. __________________ Regards, Dan


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27th October 2011, 09:42 PM	#2
freddi diyAudio Member Join Date: Aug 2005	could you try weighting the cones from the rear with mortite (if it would stick?) and gently drive them with sine with the cones facing down?

27th October 2011, 10:45 PM	#4
revboden diyAudio Member Join Date: Feb 2011	replace the spider and surround. Steam heating the spider may melt the glue or deform the cone.

27th October 2011, 11:54 PM	#7
Andrew Eckhardt diyAudio Member Join Date: Nov 2005 Location: PA	A couple volts DC to push the cone in the opposite direction wont hurt the driver, but if you use the exact same corrective force it might take 20 years.

29th October 2011, 03:20 PM	#9
dirkwright diyAudio Member Join Date: May 2011 Location: Virginia	Did you ask the manufacturer?

29th October 2011, 06:27 PM	#10
Skiivari diyAudio Member Join Date: Sep 2011	First of all, got the link wrong, but they're 25F EW's even though it doesn't make a difference. I've been driving them with sine and music at decent levels but the spider still returns to an offset location.. I just jammed one driver with a toilet paper roll (carefully) and I don't think it will help on its own but I might as well try giving it some heat. They are virtually unusable in their current state but I have nothing to lose. I doubt SEAS will have any reconing kits or can help at all because this driver is listed in their "Very old vintage drivers"... Will report back if I make any progress!

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