When should a LF driver be re-coned?
I have a couple of 416s alnico Vs in storage. These are in good shape with no tears, etc and they work well. These have been purchased from others during the last 3 - 4 years, so I don't know where they have been for the first 30 - 40 years. My guess is they are circa early 1970s... (light green paint)
Should I consider re-conning these or should I just build VOTT boxes and play them till they are dead?
I've reconed similar drivers at GPA and they have turned out great.
Re: When should a LF driver be re-coned?
They are 15" 416A's. If they play great just play them.You only recone when it is absolutely necessary.. Sagging Cone,Damaged cone,spider,etc... If you are storing them for a very longtime,3-4 years would qualify IMO.Flip them over every so often.. I had a pair that was damaged by leaving them face down for years...I bought them that way and when I measured them they measured very weak (Magnets).And probably why they were sold.When Bill finally figured what the issue was he said from storing them like that for so long the cone pulled the VC out of the gap and while he zapped them 3 times,they still measured very weak,the ( motors).. After recone they were back to factory spec...
Re: When should a LF driver be re-coned?
Quote:
Originally Posted by
Altec Best
They are 15" 416A's. If they play great just play them.You only recone when it is absolutely necessary.. Sagging Cone,Damaged cone,spider,etc... If you are storing them for a very longtime,3-4 years would qualify IMO.Flip them over every so often.. I had a pair that was damaged by leaving them face down for years...I bought them that way and when I measured them they measured very weak (Magnets).And probably why they were sold.When Bill finally figured what the issue was he said from storing them like that for so long the cone pulled the VC out of the gap and while he zapped them 3 times,they still measured very weak,the ( motors).. After recone they were back to factory spec...
Yeh.... I remember that thread a while back. ...glad you finally got them working.... Bill at GPA is a great guy and very knowledgeable.
On another issue, I have a powered 18" sub-woofer (JBL) that is mounted in a cab and it is firing in a downward position. If I remember correctly, it has a foam surround. Anyway, I suppose this design is a future candidate for a sagging cone?
Re: When should a LF driver be re-coned?
Quote:
Originally Posted by
robertbartsch
Yeh.... I remember that thread a while back. ...glad you finally got them working.... Bill at GPA is a great guy and very knowledgeable.
On another issue, I have a powered 18" sub-woofer (JBL) that is mounted in a cab and it is firing in a downward position. If I remember correctly, it has a foam surround. Anyway, I suppose this design is a future candidate for a sagging cone?
I don't know the JBL brand as well.But from what I know they tend to need new foam surrounds every 10-15 years.. They may also have stiffer spiders and surrounds to deal with the effects of gravity,dunno on this one...Do you know what driver is in this Sub ?
Re: When should a LF driver be re-coned?
Quote:
Originally Posted by
Altec Best
I don't know the JBL brand as well.But from what I know they tend to need new foam surrounds every 10-15 years.. They may also have stiffer spiders and surrounds to deal with the effects of gravity,dunno on this one...Do you know what driver is in this Sub ?
****
The driver is a JBL 2245 - 18" sub-woofer, I beleive. ...kicks butt...
Re: When should a LF driver be re-coned?
Yup and recone kits for those if you can get them are Big Money $$$.I think they are like $300-$400. They last 10-15 years and then the foam surround dry rots.Give'r take a year or two.
Re: When should a LF driver be re-coned?
I suspect the weight of the cone pulling down on the spider fatigues it, so the coil doesn't return to "zero".
Re: When should a LF driver be re-coned?
My cones are 58 Years old, And they sound excellent.
Re: When should a LF driver be re-coned?
Quote:
Originally Posted by
cradeldorf
My cones are 58 Years old, And they sound excellent.
As long as rotated occasionally, they can. But downward facing means the weight of the cone is constantly pulling on the spider. We've been referencing that.
Re: When should a LF driver be re-coned?
Quote:
Originally Posted by
Altec Best
You only recone when it is absolutely necessary.
+1
Bill @ GPA offers the same advice. When it comes to cones, if it ain't broke...