Vandersteen Acoustic Coupler Fix (Vintage 2C's)


This is more of a sharing, experience and fix for people who might be able to benefit from my experience and fixing this problem.

Short background: I own a pair of Vandersteen 2C’s that I bought new in 1988 (one owner). In 1997 I sent the couplers to Vandersteen for a refurb (dangerous system configuration, would slam the drivers to full throw if not powered down correctly, which happened a few times too many).

Just after re-purposing these speakers into an apartment loft here in January 2018, I noticed that one of the couplers was making a blubbering sound. I could stop it by very gently placing my finger on the surround at about "5:00-5:30". I believed I was securing a cut/tear in the surround by the sound and the way it was behaving.

Turned the speaker upside down, removed the plate, dropped the sock, and was shocked to find the surround looked perfect/brand-new. Poking at the "puck", definitely showed interference in between the voice-coil/magnet. I noticed that the spider was deformed and having no driver experience, novicely assumed it appeared gravity and time had won. The spider was pushed in at 12:00, and pushing out at 6:00. I slipped a blade through the basket, and applied gentle pressure to between the base of the cone and the spider lifting it towards 12:00, and the would cure the interference. This could also be done by gently tugging on the leads into the cone.

Imagining all the ways to try to tweak the spider and/or surround to make the assumed re-centering repair, I wet the end of a Q-Tip and pained the edge of the spider to see if the spider was water absorbent, and it was. So, figuring I had nothing to lose, in worst case it was going to Vandersteen for refurb anyway, I decided to "paint" the entire spider with water using a Q-Tip. When it was damp (not WET), I reached my finger through the cage and gently massaged the spider.

The spider now looked reasonably flat, but even more interestingly, the voice coil was now centering further into the magnet, as though the deformed spider was also forcing the voice coil un-naturally out. I wrapped a paper towel onto a ball-point pen, slipped it into the cage inside the leads to keep tension/"pre-load" on the spider while it dried. (testing/poking at it to confirm it was in position to eliminate the interference).

After a few hours of drying, the pen/paper towel ("pre-load") was removed, interference was GONE, and the speaker now plays perfectly.

I only took two pictures as I was doing this (1 being the original deformed spider, and 2 with the damp (now relaxed) spider with the pen/paper towel ("pre-load") tugging on the leads). I will add those pictures here as soon as I can figure out how to do that.

http://i1126.photobucket.com/albums/l611/kmckenn2/A__70CF_zps1ycecugm.jpg

http://i1126.photobucket.com/albums/l611/kmckenn2/A__F8C4_zpsggdhx2eu.jpg

kmckenn
I can't see what you were doing from the pics, but in any case, you are a brave man. 
Congrats!
B
I worked on my Vandersteen 5A's.....I proceeded with great caution - took me many days.....but removed the tweeter, midrange, crossover, bass amp, et al.......sent them to Vandersteen to find a bug and while it was there to change all the batteries.  Speakers are working fine now....but a brutal project.  I look back with a smile, but......
Hi gndrbob,

The first picture is a close up of the "spider" (the tan piece) through the basket, with the leads going into the cone up, or at "12:00". What is to be seen here is basically a "before shot". Look at the concentric ribs, and how they are not shaped the same all the way around, they appear pressed in near the top, and bulging out at the top. Another thing to look at is look at the relationship of where the shiny black cement ring is at the base of the cone and how far in or OUT it is compared to the outter edge of the spider where it is cemented to the basket.

The second picture is after the spider had been dampened with water (using a Q-Tip as a "brush"). The leads are on the far side of the cone to the left. You can see the blue ball point pen with the paper towel wrapped around it, and the leads going into the cone wrapped over the paper towel to GENTLY pull the voice coil that direction while the driver was drying in the sun on a window sill. And again, the other thing to look at is now that the spider had been dampened, it is now much more symmetrical, consistent shape around the entire spider, AND how much further into the magnet the entire cone is now resting. It’s as though the spider was acting as a spring with tension, and un-naturally holding the cone/voice coil further out of the basket/magnet.

Had I known this would work as well as it did, I would have taken more pictures to document what I did in more detail, as it was, I was just texting a fellow Vandersteen 2C owner and friend what I was getting into. It’s the only pictures I took.

Here is the basic components and operation of a driver.
https://www.youtube.com/watch?v=XMTjFxpRADI


Glad it worked for you
adding water to Vandersteen’s will be the last thing I think of.....