vintageHIWATTconvention.com

There are a lot of old Speakers out there with Voice Coil rub. I recently recieved a cab that really took a beating during shipping. As a result one of cast frame Fanes developed a VC rub.

I contacted several speaker repair companies and all of them but one said my only option was to send it in for a recone. Ted Weber had one technique to try. I loosely followed Ted's directions and took it quite a bit further. After fixing it, I wished I had taken pics of the process.

Thanks to Old School Dave, I have a couple of 40 watt Sound City cast frame Fanes to try and "Doctor-up". The main difference between these SC Fanes and HIWATT Fanes is the Dust Cap. The SC's had an Aluminum DC, unlike the cloth DC in the HIWATT Fane.

The DC has carefully been removed. With a HIWATT Fane, use a scalpal or razor blade to CAREFULLY cut out the center of the Dust Cap approx. 3mm from the edge. Leaving this lip is important for two reasons: it gives an excellent area to glue the replacement to and you avoid the delicate wires that attach to the cone.



Next loosen the four bolts that secure the magnet to the frame. Leave them barely threaded, but the magnet should have a small amount of play.



Sometimes you may have to remove the magnet completely and clean the cylinder where the Voice Coil lives.

Once the magnet is loose and there is no debris between the VC and the Inner and Outer walls of the Magnet, place card paper shims between the VC and inner wall of magnet.



Place shims in such a fashion that a uniform gap is created between the VC and inner wall of the magnet. 4 or 5 will be enough as the tolerances are tight and it will be difficult to place more than four.





At this point tighten the magnet bolts each just a little at a time until all are finger snug. Then using a wrench tighten each bolt 1/4 turn before moving to the next. Keep tightening each bolt 1/4 turn until all are tight.

Using plain finger polish remover and a cotton swab, wet one or two ribs of the spider. This is a solvent that will allow the spider to set in the new position.



Let sit over night. Place something clean over the VC to keep debris out.

to be continued...

Oh! My babies! I can't bear to look. Tell me they'll be o.k., Dr. Fane .

Dave

I just lucked into 6088..SE4123..100 watt.. 4x stamped 122231.. And when I say clean..I mean the baskets are shiny, not a snag in the tolex,S/P grill (tiny snag), the skids dont even have a scar of wear on the bottom.
But..the lower right speaker had a hell of a rub.

Followed this info to a "T", She's as tight and new as when it rolled out on '74.

This is the trick if anyone has a rubby speaker....saved my ass!!!
Did I say this was dead mint? I'd post pictures, but you guys arent into amp porn are you??
Pics when I get her back together!!
Cheers!!
Chris

Congrats on the score, Chris. Sounds like a rare find indeed.

Thanks for verifying the rub fix works and please do post pics when you can.

Dave

For a project at the university, I deconstructed an old blown Celestion G12-50 or something. Very cool to see how electricity is transferred into movement which creates sound.

Continued:
after sitting over night.
carefully remove the shims/spacers.
Press down on the cone to test for a VC rub.

If the cone moves freely without rubbing, glue new dustcap in place, let sit over night then load your speaker.

If there is still a rub............go back to the begining and repeat the treatment. IF after three treatments the rub is still present, the coil is warped and a recone is needed.

When performing this does it matter what "new" dust cap you use?

stajerska wrote:When performing this does it matter what "new" dust cap you use?

Some. But, this would be a great opportunity to customize the sound.

I'm not a huge fan of aluminum dust covers on anything but Altecs and JBLs. I'd tend to go with a "British Cloth dome" on vintage Fanes.

Dave

I'd like to keep it "stock". So basically any cloth DC will work as long as it fits?

iirc, you want a 3" H dome.
if shopping from Weber.

Can anyone please tell me where I could get a suitable dustcap in Europe? Thanks!

This may sound like a stupid question but... what is voice coil rub and how can i see if my speakers exhibit it?

metamatic wrote:This may sound like a stupid question but... what is voice coil rub and how can i see if my speakers exhibit it?

Set your amp for its cleanest output, then play a low E on your guitar. If you hear a fizzing sound as the note decays, it's probably voicecoil rub (unless it's one of those normally fizzy Celestions ).

In cases where the front of the speaker is accessible, spread your fingers evenly around the cone and gently press the cone inward. If you hear any scraping, that's voicecoil rub. Be sure you're pressing the cone in symmetrically, as it's possible to induce (false) voicecoil rub by pushing the cone off-center.

Dave

gently press the cone

Just to emphasize .... gently .... if there is a rub the instructions above are very good, but keep in mind that with OLD fanes, you might need a bit of elbow grease to get the four main bolts to come loose ... and perhaps a bit of heat (propane torch) ... I needed some torch on one of mine ... BUT, be very careful ... just take it a bit at a time ... bit of heat ... try it ... bit more heat ... try again

j

I had to search on an external hard drive to find the photos.
the old photo hosting site is no longer in service.