How can I fix this old E145?

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04-09-2022, 04:06 PM
laixl

How can I fix this old E145?

I received an E145 woofer off craigslist. It looks in great condition, but the voice coil won't move easily when I push the dust cap. It seems the woofer was buried in sand for some time, there are many fine magnetic sands got inside the rear port of the magnet. I believe the sands block the movement of the voice coil.

What the best way to clean up the inside of the magnet? Do I have to recone it? the original cone looks in excellent condition.
04-09-2022, 04:34 PM
gasfan

Quote:

Originally Posted by laixl

I received an E145 woofer off craigslist. It looks in great condition, but the voice coil won't move easily when I push the dust cap. It seems the woofer was buried in sand for some time, there are many fine magnetic sands got inside the rear port of the magnet. I believe the sands block the movement of the voice coil.

What the best way to clean up the inside of the magnet? Do I have to recone it? the original cone looks in excellent condition.

Sounds like the dust filter disintegrated, and got into the gap. That would cause that obstructed movement. You'll have to remove the cone and clean out the vc gap. Better to remove it as a unit. With some ingenuity you won't have to remove the dust cap in order to shim it during re install. MEK is the product to remove the spider and surround. Sparingly brush on a thin layer and wait 5-10 min. You may have to repeat as required(better to not overdo). Gently pull off the surround and spider making sure you don't pull off the tinsels. They can be unscrewed with the posts once you turn the freed cone out of the way. The MEK will simply evaporate in about a 24hr period to be safe. "Safe" is the operative with MEK as it's deadly. Make sure you either do it outside or with serious ventilation. You can re shim with narrow strips of ?/paper, plastic, whatever suitable thickness(strips of paper about 3/8" wide in 5 positions in the gap long enough to grab and pull them out multiplied equally to fill the gap, not tightly, just a bit firmly)and spot glue the spider between the strips to re center the vc to re install, then pull the strips out and glue down the remainder of the spider, then surround. Gently does it. Done!

simple.:)
04-09-2022, 04:43 PM
laixl

Thanks you very much! On my way to HomeDepot to get a bottle of MEK:).

Quote:

Originally Posted by gasfan

Sounds like the dust filter disintegrated, and got into the gap. That would cause that obstructed movement. You'll have to remove the cone and clean out the vc gap. Better to remove it as a unit. With some ingenuity you won't have to remove the dust cap in order to shim it during re install. MEK is the product to remove the spider and surround. Sparingly brush on a thin layer and wait 5-10 min. You may have to repeat as required(better to not overdo). Gently pull off the surround and spider making sure you don't pull off the tinsels. They can be unscrewed once you turn the freed cone out of the way. The MEK will simply evaporate in about a 24hr period to be safe. "Safe" is the operative with MEK as it's deadly. Make sure you either do it outside or with serious ventilation. You can re shim with narrow strips and spot glue the spider to re center the vc for re install, then pull them out and glue down the remainder of the spider, then surround. Gently does it. Done!

simple.:)
04-10-2022, 03:53 AM
edgewound

Quote:

Originally Posted by laixl

Thanks you very much! On my way to HomeDepot to get a bottle of MEK:).

You won't find MEK at Home Depot in California. Sale was banned in California a few years ago. Acetone is your only hope...unless you wanna drive to Nevada or Arizona for MEK.

And...the spider is probably bonded to the spider landing with cyanoacrylate. The solvent for cyanoacrylate debonding is nitromethane...and it doesn't work very well, either. You might be able to debond the surround with acetone and lots of patience...unless it was also bonded with cyanoacrylate. Late 1980s into the 90s it was built this way. If it was reconed outside the factory with a factory kit and rubber based glue, disassembly is more possible

If what I think above proves true, the best way to go about cleaning out the rotted foam between the top plate and voice coil former is to cut off the dome around the glue line with a fresh exacto blade, clean out the goo, and reglue or replace the dome.

Best of luck!