Educate me on Speakers!

King Fan

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I gotta say it actually sounds better than I thought it *might.* Tiny motor, 70-year-old paper. But as I say, you're hearing it better in person. If volume and 'weak' are hard to evaluate in the room, they're way harder in a recording, so use your ears, not mine.

Voice coil rub may be audible or palpable when you gently flex the cone with your fingers -- but I'm not sure that's true in all cases. I've seen some good YouTubes about re-centering / re-rounding the voice coil -- sorry, didn't bookmark 'em. But I do like this text tutorial by Ted Weber, if it fits your scenario. (Some folks cut strips of old film instead of card stock. And I've had some luck using 99% isopropyl instead of acetone.)

"...take a 3×5 index card and cut it into a strip that is the correct length so that you can form it into a circle and stick it down into the gap between the inside of the voice coil and the outside of the pole. This will help form the voice coil back into a circle. Next, lay the speaker back down on its back. Take a Q-tip or small paint brush and dip it into a bottle of acetone (finger nail polish remover). Spread a small amount of this acetone on a couple of the rings of the spider, which is the brownish/yellow corrugated disk attached to the backside of the cone at the base of the basket. Next, place a jar lid or other disk on the cone where the dustcap was and let the speaker set overnight. The lid or disk will prevent dust from getting into the gap overnight, and the acetone causes the spider to relax and reposition slightly, thus repositioning the voice coil. The next day, remove the lid and the index card strip and see if you still have a rub. If you do, try the acetone again, same procedure."
 

printer2

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Would that also account for the lack of volume Printer2?
It could be my imagination but it seems to get a bit louder as time goes on.
Perceived loudness is such a hard thing to be subjective about
Guessing without hearing it but I would think the cone is stuck. Scratchy treble the only thing getting out as it does not need much movement.

The video would not load for me before, listening to it, it sounds better than I expected. If anything you could buy a new voice coil kit and rebuild it.
 

Swirling Snow

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I heard "Rumble" the first time. :)
The second sounds like Hendrix playing softly, IF he had a really light weight speaker that followed all the delicacy of his playing. No promises, but I don't think you have cone rub.

Still, that's just lacquer insulating those wires and it will rub off fast, causing the coil to short out, so King Fan's advice to follow the Weber procedure is worth the trouble, I believe.

Probably too late to says this, but do not push the cone in to see if it's rubbing. If you don't press perfectly, you'll cause cone rub.

The lack of bass is mostly due to a very weak magnet and a small diaphragm with limited motion. I wonder if you could steam the edge of the cone and reposition it? Weber might know.

Not that I notice the lack of bass, I played through a 6" speaker for about 15 years. I think your speaker sounds wonderful. I can't wait for my Celestion Blue to sound that pulpy. :)
 

Swirling Snow

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I've tried to save old old speakers, decided it isn't worth it, and it's no fun to throw them in the dumpster either. If ya just like to tinker, have at it.. but there are fantastic new speakers to be had.
Generally, I agree. Speakers have benefitted a lot from aerospace, whereas our poor tubes amps have not. And I'd never gig with a vintage speaker.

But for recording jazz or blues, a speaker like this can be a delight.
 

printer2

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Don't do anything to the surround, the spider can be adjusted somewhat before the nuts are tightened. The speakers were also designed to be semi-enclosed. Enough space behind them and some perforations in the wallboard back. Not sure how well they would do in an open back cabinet. The pair I had was in a sealed enclosure.
 

Bitsleftover

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Thanks to all of you for all the excellent advice.
I should get some time to do more tinkering later.
I removed it from the cab yesterday, and it is definitely rubbing now, although i would have put money on it being ok when i reassembled previously, so either something has shifted or Im always open to the suggestion that I may have been wrong.
Out of interest I emailed Celestion to see if they had any info on it. They emailed straight back asking for photos as they have no record of a “ModelP10R” so it will be interesting to hear what they make of it.
I would like to get this working properly just for the sake of it really. Im sure it will suit some sort of small amp even if neither of the two I have at the moment. Could be an excuse for another build?
I only ever play at really low volumes in the living room these days so it will never take any abuse.
Ill try adjusting everything on the screws then follow the Webber advice if that doesn’t do it. Excellent info KF
Thanks again.
Ill keep you posted.
 
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Bitsleftover

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I tried adjusting on the screws but couldn’t make fine enough adjustments while fighting the magnetic pull.
I’ve carefully removed the dust cap to see what’s going on and still couldn’t move the coil properly so removed the magnet again to see what’s going on and found the edge crumbling away
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