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[Nid]

Hi! This is a quick one. So, there is a Trace Elliot 4x12" cab driven by an Ampeg head. A bass guitar rig used mostly in studio rehearsals. It's about a month or more now that one of the woofers produces distortion. You know, that kind of crackle like a square wave has been fed to it. It is tricky because at first you think it is just a usual cabinet's groan caused by a loose screw or something. By my xp, there is some anomaly with the coil not moving properly inside the magnet, am I right? We turned and placed the driver 180degrees so that the magnet "is hanging" the opposite as it did all these years. The phenomenon diminished a little but after a few days grew bigger. Now we are pretty sure that the woofer is slowly dying. I am asking for people with greater xp in speakers to tell:
1) what can lead to this problem?
2) is there a way to fix it before the woofer dies?
3) is it a threat for the amp? (using that speaker)

Thank you and best regards. Nid

[Fletcher]

I'd say it's probably time to buck up the $75- and get the driver reconed... but that's an idle supposition.

[Nid]

thanx! That means there is no way to cure the driver without reconing?

[Fletcher]

Not that I know of... but I've been wrong many [MANY!!] times before.

[Buzz]

Nid from my expirience thats the voice coil scraping along the guide/magnet , ITS DEAD replace or recone it , or remove it and the cab will become ported !!!!

( you might want to try this it makes a hugh difference in the sound of the cab maybe good maybe bad ?? )

LAter
BUzz

[Tidewater]

Yes, sounds like a coil problem: replace speaker.

Push in on the cone, evenly. Do you feel scraping?


M

[Nid]

Actually no, there isn't any obvious scraping when moving the cone. We took the dust cover off and there was visually no problem (as far as I am aware of). No contact between coil and magnet. Also, the coil looks neat, not darkened by overheating. Still the speaker makes distortion with any source fed to it (bass guitar, LF test tones, music) and we tested with another amp too. So we are after reconing or replacement. But I fear that we won't find a new one. It's a Celestion C10T-80 (it reads "Custom made for Trace Elliot"). The cab is actually 4x10" and not 4x12" as I wrote in the first post. Any info will be helpful. Thanx! take care

[max cooper]

One of the first things I'd do if the state of the driver is still in question, is to put an Ohm meter across it.

A "blown" driver can show as either no resistance or infinite resistance.

If the driver shows up on the meter as somewhere close to it's resistance rating, then you can start checking other stuff.

[Nid]

Yes this is the first thing I did. Resistance looks fine. Tomorrow we'll get the speaker to an expert for reconing. Hope he does a good job and revive the driver without changing its sonic qualities too much. Any valueable info he may give, I will share it with you. Thanx to all.

[danickstr]

if you run into trouble with the reconing, you could try madisound.com (no affiliation w.me ) since they have a big list of speakers that are the best available replacements for many types of cabinets and this way you get a factory made speaker that should have more consistent tolerances, as well as better specs (although many purists will want my head for suggesting this approach).

ugh its a celestion...ok forget what i said if you want the true vintage blah blah but for other apps it is a valid approach.

[amorris]

recone obviously but if you are sure that it is not rubbing on any side even a little, you can look for torn or seperated components. if it is the speaker you will find it. take speaker out of cab and make it fail. can you touch the speaker when it is failing and make it go away mostly?