Broken speaker?

[dangee]

I’m currently running an EBS TD 650 through two EBS neo 112’s. There seems to be an issue with one of the two speakers. Basically, it’s amplifying the bass but with the addition of a noise that is somewhere between low level distortion and rattling. It is far more noticeable at certain frequencies (for example playing an Eb) than others.

I have used the same speaker cable to both cabs, so can rule that out. When I play through the other cab it is crystal clear.

Any ideas?

Thanks,

Dan

Edited March 14, 2010 by dangee

[Mr. Foxen]

Loose stuff rattling inside it? Such as the lining coming loose, or a wire touching the cone.

[lemmywinks]

Could be the baffle board or a panel coming loose, try getting someone to play through it (on the offending notes) and push different sided of the cab.

This happened to me on my old Hartke cab, the rear panel was vibrating against a vertical panel of wood. Screwed it down and it was fine.

[Alien]

Also, check all the cab hardware such as grilles, jackplates, handles etc. to see if they're loose and rattling, tighten if needed. Leaks around handles, speakers etc. can be a cause of distortion.

A

[Phil Starr]

Check the bolts that hold the speaker down also. If none of this works the speaker may be coming unglued, check the corrugated surround and the dust cover (dome in the middle) They can be re-stuck with a latex based glue (Copydex) and small holes patched with layers of tissue laminated in copydex. Unless it is still under guarantee of course.

[dave_bass5]

When i got my 1212L i had a sort of low level rasping/distortion sound coming from the cab. It took me ages to track it down.
It turned out it was a very small section of the dust cap that had come away from the cone. You couldn't see it without pressing down on the cone.
Very annoying as it got worse over a few gigs. At first it was hardly noticeable but after a few gigs it was quite loud.

Edited March 10, 2010 by dave_bass5

[dangee]

Right...

I've removed the grille and both handles, taken the speaker out and checked it over (looks fine) and put it back, tightening the screws. I've checked that no wires are touchng the cone, taken the jack plate off, checked it out and reattached it.

It's quite difficult to access the internals as you can only really get inside through the holes where the handles are (there is no removable back panel). It's also difficult to see much as there is some sort of white padding against the wooden sides.

The bizarre bit is that it still responds to certain frequencies (now a C instead of an Eb) and if you put the cab on its side it seems to stop, while if you sit it flat you get the noise.

Any further ideas...other than keeping it on its side?!

[Mr. Foxen]

Gotta be loose stuff then. Unless it is the speaker, in which case, unbolt the speaker and rotate it, bolt is back so its on its side.

[JTUK]

hhmm.. odd.

What does the speaker sound like outside the cab... ? you will not be able to run this very loud of course, or rather, you shouldn't...but just as a test of one speaker against the other. Or load the 'damaged' speaker in the other cab..?

You need to isolate whether it is the speaker or cab first..

You can have a damaged speaker which looks and feels fine ...but I would expect it to distort at most low freqs..as soon as the speaker gets a low load..