Damaged Woofer?

[kininigin]

I was listening to some music (electronic) and noticed when the kick drums came in,there was a vibrating sound coming from my right speaker.

So i swapped the left and right cables around,still the same sound.I found a site with some test tones on it and did a bass frequency sweep.

There is definitely a 'soft' vibrating sound from 72Hz down to 32Hz :(

What could/is causing this? Will this mean a new Bass/mid driver?

[Firebottle]

I have come across speakers that have been thrashed and the voice coil or part of it has come loose.
Overload has caused the glue to fail. It is more audible at low volumes when the music signal isn't masking the vibrating loose coil.

If you can hear it at low volume it's likely that is the problem.

Alan

[kininigin]

I have come across speakers that have been thrashed and the voice coil or part of it has come loose.
Overload has caused the glue to fail. It is more audible at low volumes when the music signal isn't masking the vibrating loose coil.

If you can hear it at low volume it's likely that is the problem.

Alan

I can hear it at low and high volumes.When at low volumes though,it's the lower freq's that make it more obvious.

[Firebottle]

Sounds unlikely to be a loose coil, they vibrate well at mid frequencies.

You'll have to inspect the driver visually, maybe the flexible wire(s) onto the back of the cone?

[Reid Malenfant]

Try rotating the driver through 180 degrees ;)

The rear spider often starts sagging under the weight of the cone & voicecoil after many years use, by rotating it it'll encourage it to centre again. It's quite possible that the voice coil is rubbing on the motor assembly.

It often works :eyebrows:

[kininigin]

I'm a little dubious about inspecting the driver! Being active,will there be issues with the way the amps are connected?

When i took the back panal off last time,i remember that there wasn't much give with any of the cables!

I also had to get the soldering iron out,due to my cackhandedness :doh:

I'll have a little think first,before trying anything.

[Ali Tait]

Could be as simple as the driver fixing screws/bolts needing tightening.

[walpurgis]

I think Mark's right, sagging suspension due to age is a common cause of voicecoil misalignment and hence buzzing or grating noises. Try the rotation thing.

Just a thought, it could just be a bit of speaker wadding touching the back of the cone, its not unheard of. Worth a look.

Taking the unit apart should not be hard, take a few photos as you go so you have some reference when re-assembling.

[kininigin]

Ok,i'll have a go at turning the driver and the other suggestions.

I hope it is something simple!!

Well i just turned the driver around,there was a bit of wadding stuck to the magnet,but that was it.Didn't appear to be anything sagging.

I think i've found the problem though.The dust cap is starting to peel away.I didn't see this at first as the driver was the other way up!!

Is this an easy d.i.y. fix? It's a soft dome type.

[walpurgis]

To re-secure the dustcap, just use a small paintbrush to run a bit of adhesive around the inside of the opened joint. I'd suggest using 'Aleene's Original Tacky Glue', as it is water based and easy to wipe off any surplus. You may need to apply a bit of light pressure now and then as it hardens. I buy mine off eBay, it's good stuff for many speaker repair jobs.

[kininigin]

Cheers Geoff,would a general multi purpose glue be ok?

I'm leaving sunday anyway,so if not it will have to wait till next year!!

[walpurgis]

A good contact adhesive would probably do the job, but water soluble is easier to use with a brush and easier to clean off if you make a mistake.

[kininigin]

Ok,so not a good idea to use multi purpose glue?

[walpurgis]

Best do it as right as you can I reckon.

Some "muti purpose" adhesives would not be a good idea.

Aleene's Original Tacky Glue is only a couple of quid on eBay.

[kininigin]

Well i'm back in the uk now and have ordered some glue,so hopefully i can fix the dust cap without any issues!

[kininigin]

Cheers for the tip Geoff,the glue worked a treat.I now have smooth sounding bass :D