Refoamed Woofer now rumbling & static Crescendo 3007

[Tim 700]

Just picked these up: http://audiokarma.org/forums/index....infinity-crescendo-3007.771471/#post-10574113

Re foamed the one woofer that had disintegrated surrounds last night. Reinstalled now a low rumble with static.

Cone moves perfectly in and out. Still attached at top and bottom.

When I tap it, it's rattling, not a nice drum sound

I guess the voice coil is rubbing.

Don't you hate it when you fix one problem and create another?

Thanks

 

[totem]

You would feel it when moved if the coil was rubbing, perhaps there is crap lodged between the coil since you mention
rattling.

 

[Tim 700]

Yes, I feel it, removed the dust cap, don't think I can get to it, definite
rattle when tapped on one side of cone. Was going to try the acetone fix found here in post # 10 http://audiokarma.org/forums/index....b-is-speaker-ruined-or-canit-be-fixed.736367/

 

[mars_volta]

Did you use a test tone while gluing? Both woofers will need new foam if it hasnt been replaced.

 

[Tim 700]

Did you use a test tone while gluing? Both woofers will need new foam if it hasnt been replaced.

No, I don't know what the test tone is while gluing. Is that when you keep the speaker plugged in?
I only reformed one.

 

[mars_volta]

Use a 30 hz tone to keep it centered. I keep this on while the glue dries and I work my around the outside lip until its stuck well.

Also, with those img poly woofers the black glue is recommended.

 

[Manuel64]

From your picture and description of the problem, it definitely looks like your re-foam is not centered. Your voice coil is rubbing. you will need to take the foam out and start over with new foam.

You can either shim it while the glue dries, or use a 30hz test tone while applying the glue. If you don't have a dedicated low frequency test tone cd, you can just play some music at a low volume while you glue. Just make sure that your woofers move in and out while you glue. You want movement, but it needs to be gentle movement. After the glue is partially dry, but still pliable, I usually move the cone gently in and out with my hands, feeling for any rubbing. A centered voice coil will move easily in and out. It will feel right.

For IMG Drivers, I always prefer the test tone method, over shimming. I like the look of the inverted dust caps as they came originally. They never look as good when glued back on.

 

[Tim 700]

Thanks for the tips. I thought I really nailed the re-foam, about the 5th set of speakers Ive done, never had this problem.
The dust cap is toast

 

[leesonic]

When the dust caps are so easy to remove on these, why not shim them?

http://audiokarma.org/forums/index.php?threads/infinity-crescendo-cs-3007-restoration.599202/

 

[cemerson]

Removing them is the easy part, getting them back on and looking correct is the hard part. The ones that can do this have skills. I'd prefer the test tone so it looks the way it did when it came from the factory, or as close as possible. Plus I woul rather not expose the voice coil if at all possible, just so I don't have to deal with something getting in there and rubbing.

 

[Tim 700]

Finally got around to working on this.
Am using this test tone from YouTube:

Wanted to sort these out before I work on a pair of JBL's I garbage picked.

 

[7.62]

I have that on CD and I've used it on all my refoams, JBL, CV, and Infinity. Only one failure and on a Watkins woofer, it played fine for a few minutes then started rattling again. Voice coil was toast.

 

[orsen]

i have had rattles caused by non perfect glue jobs
the surround then vibrates against the cone
i have also seen spiders come unglued and cause a rattle

 

[Tim 700]

So I re glued with the 30 Hz YouTube playing the whole time and let dry for 24 hours and NO RATTLE!

No Rub, I had to replay the vid as it's only 1 minute long, but it kept the voice coil from rubbing.

Now I've got to re-foam the rest of the speakers since they are all way expired and ready to die.