In alt.home.repair, on Mon, 04 Dec 2017 09:19:06 -0500,
wrote:

On Mon, 4 Dec 2017 13:14:31 +0000 (UTC), harry newton
wrote:

I haven't worked on speakers in decades.
http://wetakepic.com/images/2017/12/04/speakers1.jpg

How do we debug a scratchy sound?
We can isolate it with the balance to a single speaker.
But is it the speaker? Or something else?
If it's the speaker, where is a good place (other than the dealer) to get
speakers to fit a car rear deck? Are they all standard sizes nowadays? Or
is each unique?
I'm helping the neighbor's kid refurbish a beat-up 2005 Camry where I
helped her kid put in new speaker covers this weekend but the scratch sound
persisted (we thought it might have been the crud or vibration from the
crumbling melted-in covers).
The scratchy sound persisted even with the newly replaced covers.
http://wetakepic.com/images/2017/12/04/speakers2.jpg
Any suggestion on how to debug the cause of the scratchiness?
If it's the speakers themselves, are these things standard sizes nowadays?


Interchange the wires at the speakers - you'll prove that it's the
speaker and not the stereo or wiring.

You mean change + to - at each speaker? If that's what you mean, not
only will that take a long time but it won't prove anything.

And by the way, OP, you have to observe polarity when you install new
speakers or reinstall old ones, or the sound will be terrible. There
is usually a red dot on the Plus connector of the speaker. I'm sure
there are better instructions with any new speaker you buy, and old
speakers should be reinstalled as they were.

Pull out the bad speaker & look for a tiny tear - try fixing it -

That's a good idea. I take scratchiness to refer to something other
than a tear, but tears exist too. Buzzing or humming, and maybe
scratching on occasion (because who knows what sound that really refers
to) is caused by a tear in the cone.

http://www.300guitars.com/300s-tips/...speaker-cones/

He is vague when he says, Elmers the same as we used in grade school.
Elmers white glue comes in two kinds now, "School" glue and the
original. I assume that since I'm not 7 years old anymore, any
advantage the school glue has** is lost on me and the other one is
better.

**It's washable, even after it dries, I guess.

But for rips I wouldn't use white glue like he says. I've used rubber
cement several times in the past with good results. Rubber cement is
flexible.

This bit about a patch might be a good idea for major damage but most
little rips just need a few drops of rubber cement.

or shop for a replacement.
John T.