Replacing "damaged" speakers in Williams diesels

Are you certain that the speakers are damaged?  From your photograph it looks as though the glue is only on the rim of the speaker, and not on the moving part of the cone.

I do agree that it's not good practice to glue speakers in this way with over generous blobs of glue. 

The Hot Glue has been applied to an outer portion of the speaker cone so that removal would rip the edge of the cone. All 4 of my engines have the same exact defect. I have purchased replacement speakers of better quality.

Of course, you do realize that you can hit that hot glue with a heat gun and remove it, right?

Better speakers are available as replacements. I will just replace all of them. My main intent was to inform readers that their Williams products might need to be inspected for the hot glue problem.

I now have some miniature speakers that will easily fit in the 44-ton body.

I don't doubt better speakers are available, but I'm not sure that slimline one you picture would be classified as "better".   I presume you're going to put a baffle on it, right?

Precise sound quality is not needed for a electronic horn. It is just a electronic tone that doesn't require a real hi-fidelity speaker.

The baffle was for volume, that little speaker with no baffle may be pretty low in volume.