An singular loudspeaker on the side of the road was enough to make me turn the car around, retrieve the treasure, and leave behind just the plywood "free" sign as I drove away with fixer-upper of vintage speaker. Three feet tall, and sporting four woofers, a port, and some mystery crossover/loudness adjustment, this worn warrior was a few easy and inexpensive steps away from re-living its glory days:
1) Un-denting the dust caps
2) Re-foaming the woofer
3) Repairing paper cones
In order to complete these steps we need the following materials:
-sewing needle or safety pin
-speaker re-foam kit that fits the woofer in question (I got mine from SpeakerWorks.com http://www.speakerworks.com/foam_surround_sizing_s/63.htm)
-source of cotton fibers (cotton swabs, cotton balls, yarn, or whatever you have)
Step 1: Un-denting the Dust Caps
The dust cap in the center of the speaker protect the voice coil and motor that drive the speaker, so when a toddler pokes in a dust cap like it was bubble wrap, keep in mind the dust cap is just doing its job and keeping the crucial (and more expensive) parts underneath safe. It is also much easier to un-pop a dust cap than replace a motor structure.
This is where the sewing needle or safety pin comes in handy. Poke the tip of the needle or pin into the dent in the cone, and position the needle sideways so as to allow one to pry/pull the dent out. Using the needle/pin to get inside the cap, one can push out smaller dents and wrinkles.
Alternatively, a vacuum cleaner hose can be carefully placed over the cone, and the vacuum may pull the dents out. This works for larger dust caps.
The dust cap won't look like new, there may still be creases in it and a small pin hole or two, but it will be in much better shape than it was.