Sounds like I blew a speaker. I turn the volume up too high, and one of the rear speakers gives that awful blown speaker sound. But, the speaker cones aren't torn anywhere.

The next day, the blown speaker noise stopped. Last week, it came back and a rode a couple miles with me, then vanished. Now, everything sounds fine again.

Wiring looks the same as always, and not corroded. The other three speakers aren't having problems. I'm confused. Is my speaker dead, alive, or Schrödinger'* cat?

Maybe

A blown speaker wont have a torn cone... when a speaker "blows" the voicecoil is damaged. Its not a problem u can really see

One thing you can do to test it is lightly push the cone in and listen for a rubbing or grinding. Depending on how badly and how a voice coil burnt, you can usually hear it crackle and grind as you evenly move the cone in and out. A good speaker should move in and out with no sound as long as you are pushing evenly.

True...also pull the speaker out and smell the pole vent, if blown, will smell burnt.

We aren't talking rocket science here. For any speaker, including subs. Check the ohm-age. No reading means a burn in the voice coil. Full reading means melt/short. If the speaker ohm-age changes with you pushing gently in on the speaker cone and it returns to it norm position, it good.

Damn, look at John dropping some knowledge!

woot woot you tell em john lol

you know.... as much as i've played with audio components, not once have i ever thought of doing this....