Magnavox speakers blown

yes buy a sound bar to replace

Unfortunately, it sounds like the speakers are blown out. All you can do is replace the whole speaker.
How to Tell If Your Car Speakers Are Blown

Something's crossed, keep power lines and sound lines seporated double check wires in and out u could have bad sound wires and if so of home just buy new for a car get the RCA lines with a built in ground.

magnavox model 1p3760 is a stylus for a phono.

Regardless, if the woofers are working they will vibrate. You can feel the cones moving. Damaged surrounds won't kill them.

As far as repairing or replacing them, you need to define the speakers better.

Product Description 37" HDTV, LCD Widesreen, 1366 x 768 resolution, 720P, Integreated ATSC tuner, HDMI, 2 HD component and 2 S-VHS inputs, 3D combi filter, Delivers Crisp Sharp High Definition picture quality, built in speakers for high quality audio sound. ES DE 720P

If you cant buy one from Alpine (usually costs half the cost of head) then you might be out of luck. For the price of faceplate, youre half into a whole new unit just about!

I have experience with that model of speakers. When they give up the ghost, the volume is VERY low. But just to be on the safe side, check the volume properties to make sure nothing is set too low. Start>Control Panel>Sounds and Audio Devices. Check the slider bars here, check in the Advanced area as well to make sure nothing is low and check the Speaker Volume as well. If all the bars are set to their maximum, it's time for some new speakers.
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there is actually a fuse in the subwoofer

I have a set of these speakers.