There are probably many reasons but a start would be to remove the speakers and check them for connections. If the vehicle is older there could be errosion depending on the speaker placement and the type of vehicle. You could also look at the connections at the rear of the head unit or a possible break in the speaker wire going to the speakers. There could also be a head unit (cd player, tape deck, etc) problem like a "burnt" channel or wire harness problem.usually start AT the speaker and work your way forward.
the rear speakers are located in the back doors. you have to remove the door panels to get at them.
on what car???
front dash tweeters- 3.25" door speakers- 6.5" rear deck speakers- 6x9"
ones that work
a loose conection
The dash speakers are 3 1/2, and the rear speakers are 5 x 7. If you need to get sizes for your car, go to crutchfield.com and click on outfit my car. It will tell you all the sizes for the speakers in your vehicle!
Although I think the Miata is a great car it wouldnt be practcal for me as my next car. The Miata s a small 2 seater convertibe that wouldnt work for a family.
The size of the stock rear speakers in a 1991 Chevy are 6"x9". You can go to crutchfield.com for any other car stereo needs, just provide the site with some information on your car's year, make, and model, and body. From there they will provide you with the correct speakers that will fit your car. I hope that has helped!
6x9
with rear seat audio: ; Front speakers : Front Door: 6-3/4" Rear speakers Rear Deck: 6x9" http://www.crutchfield.com/S-96jByR9lvTK/app/car/mycar.aspx
It varies depending on model year but most Ford Crown Victoria's have 5x7 / 6x8 speakers in the doors and 6x9 speakers in the rear deck. Station wagon models have 5x7 / 6x8 speakers in the rear cargo area. The links below have a lot of useful info on the subject for 1992 and up Crown Victoria models... Front speakers: http://www.autoclinix.com/Mercury/Front%20Speakers.html Rear speakers: http://www.autoclinix.com/Mercury/Rear%20Speakers.html Depends on the year of the car, and which speakers.
On my Pug 206 I had speaker terminations for rear speakers but no rear speakers fitted. I simply chocolate blocked each one to extend the speaker wires to the boot of the car. Even if you have rear speakers fitted it should still be possible. I've got a 3dr car, so it was fairly easy. If you have a 5dr you may have to try and remove fittiings to run the wires properly