Anyway to check speakers?

[AKcharger]

I tried out my AM/FM radio today and it worked for a bit and stopped, still got power (could see the little FM light) so I figured I'll put the ol' AM radio back in...well now that doesn't work. Only thing I can think of is the speaker, the AM/FM is the one with the cassete tape adapter so it's supposed to be powerful. Any way to test speaker?

Thanks

[Plumcrazy]

An ohm meter should give you a very low resistance reading.

[Nacho-RT74]

you can do it with just a 9 volts batt, just small contact between speaker terminals... you will see how cone moves and will heard a TUN.

Of course, also ohmeter ( multitester )... it should be around 4 Ohms I think... all car audio spekares impedance is around that.

[AKcharger]

So If I connect the 9 voly to the speaker I'll hear static?

[Nacho-RT74]

No, just will see how cone will go in or out, depends of what polarity you plug on speaker terminals, and will heard a hit like a TUN, or TIN, or CLUNK, or PIM hehehe because will se just one move on cone.

Sound is a senoidal wave with positive and negative polarity, like altermating current that makes the cone moves in and out with magnetic field inside the speaker coil and that makes sound with vibrations... with a 9 volts batt you are sending just one polarity of a wave, like a square wave on just one way, and cone will stay in or out for a while you'll keep batt plugged. will be just one out of balance of magnetic field on coil.

Of course, just make the contact for a second and release, don't keep it plugged. Once you unplugg the batt cone will come back to its original position.

[AKcharger]

Copy!

[phat69charger]

Here's some more info: http://www.carstereo.com/help/Articles.cfm?id=60 or http://www.crutchfield.com/S-PJD5RAtpO6a/tech/kb478.html

[AKcharger]

OK I couldn't see the speaker move but I ddn't hear anything, no hiss no nothing. Used a 9 volt batt

[Nacho-RT74]

ok, then apparently is damaged...

If you want to re-check, just make several continues contacts to try to heard the hits everytime you conect must be a hit. Similar to knock a door.

speaker is a cheap stuff to rebuild if you want to keep the stock one.

[AKcharger]

no resistance, pulled speaker and it was trashed! I slaved in a little surround sound speaker and radio checks out..thanks guys!