[MI2600]

Newbie question.

1. If an auto speaker is connected incorrectly (+ to -), will it:

a. Damage the radio
b. Damage the speaker.
c. Just not work.

2. Will two same sized, but different brand speakers (and maybe different ohms), cause a radio failure?

Having problems with the radio system in my '86 El Camino. Thanks.

[matt167]

diffrent ohms, yes. diffrent brand, no.. reverse polarity, they will work backwards but they will work

[Oldguy48]

A regular loudspeaker simply has a coil of wire connected to it's input terminals. The loudspeaker is not polarity sensitive, because the audio signal going to it is actually an alternating current. Reversing the connections only means that for a given signal the cone will push vs. pull. You can prove this to yourself by momentarily connecting a 1 1/2 volt battery to the loudspeaker, and watching the travel of the cone. It will move in one direction, and by reversing the battery, it will move in the opposite direction.
The most important thing is the impedance of the speaker. If you connect a loudspeaker that has a lower impedance than what the radio was designed for, the output section of your radio has more of a load to work against. If the impedance mismatch is too great, the radio will eventually fail, or at least run hotter than normal. Most speakers are rated for either 4 or 8 ohms. Match the loudspeaker impedance to the radio if you can. Generally, a higher impedance speaker than what the radio was designed for is no problem with a transistor output radio, although the volume level may be lower than normal. The brand of the loudspeaker is of no concern as long as the impedance is matched.

[MI2600]

Thanks for the input.

I've lost two radios thus far. The last one played well soon after installation (a day or so). Then, I noticed the right speaker (a cheapy Walmart) stopped responding. Soon after, both speakers stopped and the radio itself went dead, ie no lights, nothing.

The speakers are mismatched. The other is of unknown origin. Neither denote what their ohm rating is. I know the older cars had 8-10 ohm speakers. This is in an '86. I'd thought, perhaps falsely, that it would take a less ohm speaker.

Any ideas?

[Oldguy48]

If you can determine the correct output impedance of your radio, you might be able to find a suitable replacement loudspeaker at
www.parts-express.com They have quite a variety of audio stuff, and reasonable prices to boot. Good luck

[MI2600]

Is there a method to identify the "ohmage" of a radio from the serial#, stickers, etc?

[Joe G]

The odds are pretty good that a Delco radio from 1986 would require 8-10 ohm speakers. Sometimes the impedance requirement is stamped on the outside of the radio.

There are bound to be exceptions, but all of the Delco speakers I have seen, even as new as 1996, are 8-10 ohm.


Hope this helps...

[MI2600]

Thanks.

Good to know. One of the speakers is Chinese and who knows what it is!

[MI2600]

I looked all over the two back-up radios I have. There's nothing about ohms or impedance.