I recently installed a 68 am/fm delco from a cutlass in my car and wanted to hook up 2 speakers under the front buckets. I'm getting conflicting information on the correct speakers to install... some say 8 OHM and some say 10 OHM.
Which is correct? Thanks!

 

Should be 10 ohm, 8 ohm will work as long as your cranking the volume way up as it will damage the output transistors.

 

On Delco radios of that vintage, the output transistor circuit is tuned for 8-Ohm speakers. If you use 10-Ohm, you will need to retune (rebias) the output transistor collector. If you don't, you will have poor output but there will be no radio damage.

There have been a lot of new speakers sold where the resistance does not measure what they claim. Check your speaker coil with the speaker disconnected from the radio. The speaker coil must measure 1.5 Ohms. If it is 1.3 Ohms or less, it will overheat the output transistor stage and could draw so much amperage that the 12 Volt supply wire to the radio could be damaged.

 

Everything i have read about replacement speakers say 10 ohm.

 

Thanks!