MG Car Repair: British Motor Corporation radio, 4 ohm speakers, central arm

Question
Hi Barrie,

I recently found an old BMC 12 volt negative ground AM radio.  Presuming I can get it to work, I would like to put it in my 1968 MGB (my vain thought is that it is what was in the car originally...).  If this is correct (or at least close) how many speakers did the factory put in the 1968 MGB?  And, to be more greedy, might you know the ohm rating of the speaker(s)?  I don't have speakers, yet.

Thank you in advance for any and all information.

Regards,
Dan


Answer
Hi Dan.  Does your car have the early centre console without an arm rest?  If so, your car was intended to have a single 8-ohm speaker in the centre of the console.  

If you have a central arm rest, then you should have two 4-ohm speakers, one in each door.  If you take the door trim panel off, you should find that it is made from hardboard, and there will be a circle of perforations down low at the front, which you can cut out with a sharp hobby knife.  If you decide to fit door speakers, buy the shallowest ones you can find, or else they will stop the window glass from winding down cleanly.

As regards the radio, how many speaker wires does it have?  If there are 2 wires, or a socket for 2 wires, then it will be an early set that runs a single 8-ohm speaker.  If it has 3 wires, then it supports two 4-ohm speakers and the middle wire is common to both speakers.  If it has 4 wires, then you must fit 2 speakers.

You can wire 2 speakers in series, so a pair of 4-ohm speakers can be wired across an 8-ohm radio.  If you have the early setup, I would cheat and mount two small oval 4-ohm speakers behind the centre console.