I have the original AM radio in my 70 Cuda . And I want to wire two rear speakers to it. But the radio only has one green and one black wire going to the front speaker. The radio works great so I don't want to replace it.
Any way I can splice the speakers to the radio with burning up the radio? Also what wire is ground the black or the green?
A quick question. Are you going to install a fader switch for the speakers? The FSM I have for my 71 Challenger has the wiring for a standard radio w/o stereo with front and rear speakers.
Terry
Not sure if you would get the power outage you would need to run three speakers off of one feed :thinking:
If you do, run small magnet style speaker. :alan2cents:
Quote from: 71vert340 on April 27, 2020, 11:32:39 AM
A quick question. Are you going to install a fader switch for the speakers? The FSM I have for my 71 Challenger has the wiring for a standard radio w/o stereo with front and rear speakers.
Terry
No, I just would like to wire them up with out fader switch.
Quote from: JS29 on April 27, 2020, 12:13:11 PM
If you do, run small magnet style speaker. :alan2cents:
I already have the speakers , they are 4 ohms,75 watts max output, 52 hz-2hz ,89db/ w9 (1M).
Your original radio will run hot and eventually burn up if you run it at less than the 8 ohms it's designed for.
The original speakers were 8 ohm speakers.
Also, the original AM radio was 2 watts.
You're really not putting out enough power to push 3 speakers, so you should probably install an external amplifier.
I don't recommend what you're attempting to do, but if you really want to try and see what it sounds like, here's how to do it safely...
It sounds like you have an 8 ohm dash speaker, and two 4 ohm rear speakers.
Excellent diagram :twothumbsup:
For comparison, here's a couple ways NOT to do it.
If you only want to connect the two new speakers, here's your options.
These diagrams are for original radios, which are stable (won't burn up) at 8 ohms.
If anyone out there reading this has a reproduction radio, or an aftermarket radio, they're typically 4 ohm stable.
That's per channel. Most aftermarket radios have 4 pairs of speaker wires, so they can handle 4 ohms on each pair of speaker wires.
These old original radios have one pair of speaker wires, intended for one dash speaker.
If anyone is looking for replacement 8 ohm speakers to pair with their original radio, check out turnswitch.com
Quote from: cataclysm80 on April 27, 2020, 04:30:03 PM
If you only want to connect the two new speakers, here's your options.
I think I am going to do the two rear speakers only now. So the top wiring diagram with the 8 ohms should be good right?
What would happen. If they are all 8 ohms? Would it just cook the radio? No one really uses the radio in these cars anyways
How would you wire it using the 8 ohm dash speaker and a 4 ohm rear speaker
Thanks for your help!!!!
Wired up the two new speakers today and the AM radio . All works sweet!!
Quote from: gaddied on April 27, 2020, 05:38:41 PM
Quote from: cataclysm80 on April 27, 2020, 04:30:03 PM
If you only want to connect the two new speakers, here's your options.
I think I am going to do the two rear speakers only now. So the top wiring diagram with the 8 ohms should be good right?
Yes, that's the one to use.
Enjoy your tunes.
Quote from: 68bee on April 28, 2020, 11:40:55 AM
How would you wire it using the 8 ohm dash speaker and a 4 ohm rear speaker
For an 8 ohm dash speaker and a single 4 ohm rear, you'd want to wire them in series to have 12 ohms.
In series means that the wiring goes into one speaker, comes out of that speaker, and goes to the next speaker, look at the series diagrams above.
If you wire them in parallel, you'll have 2.6 ohms and will burn up the original radio.
In parallel means that the + on all speakers is connected to one wire, and the - on all speakers is connected to the other wire.
Ohms is resistance, so the more resistance you have, the quieter your speakers will be. With more resistance, you'll have to crank the volume knob more to get the same sound level, and you'll have a lower max volume. Lower max volume only matters if you're actually listening to the radio at max volume, otherwise you can just turn the volume knob up a little more and be fine.
With less resistance, you get louder speakers flowing more current, which can overheat things if you go too far.
radios / amplifiers are rated by what ohms they're stable at, and the old original radios were 8 ohms, modern or aftermarket are typically 4 ohms, higher end amplifiers can be 2 ohm stable. It just means that the quality of the materials used to build the amplifier can take the heat without failing.
Quote from: Shoooter on April 27, 2020, 10:15:30 PM
What would happen. If they are all 8 ohms? Would it just cook the radio? No one really uses the radio in these cars anyways
If you don't turn the radio on, then it won't matter which way you wire it. :)
What happens if all the speakers are 8 ohms depends on how many speakers it is.
1 8 ohm = 8 ohms
2 8 ohms in series = 16 ohms
2 8 ohms in parallel = 4 ohms
3 8 ohms in series = 24 ohms
3 8 ohms in parallel = 2.6 ohms
Once you hit 3 or more speakers though, you can start doing creative stuff like wiring some in parallel to lower the ohms and some in series to bring it back up.
2 8 ohms in parallel = 4 ohms + 1 8 ohm in series = 12 ohms
2 8 ohms in series = 16 ohms + 1 8 ohm in parallel = 5.3 ohms
4 8 ohms in series = 32 ohms
4 8 ohms in parallel = 2 ohms
3 8 ohms in parallel = 2.6 ohms + 1 8 ohm in series = 10.6 ohms
3 8 ohms in series = 24 ohms + 1 8 ohm in parallel = 6 ohms
2 8 ohms in parallel = 4 ohms + 2 8 ohm in series = 20 ohms
2 8 ohms in parallel = 4 ohms, wired in series with 2 other 8 ohms in parallel = 8 ohms (this is the same as wiring two 4 ohm speakers in series)
2 8 ohms in series = 16 ohms, wired in parallel with 2 other 8 ohms in series = 8 ohms (this is the same as wiring two 16 ohm speakers in parallel)
You want to choose the option that is the lowest ohms without going under whatever your radio is stable for.
Keep in mind that this info is for our old single channel radios with one pair of speaker wires.
The R11 option AM Musicmaster radio only put out 2 watts, so it isn't going to power a whole bunch of speakers. You might not get much volume.
Typical aftermarket radios are about 13 watts, have 4 channels (four pairs of speaker wires), and each is 4 ohm stable.
That's a better way to run four speakers that are 4 ohms each, plus you get the ability to balance left to right, fade front to rear, and have more volume.
I just found this thread and have a question.
My 70 Cuda AM radio with factory single front speaker (replacing it with the D-412 Retrosound dual voice coil speaker with jump wires to make it 8 ohms).
The car has a factory rear speaker fader switch.
I have two vintage Kraco 4 ohm rear speakers.
What would the routing diagram look like for this setup? (I'm electrically challenged and need visual diagramatic aids)