Two stereos into one speaker

[chargd72]

Would putting each speaker wire on a Double Pole Double Throw switch work?  Then each radio can remain powered on and functional but only one signal will be channeled to the speakers at one time.  I'm mostly concerned about how much load can be put through the DPDT switches without blowing.  Any feedback on how to make this work would be appreciated.

[daytona71]

chargd72-
First question is why you have 2 radios in your car? 
The idea of switching the output from each radio to a speaker will work, but the radios when powered need to be connected to speakers at all time.  The output transistors may burn out without the proper speaker load attached while powered. As long as the radio you wish to use is switched onto the speakers before power is turned on, it should be fine. Either radio must be powered off before switching speaker load also.
Also, both radios must require the same speaker impedance. The speakers you want to use for both radios must be compatible for both radios. (Usually the speaker impedance required is listed on the radio)

[chargd72]

Thanks Daytona,
My charger came equiped with an AM radio only.  It's in good condition and to keep if functioning just adds to the cool factor, IMO.  Plus I refuse to hack up my cluster to put in something aftermarket.  I will install a small aftermarket FM stereo elsewhere with and aux input so I can run an iPod as well.  And the reason I'd like to keep power hooked up to both units is so it won't loose memory and reset the clock and settings.  So it sounds like as long as I power off before I toggle the speaker output, I should be fine.

Also, both radios must require the same speaker impedance. The speakers you want to use for both radios must be compatible for both radios. (Usually the speaker impedance required is listed on the radio)

Does anyone know the impedance for our factory units?

[twodko]

I'd say 4 ohms. 

[BY RSCO]

Just a thought... not sure if you are looking for more than "just music" in the car or not - a safer bet would be to run the AM unit on speakers in the dash center, then do a set of rear speakers in the package tray with the upgraded unit running them. If you are dead set on running both units to all speakers in the car, there are aftermarket switching units available that will do what you want. On the impedance thing, aftermarket units will comfortable run down to a 4 ohm load (which is what most speakers are), and I would not run the AM any lower than 8 ohms. I am actually going to have an IPOD connection only in the car (running to an amp, then rear speakers) and the dash unit will light up only. I am looking more forward to the sound of dual 3 1/2 speakers turned down under the car  Hope this helps a bit.

[W4ATL]

You should be OK to leave the unused radio speaker outputs open with the switch. I would avoid shorting them out. They may have protection for shorting them out for brief periods but would most likely damage the radio to leave them shorted for an extended time.

I just converted my old radio to AM/FM with Aux input connector so I have the look of the old unit but it can do satellite or iPod with the unit in the glovebox.

[daytona71]

To keep the stock look without cutting the dash or mounting another unit elsewhere, take a look at the following website. I have seen and listened to these units and they are great. The radio when first turned on goes to FM,a quick off/on switches back to AM. You maintain the stock look, (which around here is required if going for collector insurance rates). The units can be 2 or 4 speaker set up. Very loud clean sound. With input jacks for i-pod or whatever included.
Check out Larry's work  at   http://www.woodradios.com/

[mauve66]

You should be OK to leave the unused radio speaker outputs open with the switch. I would avoid shorting them out. They may have protection for shorting them out for brief periods but would most likely damage the radio to leave them shorted for an extended time.

I just converted my old radio to AM/FM with Aux input connector so I have the look of the old unit but it can do satellite or iPod with the unit in the glovebox.

me too, thread is on here somewhere, i'm pretty sure others have also

[W4ATL]

S&M Electro Tech did my radio upgrade. I also purchased the dual cone speaker for the dash to replace the original one that was all rotted. The radio sounds OK with the small speaker but the fidelity of the AUX connector from my iPod and satellite receiver is better. The push buttons and tone control all work and nothing on the radio worked before. It took several weeks (I think about 2 months) for the upgrade to be completed and shipped back to me.

The AUX input is automatic. That means when the radio senses audio coming from the AUX input it will automatically switch to the AUX input. After a time of no music the it will switch back to the radio. I have issues with my iPod on soft passages or between songs it will switch back to radio mode. If you crank up the volume of the iPod too much to fix the problem it will overdrive the radio into distortion. Sometimes the switch happens when I plug in my satellite receiver but not too often since on XM radio they try to keep music or voice on all the time like a commercial FM or AM station - at least on the stations I listen to like Sixties on 6. It automatically switches back when the audio returns.

http://www.turnswitch.com/

[Dino]

I have my original am radio still hooked up to the original dash speaker and my aftermarket radio mounted under the dash going to 4 new speakers.  The only splitter I have is on the antenna.

I liked the idea of keeping the stock system and I love listening to a ballgame on it, it's very nostalgic.

Most of the time I want music though so I just switch to the new stereo.

[bakerhillpins]

Having two sets of speakers, effectively 2 sound systems, is a stellar idea!   

That way I can keep my factory AM/FM as it was and get some tunes from a more up to date source too. It's like cake and eating it too. 

[Dino]

Having two sets of speakers, effectively 2 sound systems, is a stellar idea!   

That way I can keep my factory AM/FM as it was and get some tunes from a more up to date source too. It's like cake and eating it too. 

Sometimes life just works out.   

[chargd72]

I have my original am radio still hooked up to the original dash speaker and my aftermarket radio mounted under the dash going to 4 new speakers.  The only splitter I have is on the antenna.

I liked the idea of keeping the stock system and I love listening to a ballgame on it, it's very nostalgic.

Most of the time I want music though so I just switch to the new stereo.

What antenna splitter did you use?  Where did you get it?

[Dino]

I have my original am radio still hooked up to the original dash speaker and my aftermarket radio mounted under the dash going to 4 new speakers.  The only splitter I have is on the antenna.

I liked the idea of keeping the stock system and I love listening to a ballgame on it, it's very nostalgic.

Most of the time I want music though so I just switch to the new stereo.

What antenna splitter did you use?  Where did you get it?

I bought mine at a local electronics repair store that is now gone.  Looks like this:

http://shop.vetcosurplus.com/catalog/product_info.php?cPath=72_401_134&products_id=9500

It's a pretty simple device, they have these in all shapes and sizes.  Radio Shack may have them as well.

[chargd72]

Cool, thanks!