Hi all
I am trying to find a new pair of speakers from my stock Oldsmobile 1970 AM/FM Stereo radio (Two piece version).
The rumor specifications indicate that this radio with the Delco DS-503 Transistor, put out approximately 5 watts per channel?
This radio is designed to support 8-10 ohm speakers only.

The problem is that 99% of the On-line car stereo shops only sell 4-ohm speakers. And most of those speakers require 10+ watts to drive the speakers.

I did find one place that sold a low end pair of speakers for $104.00.
I am looking for more options.
Thanks.

Miles

 

I just looked around on Crutchfield and I see what you're saying on 4 ohm being all that's available. FWIW Crutchfield has a lot of decent 6x9 speakers for way less than $100.


You may have to put a 4 or 6 ohm resistor on the speaker + lead. That should get impedance where it won't damage your output transistor.


Rob72lady71 can probably help you out on this but just searched and can't find him?

 

I used 2 6x9 4 ohm speakers in the back of my Olds. If you bring 2 wires to the back and 1 wire goes to the + side of one speaker then the - side of that speaker goes to the + side of the other speaker then the - side goes to the radio. 2 4 ohm speakers in series adds thus you have 8 ohms. I did this 2 years ago with my Olds am/fm radio and it's worked fine.

 

Apparently 8ohm speakers are obsolete. You may have to settle for the pair you found. There are some custom speaker places but the price range is going to be what you already found.

 

You might check out turnswitch.com.

http://www.turnswitch.com/speakers.htm

 

Hi Don:
That is the company i have been searching for, but could not remember their name.
Thanks. Ill drop them an email and verify they will work with a 5 watt amplifier.

PS, I have used their front dash replacement speaker (dual speaker) with good results.

The stock AM/FM, is currently driving the front 4x10 Dual speaker in the front (wired up in a 8 ohm configuraiton) and driving 1 old back deck 6x9.
The goal is to convert to a pair of deck 6x9.

 

X2 these guys...this is what I run in all my cars front, rear, whatever.

 

http://www.ebay.com/itm/NEW-6x9-Subw...sAAOSwo6lWH-3y

 

Way too much speaker for the stereo.

 

X3

The magnet technology alone is worth a little extra $$

Give them a call; five minutes in you'll see that this guy's top notch. He'll tell you all about proper ohms and why they are necessary.

These pics are of a '72 Corvette I am working on. Look at what is stamped top; "do not operate without 8 to ten ohm speaker"








Would anyone happen to have an extra female plug for the app in the pic?

 

Speaker update:
The speaker install was successful
I installed a new front speaker with dual 4 ohm speakers in the front and a single 6x9 in the rear from Turnswitch.com.

For the front dual-speaker, I attached a separate cable to each speaker approximately 3 feet long. Then I wired the speaker cable ends in Series to make 8-ohms. Now I had the option of running the speakers as 8-ohms for my stock Delco radio or I can split the wires and run as two 4 ohm speakers for a Modern radio.
Since each speaker has a dedicate cable, I not have to remove the speakers to switch from Both running in Series to two independent 4-ohm speakers.
I installed 1 low wattage 8-ohm 6x9 speaker. I ran a pair of dedicated speaker cables under the carpet to the rear just in case I want convert to dual rear deck speakers. The Rear Deck Metal is pre-cut to support two 6x9 speakers. The cardboard stock cover was only setup for 1 speaker, so I kept my car stock and just installed 1 speaker.
My 1971 CS came with an AM radio (Dual speakers, 1 front and 1 rear passenger side).
Now I have stock 1970 Delco Oldsmobile AM/FM radio, designed to also use 1 front speaker and 1 rear speaker.
Converting from a stock Delco AM radio to a 1970 Oldsmobile AM/FM radio (With separate multiplex) took about 12 hours of labor. I did take a lot of pictures, but can't seem to find them today.
Why did it take so long?
Mounting the Multiplexer over the glove box was very time consuming. And you have to wear gloves at all times, otherwise you will donate a lot of blood and skin to the sharp metal dash. Next time, I'll just fork over the $625 and buy an Oldsmobile clone radio.
Remove passenger Seat. Remove AC ductwork. Remove Glove box. Remove AM Radio, Save and mark all screws, etc. (The center speaker I had already replaced).

Install new AM/FM Radio, Install Multiplexor close enough for the short 12-inch data cable to reach. I re-used one of the glove box latch screws to hold 1 of the Multiplexer mounting brackets. I then installed a flexible metal pipe strapping to the Multiplex and to the dash frame to support the back of the Multiplex. The mounting seems secure enough.
I am convinced the Multiplex should be installed before you install the dash!
I think I did spend more time trying to align the Glove Box hinge plate than it took to install the Multiplexor. Tip, use the short self-tapping screws for the Glove Box hinge plate and not the long ones. Else get a file and black paint to repair the hole in the dash when the long screw pops out the bottom of the dash.

Then put everthing back in the correct order and you are done.

The first road trip went good.
Contrary to my wife's theory, I could still hear the radio over the Exhaust. The radio only puts out a maximum of 5 watts per channel. The FM sounded good at highways speeds. Not as good as a modern radio, but much better and listing to the 1 foreign language AM station.

http://www.vintageautoradio.com/

 

Nice post Miles.

Isn't it nuts how far technology has come? This '72 Corvette had an aftermarket radio. I installed the original back into the car for him. It is a three piece; main unit, multiplex unit, and heat sink unit. The multiplex unit is heavy and the mount screws only go into sheet metal. I had to get creative to make it fast. I used new 4X6 speakers from Turnswitch.

I would have never guessed it would be so complex. This had to be why it took the factory so long to offer FM/FM stereo in the Oldsmobile A body.












.

 

Just wondering, when you refer to the 2 piece version....is that other piece the "Delco Stereo" box that I have on my car? Just wondering what this box does...if it was an amplifier or some sort or just makes the stereophonic sound work. It is the little black box on the lower right in the picture. Also, any idea on what this box is worth?

 

Hi W30, the Image is too dark for any details. Maybe yours is mounted under the dash?
Most of the time it's just above the glove box.
The 1970 multiplexor is approximately 8" x 8" x 3" in size.
The Receiver supports the Left Channel and the multiplexor box supports the Right channel. Each channel is rated at approximately 5 watts.

Here is a picture of what the multiplexor looks like install.
https://classicoldsmobile.com/forums/general-questions/103161-1969-olds-442-mutiplexer-radio.html

 

Yes, it appears to be the unit here: http://i.ebayimg.com/images/g/cqMAAO...Z7/s-l1600.jpg

 

Wow, I never knew they had an external box option for the multiplexor, but it does make sense. That way, they could sell it as an aftermarket and bolt it under the dash. Its not practical for a dealer to rip apart the dash to install the Multiplexor above the glove box.

Did that external box come with the car when it was originally sold?

Since the box is most likely the external multiplexor for your Rear Speaker, you do not want to remove it unless you are going to also dump the 8-track and AM/FM receiver.

A complete Oldsmobile AM/FM 1969-72 vintage system that Works, are selling between $200-400. There are some Condition unknown radios for less.
Since you also have an 8-track, the whole working system would be worth $300-600.

Now you can buy a Clone that looks almost identical to your existing Olds AM/FM. The clones support 4 speakers at 40 watts each. Sorry no 8-track.
Price for the clone is just under $600.

 

Thanks for the detailed info. I plan on getting rid of it all and putting it back to the original AM. None of this setup came with the car originally. This car had very few options. It was meant for speed and that's about it. Comfort came later.

 

It was a Tight fit under the glove box.

#1 This is the top latch for the glove box. I used one of the latch screws to secure one of the Multiplexor mounting tabs. There was no way to secure the second mounting tab to the right with the dash fully intact.
#2 Power Transistor for Rear Speaker (Delco DS-501, made in 1968, Week 42).
#3 Power and data connect to Multiplexor, from the Receiver (#4). This cable is very short, not many choices for mounting the Multiplexor.
#4 The Receiver (The Box with the volume/tuning *****) and amplifier for the Front Speaker.
#5 Blue wire for the Rear Speaker.
#6 Two Speaker cables, that connect to the dual 4 ohm speakers mounted above the receiver.

 

After the Multiplexor was fully strapped in and tested, I removed the temporary support wires that were used to hold the Multiplexor in place while I figured a secure way to strap it down tightly.

Glove box view, just before I re-installed the Glove box. The actual glove box did clear the Multiplexor by a few millimeters.

 

Just to add to this thread, the "two box" stereo design was simply an expedient way for GM to provide a stereo option in a time when few people cared about it or ordered it. The in-dash unit incorporated the tuner and one channel, same as a mono radio. This powered the front speaker. The low-level output for the second channel was output from the dash unit and wired to the external multiplexer, which was simply a duplicate of the amplifier section in the dash unit. This second amp powered the rear speaker. The Delco radio service manuals have nice schematics that show how these are wired.

 

Yeah, I wonder how many radio stations were even broadcasting in stereo in those days. Nice pics and breakdown of how it all is laid out.

 

That's interesting Joe, I was puzzled over the term "multiplexer". Sounds like more of an Amp deal. Hmm, that would mean the Stereo field would be Front/Rear not Left/Right. Wow.

For sure the AM (mono) band would have been more popular in the day. I remember FM being Elevator tunes back then!

 

The cost for the AM/FM stereo radio was very expensive in the 69-72 cars, with many instead ordering the AM radio with the 8-track player, which included front and rear speakers. It was not until 1972 that Oldsmobile started offering the AM/FM radio in the less costly monaural version as well as the stereo version.

This company also sells correct speakers: http://www.turnswitch.com/radio1.htm

 

I am not a 68-72 expert, but I believe FM was a big car option in 65 or so. I do not know if it was a 66 option, but, for 67, the Cutlass could have an AM/FM radio with one speaker output.

The 66/67 Olds A body radio, maybe along with others, had one powered speaker out that came out of a connector behind the tuning ****. This came default with a jumper that would shunt it into the main harness to power the front speaker. There was an addon **** to replace the dummy **** behind the tuner that was a self contained potentiometer that, when plugged into the aforementioned two connections, and a third below it, would bridge the power between the main harness for the front speaker, and a standalone lead for the rear. This was the Bi Phonic Radio Adapter, option B-51 I think.

Now what was really cool is that, before stereo, they had this reverb accessory that would jump in between the connection for the rear speaker, and, via a powered amp, delay the signal for a bit. You could switch it off or on. I've got one, it's going in the restoration project. I heard that it's good for guitar solos.

 

You can listen to Crimson and Clover by Tommy James and the Shondells ...