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Hello this is my first post! I have some questions about my cars audio system. I have a 1971 oldsmobile cutlass and the audio system doesn't work pretty sure it is just my speaker. It has 1 rear speaker and an am radio. i can hear sound from the radio itself but none from the speaker.... should it be a speaker problem? if so where can i get new one? The speaker is stamped 7294892 466120 10 ohm. Also what is the best option for a fm radio? dont want to take original out maybe a mount under dash for new stereo.
Welcome to the site. The speaker is probably no good in the rear. The sound you hear and think is emanating from the radio is actually your blown front speaker. There is no way for the radio to make sound. You may be able to find an AM/FM through the classifieds parts wanted section, they seem to come available regularly. As far as the speakers they are 10 ohm and I don't know the exact sizes, but a simple measurement will net that answer.
Seth if you want an original style speaker replacement try USA Parts Supply. Way down on page 74 of their olds catalog they have this.
SPEAKERS - FOR ORIGINAL RADIOS
S9.651B 67-75 All 3” Round Speaker ............................ 19.39
I recently updated my radio and speakers in my 88. Decided to send my radio out to have one of these installed. Gives me radio, bluetooth, microphone, line in. Its expensive and requires you to update your speakers and wiring to handle modern versions but I think its worth it.
'71 Cutlass most likely has a 4X10 in the front and a 6X9 in the rear. 10 ohm speakers are getting hard to find so in a pinch you may be able to replace with 8 ohm if you can find them in the right size. I never had any trouble with using the more popular 4 ohm speakers but your radio amp may run a bit hot if you play it at higher volumes. If you cannot find the correct 8 or 10 ohm speakers an alternative would be to use 4 ohm and add a small inexpensive modern amplifier in-line to compensate. The stereo/radio can supply input signal for the amp without overheating and the modern amp will power the 4 ohm speakers without any difficulties.
Couldn't you just get a 2-ohm resistor and put it in series with an 8-ohm speaker to create a 10-ohm load so the radio has no problems driving the speaker?
8 and 10 ohm speakers are getting harder to find. There are some aftermarket co's selling some. Do not use a 4 ohm speaker wired to the radio alone as the amp in these old radios will not tolerate them and will burn out the power transistors.
Couldn't you just get a 2-ohm resistor and put it in series with an 8-ohm speaker to create a 10-ohm load so the radio has no problems driving the speaker?
Originally Posted by oldcutlass
8 and 10 ohm speakers are getting harder to find. There are some aftermarket co's selling some. Do not use a 4 ohm speaker wired to the radio alone as the amp in these old radios will not tolerate them and will burn out the power transistors.
In theory, yes. But in 15 years as a professional stereo installer I never saw one stop working because of the speaker load. It was common to replace the factory speakers with 4 ohm speakers without damage to the factory stereo. The static impedance of a speaker is not the same as the dynamic load it puts on the amplifier. The impedance changes with the frequency and volume of the input so playing a 4 or 8 ohm speaker at low to moderate volumes should have no ill effects on the factory radio. Heat is what damages the transistors so as long as you don't play Metallica at maximum volume for extended periods of time and overheat the amplifier section of the radio you will be ok. Adding a 2 ohm/20 watt resistor in series with the speaker will increase the static impedance of the speaker but it will only reduce the speaker volume, not increase the dynamic impedance. It's like putting headers and dual exhaust on a stock engine, as long as you don't over-rev it it actually improves the performance of the engine.
You can also just run two 4Ω speakers in series...
But then you would need places to mount TWO speakers for each channel, and how often do you have room for that if you're trying to maintain a factory look? Why not just put a 4-ohm resistor in series with one 4-ohm speaker? The resistor could be soldered right to the speaker terminal.
Why not just put a 4-ohm resistor in series with one 4-ohm speaker?
Because, for one thing, you will reduce your sound output by half.
The OP is asking about a car with a rear speaker. He could just wire the front and rear speakers in series and have 2 4 ohm speakers.
If only using the front speaker, he could place two smaller (but acoustically superior) speakers in the original opening, or wire one in the opening, and one under the dash.
If using a rear speaker, he could place a 4 ohm 6x9" speaker in each cutout and wire them in series.
Or he could just install a modern stereo with the components concealed, which, to me, is much more fun.
Because, for one thing, you will reduce your sound output by half.
But that may still be more than enough volume. It may be worth the cost of a $1.00 resistor to find out before going through the trouble and expense of purchasing and mounting a second speaker.
The OP is asking about a car with a rear speaker. He could just wire the front and rear speakers in series and have 2 4 ohm speakers.
Not if he wants FM, which he says he does, and presumably that would be FM stereo. I presume he'll want to use the front speaker as one channel and the rear as the other.
Not if he wants FM, which he says he does, and presumably that would be FM stereo.
Most FM radios "back in the day" were not stereo, and he says he is using an original radio, and mentioned a single rear speaker, so that is not stereo.
Like I said, I'd just install something newer, but we all have our priorities.
I would guess that, by the early '70s, most people opting for an FM radio would have gone with a stereo radio. Regardless, if it were me, if I'm going to look for a year-correct FM radio for a '71 Cutlass and have some semblance of a chance of actually enjoying the sound, I'm going to look for a stereo radio.
He did ask for the "best option" for an FM radio. Regardless of whether or not he goes with a year-correct in-dash unit or an aftermarket, under-dash unit as he mentions, I think the first answer to this question is, regardless of which way you go, get a stereo unit. This is, after all, 2016, not 1971. All FM stations broadcast in stereo now.
The best option is to install an amplifier or two out of sight in the trunk or under the seats, install small tweeters in discrete locations, such as behind the original dash pad corner perforations (depending on exact make and model), install midrange speakers somewhere non-destructive, such as in aftermarket kickpanel enclosures (thus preserving the originals) and behind the package shelf cutouts, stick a small subwoofer in the trunk, and run the whole thing off your phone through a small concealed "head unit," without even wasting your time with inferior FM radio signals, but, like I say, everybody has a different idea of what's "best" when it comes to sound, as they do when it comes to other things.
But then you would need places to mount TWO speakers for each channel, and how often do you have room for that if you're trying to maintain a factory look? Why not just put a 4-ohm resistor in series with one 4-ohm speaker? The resistor could be soldered right to the speaker terminal.
The resistor pictured above will not work. It is a 1/4 watt resistor and in a speaker system you would need at least a 10 watt resistor. You would need one like below. But for the purpose of increasing the dynamic impedance of the circuit, it would only reduce the output of the radio by half. Not a good idea. Like I mentioned above, I have never seen a factory radio quit working because of lower static impedance speakers. Just hook up new speakers and be done with it. Or like Eric says, install a modern stereo system in a stealth fashion and enjoy your cruisin' tunes even more.
okay cool thanks everyone!! I can not find where the front speaker is located though.
You will probably have to remove the radio to find it. It should be a 4X10 speaker mounted to the underside of the dashboard. If you have A/C you may have to remove some of the air ducting in order to actually reach it.
