How To Repair and Diagnose Problems with Your Imperial's Speakers 

Imperial Home Page -> Repair -> Accessories -> Radios -> Speakers

Tips from Arran:

One thing that I have noticed is that speakers that are mounted facing upward tend to have more problems then those mounted in the vertical position. The speaker for the radio in my Imperial is in perfect shape and is so because it is mounted in the front of the dash rather then on top. Even without the heat the horizontal mounted speakers tend to collect dust which often works its way in between the voice coil and the pole piece causing a grinding noise. If the dust doesn't work its way into the voice coil it still makes a rattling noise from the dust bouncing around in the cone. The only exception seems to be if the speaker has some sore of baffle on top of it to reflect the sound to the side. These baffles seem to prevent the dust from getting into the speaker as much since they are usually mounted inside of a cabinet that encloses the speaker. But since your car speaker only has an open grille on top it will encounter not only the dust problem but the U.V. light braking down the cone. Back in the mid thirties it was quite popular to mount speakers in this fashion in house sets, needless to say this trend didn't last long. Not only did they have the dust problem, that I described, but they usually had the speaker mounted over the tubes which produced enough heat to broil the cone. Another factor that probably killed the idea was the fact that you couldn't put anything on top of the cabinet or put the radio on a bookshelf as the sound would be blocked, they didn't have those deflecting baffles in those days. The auto industry started mounting radio speakers in the horizontal fashion in the late fifties, I guess for styling purposes. In spite of the fact that they encounter the same speaker problems, as previously described, they still continue the practice. Obviously they have learned nothing after several decades of experience, if they did they would mount the speakers in the kick panels as a standard rule.

Addition from John:

The original speakers had a piece of cloth glued over the front to keep objects from settling on the cone & rattling, but of course, most are likely rotted by now. If you put in new speakers, you may want to cover them in the same way.

Addition from Kenyon:

Reduce the chances of noise-making debris & dust collecting in your new horizontally mounted speaker cone by covering with a piece of pantyhose if you want to reduce the chances that you'll have to take the grille cover off for later cleaning. 4 years on one of mine and it sounds fine.

Acoustically transparent and less than the grille cloth sold to cover speakers in the store.

I used black, stretching around and fastening with crazy glue and stayed away from the fish-net style.

Question from Hugh (1958):

I am most interested in how to put in some speakers without cutting anything.

Reply from Kenyon

As mentioned earlier, if you can find a space for speakers, such as firing down from behind/up & inside the dash or in the stock hole in the dash/package shelf, but there is no anchor point, or the speaker that you desire is smaller than your exiting hole, you can go to a shop that does metal heating ducts and they can fabricate some sheet metal forms that you can bolt to your car's structure, and then bolt the speaker into.

This worked for me when I put a non-stock Radio Shack speaker into the odd-shaped dash hole of my '6o. The speaker was a different shape and slightly smaller than stock. Stock was very ovoid and not really available anymore, as a general speaker shape.

When installing speakers, please keep in mind that they work best if the air touching the front face of the driver is isolated from air of the rear face, just as they are in your home speakers, or any car speakers that you can think of that are placed into panels.

They are placed in such a way that they are surrounded by the plane that they are bolted into, that way, when the driver vibrates, you are only hearing the positive end of the vibrations, and the negative, or opposite, throw of the speaker cones is sent into the door or the airspace under the package shelf, or whatever the speaker happens to be bolted into. Sound is, after all, air being vibrated into waves at frequencies that our eardrums translate into signals that are understood by the brain.

It is possible to have soundwaves that are opposite of each other cancel each other out, and having a standard speaker driver (just hanging in space under your dash) allows this at certain frequencies, which is why you almost never see just the cone & basket of a speaker mounted freely and alone, as opposed to having it mounted into something.

As an aside about opposite sound frequencies canceling each other out: this is called "Active Sound Cancellation" and has several other marketing names. Bose recently tried this with Lexus, with a microphone in the car, and the sound system pumping out negative, canceling sound waves that dropped road and engine noise to nearly undetectable levels. I got to ride in/listen in a propotype, and it was very weird to be in a car that was completely silent inside. I could hear my wristwatch at 75 mph with my hand next to my thigh. Focus groups felt wierded out by it, and a limited version went into a few models, but I think that it has been abandoned due to benefit vs. cost not being a selling point.

Speaker Selection: When looking around for a speaker set for your car, note the design characteristics of the existing driver that you are replacing. The one that came in my 196o had a magnet that was about 1/4" and is pretty thin by modern standards.

When looking for a replacement, try for something similar. Radio Shack has cheap speakers that have thinner magnets. Buying a more modern premium speaker with a heavier magnet will take more energy to produce the same volume, and will yield better deep sounds. The deeper the sound, the more energy it takes to make the sound, and the deep sounds take exponential amounts of energy to produce higher and higher volumes. Hence the huge amplifiers and speakers that the small-car guys use. If you keep your stock radio, make sure that you keep it connected to a speaker that will not require more juice. It sounds relatively tinny for these reasons.

Fortunately, the radio that is stock in our cars is good enough for most Imperial owners and for playing Frank Sinatra as you drive. If you want sound that exceeds 19xx technology, be prepared to use your stock radio as a receiver/tuner only, and to bypass the unit's amplifier, as it will get overloaded and burned out if it is required to drive speakers that are "heavier" than the unit is capable of driving.

I am in the audio-visual industry, and many are baffled by it. Please for give the length of the script above....

Question from Tony (1961):

Having done most of the major restoration on my '61 Imperial, I am now sorting out some of the little jobs that I have been putting off. One thing that needs attention is the front loudspeaker. It has been replaced with a modern one and it sounds awful. I would like to find a more appropriate speaker. Does anyone know what the correct specifications would be? How many ohms etc?


From Dick:

If you have the original speaker from the car, you can have it rebuilt by a vendor who specializes in that service.

As for the impedance, this is not really critical, but anywhere between 4 and 12 ohms should work fine. The original spec was probably 8 ohms. This is not a resistance that you can measure with an Ohmmeter, by the way, as it consists of a resistive portion (which you CAN measure; it will be around 2-3 Ohms, probably) and an inductive portion, which you cannot measure without special test equipment.

From Kenyon:

To replace my 1960 speaker with a new one, not being able to find one that matched in shape, I:

Went to Radio Shack with the old one. It was a hyper-oval shape and quite "funny" in relation to what has been standardized on today.

Got a new, cheap-o, round (that's important) car speaker that had the same diameter as the narrow section of my oval OEM speaker.

Went to a heating and ductwork place with speaker and a sheet of paper on which I had impressed the shape of the opening in the dash by running my fingernail around the shape and embossing the dash-shape and mounting screw holes into the paper template.

They cut a piece of sheet metal that was soft and wiggly into a shape that was slightly larger than the hole in my dash. They then used a duct hole cutting tool that worked not unlike a compass that you put a pencil into. The hole matched the speaker perfectly.

I then drilled pilot holes for mounting the plate to the dash and the speaker to the plate.

Spray painted the plate flat black.

Lastly, I used silicon goo and screws to mount the plate to the dash and the speaker to the plate.

All speakers operate on the principal that the front and back faces are acting against different bodies of air A speaker that is freestanding, or has spaces around that allow air to pass between front and rear areas, is terribly inefficient (that's why speakers are always "installed" into something unless they are horns or membranes). Sealing the speaker into the dash is important, be it with foam gasket material or goo or whatever.

The radio sounded fine for an AM unit, and I was out about $20. The speaker was only visible through the grate on the dash when viewed from above and the black paint meant that I was the only one that ever noticed because I went out of my way to inspect it.

Question from Jay (1962):

I have had the AM radio and speaker out of the dash of our '62 for over a year now. The 40 year old speaker cone turned to dust, prompting me to remove all the audio components for R&R. A while ago I cleaned the radio real well, lubed the mechanical parts, and refreshed the orange Day-Glo paint on the dial pointer. For fun I did the same to a spare '63 radio that I have.

I have decided to pursue the rebuild or replacement of the speaker, the last hurdle to getting it all back together again.

I talked to one shop in Colorado (advertises in Hemmings) and they told me if the speaker is the round 7" OEM unit that Mopar used for many years, that they didn't have the resources/materials to rebuild that specific type of speaker! When I got home from work I measured the speaker. To my dismay, it measured exactly 7" across the frame. =8^(

Does anyone have any experience getting this type of speaker rebuilt? Any suggested resources?


From Dick:

There was an outfit in the Riverside CA area that would recone any speaker. Are they one of the ones that has gone out of business? If so, I suggest you go to:


I think you'll find what you want at either place. I've done my own, but I'm not looking for any more projects.

There are many others still in the business, these just popped up first.

From Mike:

Any good audio shop should be able to fix you up...they can recone a speaker, put in a new voice coil, etc. Thing is, its often more expensive than just buying a new speaker, and nobody will see it- its under the dash!

Another interesting tip I heard is that two 3.5" speakers will fit into the oval cutout in the dash of cars with 4"x10" speakers. This way you can wire both channels into the dash without cutting new holes.

From Philippe:

A friend of mine sent me a catalog for CH*"Y truck (no interest for me) but on it I've seen a "dual voice coil speaker" designed to fit in the original location. But I don't know size.. This speaker is stereo and you can connect it to a modern stereo system. It handles 120 W, more than the original speaker ... Price is around $ 60.00. Fit 47-53 or 55-59 trucks (2 references: 38 8560 or 38 8561). Seller is LMC truck, 800 222 5664.

Question from Bob (1963):

Has anyone installed speakers in an older imp convertible? I am trying to find a set of speakers and place to put them without disrupting the stock interior.

I'm getting a little tired of the AM radio and speaker in the dash although it is nostalgic when cruising.


From Arran:

Perhaps speakers could be mounted behind the kick panels? In the older cars they are made out of thick cardboard with carpet sewn on top. All that you would have to do, if you have these type, is cut holes for the speakers, in the appropriate spot, before the carpet is sewn over. The sound would be blocked a little but at least the speakers would be hidden. It would also help to pack some sound deadening insulation in the cavity behind the panel so it doesn't reverberate off the sheet metal.

From Mark:

I've been wrestling with this myself. I'm looking at mounting speakers underneath the rear seat pointing forward. Sound will be blocked by the seat material though.

From John:

I've seen many use Kicker style boxes placed on the rear floor & using a quick disconnect plug to remove them easily when not in use. You could also place them in the trunk. With a convertible, much of the sound will still be easily heard.

From Chris:

What I did was build some custom boxes out of sheet metal the size of the stock openings on the rear deck. I insulated the insides of the boxes with foam rubber to prevent any distortion. One box I configured with two openings so that it would accept the stock speaker. The other one was just a box with a single opening. I didn't want to do anything to the package tray or rear deck as far as grilles. I also want to keep my Imperial stock looking. So I epoxied some 8-32 bolts to the speaker locations (I did not want to weld anything inside the trunk.)

The speakers are powered by an under seat mounted amplifier which receives its music input from an MP3 playing portable CD player. On one recordable CD you can have up to 27 hours of music that way. Since the input to the amp is an 1/8" jack, you can connect practically anything to it (walkman, audio out of a lap top, etc.) and get sound out of the speakers.

Question from Henri (1965):

In my '65 Crown I still have the original radio. I have the option (?) for the rear speakers with the fade knob below the dash. But somewhere in time the took out the rear speakers. Can I hook up just normal 4 ohm speakers? I have some nice Caliber 3 ways who would fit nicely


From Kenyon:

4 Ohm should be fine.

Newer speaker design has changed from older to allow/expect higher power output amplification sources. This comes in the form of thicker magnets that allow higher volume of the lower frequencies with less distortion.

A thicker magnet draws more energy to produce an equal amount of sound. Therefore, thin magnets on your front speakers will not do bottom end loudly as well (bass requires an exponentially increasing amount of energy the deeper/louder that you go).

Matching 2 different grades of speakers F+R will cause your original radio to work harder to power the rears or may overdrive the fronts if you do not adjust the fader to boost the rears to match the more efficient front units. Probably not a big deal, but you could cause the radio to work harder than needed to supply you with the volume that you desire if you don't get close to stock grade speakers or match all 4 with newer units that do less absolute volume overall for the power that you have to give them. It was 1965, remember, and audio-philes were using lamp-cords for speaker wire at that time, so, modern equipment is pretty different, especially where speakers made in the last 15 years are concerned.

Don't know the output of the factory radio, but be sure to compare the thickness of the magnets on new and old, and the closer to original, the better. I went with some cheap (under $20) Radio-Shack units and they were great for the 1960 with AM-only that I did. Dean Martin doesn't do the thumpa-thumpa music, anyway.

From Bob:

Your original radio is not stereo, so if you want to hook up more than one rear speaker, you'll need to wire the speakers in parallel. I've long forgotten what this does to impedance (the total ohms that your radio "sees"), but such a hookup can get make the load too low and draw too much power from that old unit. It would be better to check the resistance rating of the original front speaker and match it with a single rear speaker - probably 8 ohms.

From Mike:

Any old speakers might work, BUT...

Your radio is only meant to "see" a certain number of ohms...too few and it will burn up! Back in the old days of lo-fi, 8 and even 16 ohm speakers were common. Nowadays, 4 ohm is the standard and I've even see some 2 ohm setups. (BTW and Ohm is a unit of resistance, V=IR for those who know, R= Resistance, I=Current, V=Volts. Drop the resistance and the current goes up with constant voltage)

I'd go find a pair of 8 ohm speakers, and hook those up to the current setup. If you want to wire the 4 ohms up, I'd wire them in SERIES, thus adding their resistance to 8 ohms. Wiring them in parallel will give an effective load of 2 ohms and blow up your radio.




"+"-------+speaker------"-" | | |----+speaker-----|

Question from Jason (1967):

Anyone know the replacement size of the factory dash speaker? AND a good place in So Calif to buy 1?


From Dick:

Sorry, Jason - I don't think they are available anywhere. The closest one I could find was a 4"X10" one at Radio Shack, which I had to modify by cutting up the factory speaker and tack weld to the new one to use the existing screw locations.

If your old speaker is physically undamaged as to the metal parts and the voice coil, you can have it re-coned - there are services that do that. A google search should turn up a vendor, and I think there is one listed on the IML vendor list.

From Kenyon:

These are a funky size and probably unobtainable.

I took the old basket out of my 1960 and took it to Radio Shack. I bought the cheapest round speaker that I could find that did not exceed the original in diameter. You want cheap as the radio deos not have enough power to drive a more modern speaker with a heaveier magnet. Look at what comes out for reference. Look at the magnet on the new ones and get the smallest magnet that you can.

I then took the original and new items to a place that does furnace ductwork.

They were able to cut out a piece of thin sheet metal slightly larger than the original speaker. They then had a tool that would cut a hole (any size) in the sheet metal correct for the speaker. Drill some holes in the sheetmetal to mount the speaker, drill some holes in the sheetmetal that equal the original speaker and you're almost done.

You want to spray the metal black. Then use silicone to seal the speaker into the metal and the metal onto the dash, as you want the air that is vibrating on one side of the speaker not to be in contact with the air on the other side of the speaker as it operates, just as on your home speakers that are in boxes.

Screw in and you're good to go.

If you're really precise, you can cover the rig with black speaker grille cloth, but the stock speaker grille should obscure your work if everything is sprayed black underneath.

From Paul:

The best thing to do would be to recone the speaker that came out of the car. You can probably do it yourself, or you can have it done. That way you can be sure that the speaker is the one that fits the vehicle, in both size and power. Installing the wrong power speaker can damage the radio.

If the cone isn't too bad, and you don't want to spend any money, nine times out of ten you can repair the old cone with toilet paper and 3M Sprayment. I did that to the front speaker in my '62 in 1979 and it still sounds great! Back then I had NO money to do anything. I only paid $100.00 for the whole car, so I certainly wasn't going to spend $10.00 for a speaker, especially one that didn't fit the hole.

I planned on changing that speaker last summer when I was doing so much work on the car, but it still plays so well, I have left it alone (for the time being).

Question from Don (1967):

Let me ask the experts on the rear seat speaker for my '67 convertible. The rear. as opposed to the front, was a standard size which I picked up
at Radio shack, my questions:

1) How am I sure the speaker is connected correctly (polarity)?

2) I did not get a "small magnet" but the radio seems to drive it OK (except front to back balance favors the front speaker) what is risk of driving
the larger mag?


From Dick:

Magnet size is not a factor, the only factor is the "impedance" of the speaker voice coil, and that is very uncritical also, unless you are driving it with a super high power BOOM box of the type used in the high school kid's Honda Civics with the chrome wheels and the 6 inch diameter exhaust tip. Any speaker with an impedance of 4 to 16 ohms will work just fine with your radio - the impedance is on the box it came in, and is probably either 4 or 8 ohms. The only thing that will bother the radio is a dead short on the speaker wires, or running it with no speaker at all. The output circuit is a single ended power transistor - it isn't particularly fussy or delicate as long as the power polarity isn't reversed, and the output is not shorted to ground.

Magnet size on a speaker is the new "horsepower" race amongst the speaker vendors - they all claim to have a bigger magnet than the next guy. The size of the magnet is not the important factor, but the uniformity of field strength over the voice coil motion range is, and larger magnets tend to do a better job there. However, the older speakers used pure metal magnet, while the new ones are ceramic - which have to be bigger to produce the same flux in the gap. More flux makes for a better energy conversion from current in the voice coil to sound level (read "louder music at the same volume setting").

The marketing guys turned this larger magnet situation into a whiz-bang new hype. Ignore it.

All you care about on a speaker is the cone resonance, the maximum power handling capacity (only if you are driving it with a monster amp), the frequency range, and the harmonic distortion. None of these are important for a car radio from the 60's, believe me!

My '67 convertible also tends to favor the front speaker with the balance control set in the middle, especially with the top down. However, I have had people tell me the rear speaker is too loud when the top is up and there are people in the back seat, so I have to re-adjust the balance control. I think the front windshield/dashboard creates a projection device that helps the radio volume for the front seat passengers. I guess that is why they have a balance control - I get the same complaints in my Limousine (the '47 Packard).

From Kenyon:

No risk in using a larger magnet, I should think, just not so much volume.

Smaller magnet takes less electrical force to vibrate. It will thus go louder with a particular amount of current. Your front speaker "weighs" less to push around and thus goes louder when run in the same car with another, more modern speaker that "weighs" more.

You should be OK.

I suggest the smaller speaker magnet based on the assumption that giving the radio as close to what it expects and was designed for is the safest way to insulate myself from some principal or limitation unknown to me that could cause problems. I work in the Audiovisual business, and know of no reason that this could be a problem, but as with mounting larger or smaller tires onto a car where the speedo is thrown off as a first sign, you never know what else is wearing that is unseen.

The guys that have the compact trucks that have the great big tires, for example are wearing their drivelines at an accelerated rate according to a buddy that's into that sort of thing. The engineers intended the driveline to have a certain size or range of size tires, and exceeding that induces accelerated wear. Hence the aftermarket parts to beef things up.

I have to assume that the engineers "expected" a certain type of speaker, and tried to get as close to that as possible to try to avoid later headaches. This goes along with the thinking that you rarely see old cars that were previously modified for sale (hotrods excluded), like the Chargers with the huge tires and such from the 1970's. It's the original survivors that are left stock that have the highest chances of survival as they are left to do what they do in the configuration that they were designed to be in. Hope that makes sense. I REALLY, REALLY don't want to start debating what aftermarket parts do to various cars, just trying to support my logic for sticking as close to the original design as possible.

Don't worry about your "different" rear speaker unless you want to.

From Paul:

The polarity isn't critical, but the speakers should be "in phase" to function properly. That means that they are hooked up the same way. When they are out of phase, one speaker will vibrate the opposite of the other. An easy way to test this is to hook it up one way, turn up the base, if the base comes out the back, it is backwards. Both speakers should be connected in such a way that the base tone emanates out the front of the speaker.

If the original speakers didn't have different connectors for plus and minus, or if they are not colored or labeled, it really shouldn't matter, but I generally check it anyway.

If your radio is designed for an 8 ohm speaker and you install a 4 ohm speaker you WILL damage your radio. It is absolutely critical that you install the correct impedance speaker for the radio in your car. If your radio is designed for a 4 ohm speaker and you install an 8 ohm speaker, the radio will not be damaged, but the sound quality will suffer.

Follow-up from Neil:

A simple way to check which terminal is which on a speaker is to connect a c or d cell battery to it briefly, if you have the + to the + the cone will move out, if you have it the other way round the cone will move back, mark the speaker with a permanent marker as to which is which terminal and bob's your uncle as we say over here.

Follow-up from John:

If the speakers are out of phase, you will get very thin sound with virtually no bass output. If in doubt, reverse the wires on 1 speaker only & see which way sounds better. A speaker with a larger magnet is generally a higher performing speaker. It will take a bit more power to drive it then the one with the smaller magnet.

Question from Roger (1968):

My '68 LeBaron would also appear to have too many speakers. She has the AM/FM search tune radio with the foot button, but also has the two small square speakers in the front doors. At the rear, she has one speaker because the right side is taken by the rear defogger. Her Certicard says she belonged to Chrysler Motors, Dallas, TX.

I hope someone who has the secret decoder ring can tell something useful from the broadcast sheet. Under Radio it has 425, then under Rear Speaker, 426. Finally, under Stereo Radio Stereo Tape it has 427.


From Dick:

Since you have the stereo speaker setup, your car must have had the 8 track player from the factory. If you look at the underside of the lower dash, over the transmission hump, I'm betting you will see 3 screw holes from the mounting bracket. Take a look at the unit mounted in my car, you'll see the location of the three screws.

If this is the case for your car, you probably also have the other components, hidden out of sight in your dashboard. The crossover network will be found behind the glove box, mounted to the cardboard of the glove-box with two screws. It has a 6 terminal connector. The fader control next to the power antenna switch will have 6 wires instead of the usual 3 wires (it is a dual gang potentiometer). If you have all those items, you have enough to install the system in your car. You'll have to lose the rear defroster, though, to get good stereo, as you'll need both rear seat speakers. I doubt you need it very often in Phoenix! I also wonder why it was ordered for a Dallas car.

To follow where all the gadgets and wires go, consult page 8-107 in the 68 FSM, and my info on the web site for mounting locations and cable routing.

As for the numbers on the build sheet, I can only guess that the 427 refers to the rare Chevrolet engine option, and the 426 refers to the special Hemi heads, while the 425 was the departure time (actually 4:25 PM) of the train on which the car was shipped to Dallas.

From Bill:

Radio - 425 : AM/FM Search Tune 

Rear Speaker - 426 : Rear Seat 

Radio Stereo Tape - 427 : Auxiliary Unit

Question from Brad (1974 interchange with 1978):

The speakers that are mounted in the rear package shelf in my car LOOK like they are what would be commonly called "6x9s". Can anyone confirm this? What speakers are used in the front, in the dash? This is all using the quad stereo setup AM/FM/8-Track player.


From Steve:

It does look as if 6x9's are used under the package shelf in my '75....although, my speakers are missing. I also need a front speaker since the paper on one of them has dried-up and crumpled away.

I believe the one thing to be concerned about when replacing speakers is the "ohmic-value". In order for the speaker to sound right, it must have the same ohmic-value as the ones that matched the factory radio? I'm gonna take one of my front speakers and go to Radio Shack one of these days...and see what they have. Just any ole' speaker that will fit...won't sound right.

From Matthew:

74-78 C body used 6x9 in the rear and 5.25 in the front. Matt ( 74 Imperial LeBaron Infinity stereo & new speakers, 75 Imperial LeBaron Original 8 track, 77 Town & Country Original 8 track, 85 Aries Quartz Lock cassette, 86 5th Ave Quartz Lock cassette.)

This page was last updated June 10, 2004. Send us your feedback, and come join the Imperial Mailing List - Online Car Club