Rear Speakers

[Gregg Benedict]

Has anyone installed rear speakers in a '57-'59 Imperial? I assume the openings in the rear deck behind the seats are made to accept 6x9's, but not sure. It looks like I may have to do some cutting on the cover to be able to hear the speakers as well.

 

[58Belvedere]

5x7 Exact fit 5'' x 7'' speaker for 1957-59 Chrysler Corp. passenger cars

 

[58Belvedere]

https://www.amazon.com/Rebower-Spea...cphy=9023573&hvtargid=pla-2281435177138&psc=1

 

[Gregg Benedict]

5x7 Exact fit 5'' x 7'' speaker for 1957-59 Chrysler Corp. passenger cars

This is for the front speaker, yes? I'm talking about the rear speakers.

 

[CBODY67]

Remember that back then, only ONE rear speaker was normal. No factory stereo radios, so no need for two speakers back there. There might be an air intake hole which can coincide with the speaker size, that was for a possible rear heater/defroster option?

CBODY67

 

[70NEWYORKER]

Back in the early Eighties I mounted two 6x9's in the package shelf of my 1959 Savoy with NO cutting or drilling. Mounted from underneath like it was designed for it. Print this template at the following link or find your own and see how it looks.

https://images.carid.com/mtx-audio/items/pdf/thunder693-drilling-templates.pdf

 

[UGW]

Here's my experience with my '63. I don't know if it will be the same, but they do share a lot of parts once you get past the skin.

- My '63 had what I believe to be a factory-installed rear speaker. It doesn't have a lot of markings, but it looks just like some pictures I've found of NOS Mopar rear speaker kits from the period. The trim tag also confirms it should have been installed. (Thanks, Torky!)
- It was definitely 6x9
- The speaker mounted to the underside of the rear shelf, from the trunk, with simple sheet screws
- If you line up carefully, there are already holes you can use for the screws, no drilling!
- There is an identical 6x9 hole on the passenger side - cars with a rear defroster use this as an air intake for the blower. If you look up a Mopar rear defroster from this time, you'll see it is also, obviously a 6x9 shape
- My rear shelf panel disintegrated when I removed it, but it had perforations on both sides to match the holes in the body

- Are you using the factory radio, or something modern? This will have a lot of impact on sound clarity and speaker choices
- The speaker was 4 Ohms when tested with a multimeter. Some people claim old speakers are higher resistance, but both the electrical diagrams in the FSM, and markings on some NOS rear speakers I've found support the 4 Ohm rating
- The factory radio only expects 4 ohms on that rear circuit, so if you want to run two speakers with the factory radio, you need either run two 8 Ohm speakers in parallel, or two 2 Ohm speakers in series. (How to Wire Speakers in Parallel & Series, and how does it affect Impedance?) However, there's not really a point to this complication, since the sound will still be mono. You might as well just run one speaker in the stock location
- Keep in mind, the factory radio is anemic by modern standards. Maybe 10W per speaker? So you don't need massive 100W RMS speakers.
- With factory radio, the radio is your limit on sound quality. It's designed for mono, AM radio, so even the best speakers with a clear hole cut in the shelf won't make much difference
- If you're installing an aftermarket radio, all bets are off. You can do whatever you want.
- Depending on your speakers, you may need to use a small spacer/gasket (which may come with the speakers) to keep the cone from bottoming out on the body, which will sound bad

Here's a picture of a '61 or '62 (not mine) with a speaker and rear defroster installed.

 

[CBODY67]

As a point of reference, our '66 Newport came with a factory rr speaker and related fader. A part of a popular option package. I liked the sound quality compared to similar Ford (a bit flat) or GM (upper frequency response limited) radios.

Several years later, I got a factory Chrysler rear speaker accy package from the local dealer. I matched the color codes on the wires and put them to the new rear speaker. Worked great! The factory radio (being a Chrysler, I suspect it had the more power amp than a similar Plymouth radio would) had enough guts to play rock music loud enough that if anybody was in the rear seat, they'd have to hang onto the back of the front seat to get away from it. LOL Enough guts to play "Smoke on the Water" at 70mph, driver's window down, plenty loud, too.

Frequency response for a car speaker was impressive. I had a stereo test record for frequency response and they'd go to about 10K Hz before tapering off. So, plenty good for classical and pop music of the middle 1960s.

As to modern speakers, most quote high amp ratings with big magnets on them. Those big magnets seem to be "watts hogs" which might take more power than the stock radios have to run them well. So, with a stock radio, small or moderately-large magnets can work best. Most will be 4ohm rated speakers. HOPEFULLY, the speakers will have some sort of grille cloth over them to keep debris from settling onto the speaker cone! I suspect the most basic dual-cone speaker will sound just fine with the stock radio or thereabouts, as things have evolved over the years. The "first upgrade" used to be the Jensen 6x9 dual cones with a moderate-sized magnet on them, for example.

On the '66 and '70 Monaco, under the rear package tray was a layer of jute sound insulation . . . with perforations to help cut it out with. A somewhat dirty job, as to dust within the jute.

Just some thoughts and my experiences,
CBODY67

 

[JimmyG]

"Smoke on the Water" at 70mph. You radical you! Love it!

 

[fury fan]

As to modern speakers, most quote high amp ratings with big magnets on them. Those big magnets seem to be "watts hogs" which might take more power than the stock radios have to run them well. So, with a stock radio, small or moderately-large magnets can work best. Most will be 4ohm rated speakers. HOPEFULLY, the speakers will have some sort of grille cloth over them to keep debris from settling onto the speaker cone! I suspect the most basic dual-cone speaker will sound just fine with the stock radio or thereabouts, as things have evolved over the years. The "first upgrade" used to be the Jensen 6x9 dual cones with a moderate-sized magnet on them, for example.

Magnet size is related to the speaker's wattage capacity, but a speaker will not take beyond what the radio can supply. (unless you use a speaker whose impedance is too low, then it can overload the radio's output bits) Sensitivity is the critical spec in an application like this.

#1 and #2 important specs, if adding modern speakers to a vintage radio:
Do not use a speaker with impedance LOWER than the original.

#2, if the radio has low output wattage - find a speaker with the highest sensitivity you can find. This is usually rated as xx dB @ 1 watt / 1 meter, or sometimes as 2.83 volts @ some standard distance. This is critically important to how much volume the radio/speaker can make, esp as most OEM radios from back in the day are <5 watts. Even a few dB increase on the speaker sensitivity makes a noticeable increase in overall volume. One cannot simply compensate for that by turning the radio volume up, as wattage/sound decibels are not linear, and with a 5-ish watt radio, you don't have much horsepower to make a low-sensitivity speaker play loud.

Now with that said, you are still limited by the sound quality of the radio's output signal.
My recommendation for a factory radio is to pair it with a 2-way speaker with a textile-dome tweeter.
Try to find 89+ on the sensitivity.
Something in the range of $75-100 should give sufficient quality.

 

[CBODY67]

Unlike home audio, car radio amps never were rated for "levels of harmonic distortion" at peak power. Which means their rated output is probably optimistic for getting clean signals from the amp itself.

As cars have become quieter, the quality of the sound output has become more critical, usually better. But as interior width dimensions have decreased, with infinitely more sound-absorptive surfaces, not nearly the same sound environment of a 1970 New Yorker, for example.

Personally, I like "Channel A - Channel B" stereo sound. Hearing the sound spread and fill the entire interior. Only thing is the seating position to hear these things is not optimum for such. To me, Chrysler's use of upward-facing stereo speakers, combined with the existing center speaker, made for one great sound experience. A well-balanced sound imaged off of the windshield. Backed-up by the two rear speakers upward-facing to the rear window. Using the glass contours to reflect the sound all through the interior, in the process. With, of course, better speaker frequency response (remember that term???) than either Ford or GM speakers had. Well before the days of "boombox sound".

CBODY67