Circuit City does them

 

You should be able to get new aftermarket replacements

 

Jackson Speaker Service is a name I've seen pop up frequently.

I had a friend who does a lot of car radios send to a different guy he used a lot, but I don't remember his name.


The repro speakers I've seen are not correct reproductions in several respects. If possible, I prefer to recone the originals.

 

I've used Muller Speaker 50 or so times before moving south. Top quality work. The last one I needed done was a 15" full range speaker with a field coil and was going to cost me big bucks to ship so I found someone in Knoxville where I could drop it off and pick it up when I was in the area.

The thing about replacements is that you need to know every detail of the old speaker so you can get a new one that is the same. Size matters but frequency response and other factors matter even more. I have 2 pair of old Marantz speakers, one pair when the foam surround rotted out of the woofers, the owner replaced them with some high-quality woofers. They sounded like crap since they weren't designed for the cabinet they went into. Lucky for me, he saved the old speakers and ended up giving it all to me. I need to sell one pair since I don't use them anymore.

For just the foam surround, I do them myself now.

 

Tony is right about the speakers.

Now, this is based solely on the repro speakers I took out of my '57 that were installed by a previous owner. But, the ones I took out didn't even match the impedance of the original speakers. (No, I didn't measure the actual impedance while in operation - I just used an ohm meter as a rough estimate.)

The repro '57 speakers don't have a transformer, so you can't hook up the optional rear speaker (which my car had). Instead, they just use an inductor (aka a choke - not to be confused with the choke on a carburetor) to simulate the transformer in the circuit.

All in all, I was not impressed with the repros I pulled out of my '57

 

Don't ever buy one with the fake choke transformer.

Original '57 speakers were 4 ohms impedance, You can measure the resistance as slightly under 4 ohms with a DC multimeter.
There are also date codes on the speaker magnet on original Delco speakers if you want to look.
One example: w/o transformer: 7269880 466725 (466=Delco, 7=1957, 25=25th week/June 16+) (came with my original manual tune radio)

Needing or not needing the transformer on the speaker doesn't change when you add a original accessory rear speaker.
See the rear speaker installation instructions (in the accessory manual?).

The transformer mounted on the speaker is required to isolate the output stage bias voltage from the speaker itself, and it is only needed on the original pushbutton radio that is self contained and partially transistorized (hybrid tube + transistor).
It's not needed on the pushbutton radio with the separate power supply/amplifier or the wonder bar pushbutton radio, which also has the separate unit.
It's not needed on the manual tune radio either.

My front speaker had a blown voice coil (it made a scratching sound when I pushed in and out on the cone), so I had it reconed.
I bought all of the parts needed for a rear speaker installation, but it turned out the rear speaker I bought was an 8 ohm speaker, so I had it reconed to 4 ohms as well.
I haven't assembled the car far enough to install the radio or speakers yet.
I bought the rear speaker and had both reconed by the same ebay seller.
He's still active. PM me for the seller's ebay user name. He has 1500+ transactions and 99% positive reviews.

 

Just to clarify the above comments:

All trifive radios - including the '57 manual tune and Wonderbar - use a transformer to couple the final stage of the amplifier to the speaker. Only the '57 pushbutton with a transistor as the final stage amplifier has the transformer mounted on the speaker.

The others all have the transformer mounted on the power supply (which also contains the final amplifier stage). Note the vertical dashed line on the Wonderbar schematic below - everything to the right is part of the power supply.

'57 pushbutton with transistor output:

https://chevy.oldcarmanualproject.com/radios/pdf/6D864dep.pdf

Other '57s:

https://chevy.oldcarmanualproject.com/radios/pdf/6D-863dep.pdf

https://chevy.oldcarmanualproject.com/radios/pdf/6D865dep.pdf

There is also a '57 pushbutton with the separate power supply and a tube output stage. That web site doesn't have the schematic, but it's basically a '56 radio in a '57 box. It's 987693 as seen in https://chevy.oldcarmanualproject.com/radios/pdf/6D800gmd.pdf

The transformer is key to installing the rear speaker, and can be done with all radios:

1957 Chevrolet Passenger Car and Truck Accessories Installation Reference Manual

 

Wow! You guys are a wealth of information. I do have a rear speaker. One of the speakers is a Delco and another is a Zenith, Delco in the front. I had sent them to Mueller and he is unable to get parts. He seemed really knowledgeable and called me on a Sunday to discuss. Real nice guy. He pointed me to partsexpress.com for new 4 ohm speakers.

 

Wow! You guys are a wealth of information.

Well, I have occasionally referred to myself as "an overflowing fountain of useless information".