I am restoring a Stromberg Carlosn model 84 console with the Labyrinth speaker system.
The problem is, the voice coil on the speaker is open.I
need to know what the impedance of the voice coil is, this speaker has the light pliable leather surround material. Speaker cone is in excellent shape and the
electro magnet on back is in good shape.
Many thanks for any replys --------- John A Bellas.

The reason why your speaker coil is open is because it is made of aluminum. Aluminum is not solderable, and so the wires must be crimped. DO NOT REPLACE THIS COIL!!!!!!!!!!!!!!!!!! The reason for aluminum is because it is lighter and responds better to the higher frequencies (FM, etc.). Regular copper voice coils fall off where this coil will continue to respond. Aluminum is SOOOOOOOOO much better at responding to the high frequencies. Your speaker is a real high end speaker.

All you have to do is remove the cone and find the break in the coil. Then crimp it back together. It is probably broken right where it joins at the crimp. Open the crimp, remove one turn of wire, and recrimp. One turn won't make much difference. Be careful and thoughtful and thorough. Don't damage anything. Think it through!

Those radios are fabulous! They have motorized tuning (some of them). They have superb sound. The speaker cone is made of a very stiff material, which is how a proper speaker cone should be. The surround is leather. Modern speakers of good quality use a poly or aluminum cone for rigidity and good high frequency response, and use a foam rubber surround for the bass response. The nice thing about the leather is that it lasts MUCH longer. The foam from 1970 will be fallen off by now, but the leather from 1940 will still be holding together. Perhaps oil it lightly to maintain its flexibility.

I forgot whether the cones on the labrynths are glued into place or screwed into place (with a ring and screws). If it is obvious that the cone is glued in place (around the outside), then you must soak the edge with acetone, which will soften the glue. The center, which usually uses a center mounted spider with screw in the middle, is simply unscrewed with the center screw. Unsolder the leads from the terminals. When reassembling, make three long and narrow (not more than a quarter inch in width) strips out of index card material. Use these three strips evenly spaced around the pole piece to center the cone before tightening the center screw (cone must be in place....insert shims...tighten screw). Once center screw is tightened, check for rubbing. As for attaching the outside of the cone, which should be done before the center is tightened, you can soften the glue again with acetone, or use Elmer's white glue. Elmer's is strong and will do well. While the glue is still soft, align the center of the cone as mentioned above, and tighten the set screw. This will bring everything into alignment. Allow to stand with cone facing up, so that glue can dry.

Any questions, ask me. Don't do anything that will ruin your speaker! Be slow and through. If you need to, send me pictures. You will be able to repair it and you will enjoy the results.

Thomas

:The reason why your speaker coil is open is because it is made of aluminum. Aluminum is not solderable, and so the wires must be crimped. DO NOT REPLACE THIS COIL!!!!!!!!!!!!!!!!!! The reason for aluminum is because it is lighter and responds better to the higher frequencies (FM, etc.). Regular copper voice coils fall off where this coil will continue to respond. Aluminum is SOOOOOOOOO much better at responding to the high frequencies. Your speaker is a real high end speaker.
:
:All you have to do is remove the cone and find the break in the coil. Then crimp it back together. It is probably broken right where it joins at the crimp. Open the crimp, remove one turn of wire, and recrimp. One turn won't make much difference. Be careful and thoughtful and thorough. Don't damage anything. Think it through!
:
:Those radios are fabulous! They have motorized tuning (some of them). They have superb sound. The speaker cone is made of a very stiff material, which is how a proper speaker cone should be. The surround is leather. Modern speakers of good quality use a poly or aluminum cone for rigidity and good high frequency response, and use a foam rubber surround for the bass response. The nice thing about the leather is that it lasts MUCH longer. The foam from 1970 will be fallen off by now, but the leather from 1940 will still be holding together. Perhaps oil it lightly to maintain its flexibility.
:
:I forgot whether the cones on the labrynths are glued into place or screwed into place (with a ring and screws). If it is obvious that the cone is glued in place (around the outside), then you must soak the edge with acetone, which will soften the glue. The center, which usually uses a center mounted spider with screw in the middle, is simply unscrewed with the center screw. Unsolder the leads from the terminals. When reassembling, make three long and narrow (not more than a quarter inch in width) strips out of index card material. Use these three strips evenly spaced around the pole piece to center the cone before tightening the center screw (cone must be in place....insert shims...tighten screw). Once center screw is tightened, check for rubbing. As for attaching the outside of the cone, which should be done before the center is tightened, you can soften the glue again with acetone, or use Elmer's white glue. Elmer's is strong and will do well. While the glue is still soft, align the center of the cone as mentioned above, and tighten the set screw. This will bring everything into alignment. Allow to stand with cone facing up, so that glue can dry.
:
:Any questions, ask me. Don't do anything that will ruin your speaker! Be slow and through. If you need to, send me pictures. You will be able to repair it and you will enjoy the results.
:
:Thomas

::The reason why your speaker coil is open is because it is made of aluminum. Aluminum is not solderable, and so the wires must be crimped. DO NOT REPLACE THIS COIL!!!!!!!!!!!!!!!!!! The reason for aluminum is because it is lighter and responds better to the higher frequencies (FM, etc.). Regular copper voice coils fall off where this coil will continue to respond. Aluminum is SOOOOOOOOO much better at responding to the high frequencies. Your speaker is a real high end speaker.
::
::All you have to do is remove the cone and find the break in the coil. Then crimp it back together. It is probably broken right where it joins at the crimp. Open the crimp, remove one turn of wire, and recrimp. One turn won't make much difference. Be careful and thoughtful and thorough. Don't damage anything. Think it through!
::
::Those radios are fabulous! They have motorized tuning (some of them). They have superb sound. The speaker cone is made of a very stiff material, which is how a proper speaker cone should be. The surround is leather. Modern speakers of good quality use a poly or aluminum cone for rigidity and good high frequency response, and use a foam rubber surround for the bass response. The nice thing about the leather is that it lasts MUCH longer. The foam from 1970 will be fallen off by now, but the leather from 1940 will still be holding together. Perhaps oil it lightly to maintain its flexibility.
::
::I forgot whether the cones on the labrynths are glued into place or screwed into place (with a ring and screws). If it is obvious that the cone is glued in place (around the outside), then you must soak the edge with acetone, which will soften the glue. The center, which usually uses a center mounted spider with screw in the middle, is simply unscrewed with the center screw. Unsolder the leads from the terminals. When reassembling, make three long and narrow (not more than a quarter inch in width) strips out of index card material. Use these three strips evenly spaced around the pole piece to center the cone before tightening the center screw (cone must be in place....insert shims...tighten screw). Once center screw is tightened, check for rubbing. As for attaching the outside of the cone, which should be done before the center is tightened, you can soften the glue again with acetone, or use Elmer's white glue. Elmer's is strong and will do well. While the glue is still soft, align the center of the cone as mentioned above, and tighten the set screw. This will bring everything into alignment. Allow to stand with cone facing up, so that glue can dry.
::
::Any questions, ask me. Don't do anything that will ruin your speaker! Be slow and through. If you need to, send me pictures. You will be able to repair it and you will enjoy the results.
::
::Thomas

I forgot to mention that the center spider of the coil section was found to be broken out on this speaker probably causing the open, but carefull inspection of the coil I could not find any obvious rubbing type of wear on coil itself. When you are talking about the Crimp connections I am assuming you are talking about the ones where the outside wire comes off of the cone area before it travels to the terminal strip?? Will the acetone loosen up this black colored glue? ------------------- Many thanks so far ------- John A Bellas.

If your speaker is like the Stromberg Carlson labrynth speakers I've seen, the central spider is mounted where the dust cap goes on modern speakers. It is a perforated affair made of cardboard or some other strong, fiberous material. The total unit is perhaps an inch to an inch and a half in diameter. It glues to the cone on its circumfrence, and in the center, a screw fastens it to a post that extends up from the center pole piece. If this spider is disconnected from the cone, simply glue it back in place (around the outside of the spider). If it is broken, try to repair it--try gluing the broken parts back together, or if its broken beyond repair or is missing, you will have to substitute a modern outside spider for the original, as the original is not obtainable.

As for rubbing, your speaker does not have to rub to blow the voice coil. Someone could have turned the set up too far and overheated the coil, or the coil could have simply oxidized at the crimp. It is aluminum. The way it is fastened is the leads that come from the terminal strip are fastened to the paper cone. They run right up against the circular form which the voice coil is wound on. At the end of each lead is a small metal piece that is crimped to each lead. The ends of the fine aluminum voice coil are also crimped to these pieces of metal. If the voice coil is broken at a crimp, or fails to make contact with the crimp (test with multi-meter by seeing if you can get continuity from the wire right before the crimp--scrap away a bit of insulation), then this crimp must be carefully opened with a razor blade, and then the wire is reinserted, and the metal is crimped back down over the wire.

The black glue that holds the outside of the cone to the frame can be loosened with acetone.

If you have any questions, email me pictures. bigbadpiratetom@yahoo.com

Thomas

: I forgot to mention that the center spider of the coil section was found to be broken out on this speaker probably causing the open, but carefull inspection of the coil I could not find any obvious rubbing type of wear on coil itself. When you are talking about the Crimp connections I am assuming you are talking about the ones where the outside wire comes off of the cone area before it travels to the terminal strip?? Will the acetone loosen up this black colored glue? ------------------- Many thanks so far ------- John A Bellas.
:

Thomas:
many thanks for the pointers that you have given to me. I will be looking at the speaker and try to determine if the crimp connections are bad. My next step is to get some acetone or nail polish remover to clean up the connections and re evaluate them and if need be , re do the crimp connections. I hope you had a GOOD Thanksgiving! and I hope that you will have a very MERRY CHRISTMAS coming up. I will likely be able to get back on the speaker for the Stromberg Carlson in a few days to a week or so. As far as the chassis is concerned I basicly done a whole recap all the way around and had to replace most of the resistors . I substituted another whole speaker for the time being using just the voice coil connections and left the electromagnet hooked up on the old speaker for trial run and the chassis works well now. So the original speaker is my next project. Once again many thanks so far for the help. I will make another entry here as I go further to keep you informed.

Good luck! You could replace the speaker with a new one and leave the field in place for the resistance. The only trouble is that 10 inch speakers are not usually produced to-day with aluminum voice coils, as they are not often required to-day to respond to the whole human hearing range. They usually are only designed to respond to the bass region. If you were to replace the original speaker, you'd have to use a combination unit that utilizes both a 10 inch speaker and a small tweeter wired through a cross-over network. Hopefully you can get the original speaker working properly.

Thomas

:Thomas:
:many thanks for the pointers that you have given to me. I will be looking at the speaker and try to determine if the crimp connections are bad. My next step is to get some acetone or nail polish remover to clean up the connections and re evaluate them and if need be , re do the crimp connections. I hope you had a GOOD Thanksgiving! and I hope that you will have a very MERRY CHRISTMAS coming up. I will likely be able to get back on the speaker for the Stromberg Carlson in a few days to a week or so. As far as the chassis is concerned I basicly done a whole recap all the way around and had to replace most of the resistors . I substituted another whole speaker for the time being using just the voice coil connections and left the electromagnet hooked up on the old speaker for trial run and the chassis works well now. So the original speaker is my next project. Once again many thanks so far for the help. I will make another entry here as I go further to keep you informed.