View Full Version : 123 recone

03-30-2005, 07:25 PM
This CERTAINLY cannot replace the masterful guide that Bo wrote in July 2003, but can be used to augment it. I HIGHLY recommend reading that first. It can be found here:

Recently there was a question about refoaming and reconing brought up and I thought I would show this as it might help someone. I want to stress that I have some basic mechanical and some decent electronic skill, but prior to joining this forum a few months back had never done a resurround or recone. IMHO doing a recone with an original JBL kit is easier than a resurround as, as far as I'm concerned, there are fewer things to screw up. For example, when you do a recone there are fewer things to damage when cleaning up the gluing surfaces during preperation, as the cone, spider and voice coil are not in play. So......

I started with a JBL 123a-1 woofer. You can see that I have cleaned up the gluing surfaces at the surround edge and the spider mounting surfaces. Not surgical, but I believe sufficient.

03-30-2005, 07:31 PM
Add 1 C8R2212 recone kit. As you can see this kit is a prebuilt, meaning that the spider, voice coil, cone and surround are already assembled. This is what makes these kits so easy.

03-30-2005, 07:50 PM
In the kit there is a shim inside the cardboard cone that the recone assembly is shipped on. You'll need this in a moment. As part of the cleaning process you need to be sure there is no foriegn matter in the gap. Take a piece of masking tape and move it through the voice coil gap. This will pick up any unwanted debris in the gap that my damage the voice coil. Then take the shim and place it in the gap.
NOTE: The picture used to show the gap cleaning is really a 2213. I omitted the photo when I was doing the recone.

03-30-2005, 07:57 PM
hector i just wanted to add something i normally blow the gap out with an air gun or use a vaccum to bring up anything that might not come up with the tape. and MEK or Acetone will normally reactivate most glues and make cleanup a little easier. i have seen some peole use a sanding disk to remove the harder spots (if you've ever worked on an RCF or EV you would know about tough glue lol) Good pictures though and happy reconing

03-30-2005, 07:59 PM
You want to put glue on the spider and surround mounts indicated by the green arrows. Sorry if this one is overstating the obvious. This photo was another afterthought, and is again the 2213. The 123a has the same glue points, however the 123a-1 spider mounting surface is a bit narrower.

03-30-2005, 08:10 PM
Slide the cone over the shim and press the spider and surround down onto the glue. NOTE: The shim is inside the voice coil. In this photo it's hard to see.

03-30-2005, 08:21 PM
Next, while the glue is setting, you'll want to attach the posts to the voice coil leads.
Now comes the differances of opinion. Some people prefer to leave the shim in until the glue is completely dry. Some remove the shim and supply a 30Hz tone to the speaker to check for rubs and also to center the voice coil. I opted for removing the shim and applying a 30 Hz tone.

03-30-2005, 08:27 PM
I came back to do the dust cap, but in my absence, Fathers helpers had not only installed the dust cap, but gave the woof a sound check! (It passed). I had to pull it out of the cabinet and lay it back up here to snap the last pic.

Needless to say - test fit the dust cap on the cone. It's cut to fit with a slight lip on the edge to fit over the voice coil nicely. Apply a small bead of glue around the edge of the voice coil @ the voice coil/cone junction. Then place the dust cap over it. If you use a piece of masking tape on the dust cap to hold the dust cap while you place it, it makes it easier to position without getting a glue mess.
After it is set, carefully remove the masking tape.