)I started out with my beloved, but wrecked JBL D-130F, with a seized voice coil.
I did a bit of web searching and came across a company called Sound Speaker Repair, who did a recone kit claiming to be as close to original as possible (JBL no longer make the parts to properly recone a D-130.) Their kits also already have the voice coil, spider and cone assembly, er, assembled, which was a selling point to me, as affixing these parts together needs to be pretty much spot on to end up with a working speaker.
To start with, I cut through the old cone next to the surround with a stanley knife all the way around, and then did the same through the spider (the spider is the orange bit I'm cutting through here).
Clipped the voice coil leads, and then lifted out the whole assembly:
The cork gaskets were next, I used a screwdriver to lever them off the frame. In hindsight I probably should've used a blade underneath them to cut them away from the frame - there was a lot of glue left to clean off. (Copper tape covering the voice coil gap was due to me running out of masking tape before I started taking photos.)
Here you can see the voice coil gap, which has been covered with masking tape. Debris getting in the gap = a very bad thing. The remnants of the spider, and the 40 year old glue holding it down to the mounting surface were stuck very well. I slid a razor blade tool underneath to help lift it up:
Quite a long time later, I'd finished cleaning the frame. Lots of elbow grease, hobby blades, a kitchen scourer, and a 'goo remover' product made of xylene. PS - Don't wash your hands with xylene, it BURNS. I've dealt with lots of cleaners/chemicals on my skin, but xylene definitely caused the worst reaction. Acetone probably would've been a better assistant for this for that reason alone. I suspect it may 'deal' with speaker adhesives better too.
Next is to clean the voice coil gap of any debris that might be in there. I'm using masking tape, and just wiping it around the gap using the adhesive to attract any dust/dirt. LOTS. I covered the voice coil with masking tape again then went to bed. When I started working on this again the next day, I cleaned the voice coil gap again just to be doubly sure there was nothing in there.
Next step is to test-fit the assembly to make sure everything's looking OK. Here you can see the thick paper shims (provided in the kit) to centre the voice-coil in the gap.
Now the moment/s which caused me some nervousness. Applying a bead of adhesive to both the basket and spider mounting surfaces before dropping the whole assembly into place.
Note the shims are still in place - the voice coil will be lowered around these and be held centred in the correct position when you drop the assembly in position, like so
No photos of the next step. The spider and the edges of the surround needed to be pressed down on their mounting surfaces to ensure a good bond. After this I glued the cork gasket pieces (4) in place. After this your hands will probably look something like this - the adhesive spreads very well.
Once the cork gaskets were seated in place, and I was certain the edge of the spider was pressed fully down and bonding to its mounting point, I turned the speaker over and sat it face down on the gaskets so the weight of the speaker could help bond the gaskets (and the edge of speaker surround which is sandwiched between the gasket and the frame) to the frame.
About 9 hours later I glued the dustcap in place. No picture of this. As simple as it sounds - place the dustcap where it'll be mounted to the cone, trace around it with a pencil, run a bead of adhesive along the traced line and then press the dustcap into the adhesive. I followed the SSR instructions and used an upside down shot glass to apply pressure to the dustcap, then went to bed.
So, almost done. Just need to solder the voice coil leads to the speaker terminals, ensuring there's enough spare lead to allow for cone movement up/down without shorting out against the frame:
Done, soldered and trimmed the excess. Quick check with the meter to make sure everything's still looking as it should (also worth checking before you start to make sure you've been sent the right ohmage kit).
Back in its rightful place, after several weeks out of action:
The mounting screws were done up just tight enough to know the speaker was affixed to the baffle (roughly approximating finger tight). Here's a quote from Harvey Gerst, who created the D130F during his time at JBL, with the reason why:
EDIT: A quick photo comparison:Opened the voice coil gap slightly on the D130F to allow more tolerance in
mounting. Most people didn't realize that even though 8 mounting holes were
available, only using four is the recomended mounting. And you don't screw them
down tight to the board - that warps the frame. You use two fingers to do the
final tightening - the casket will them complete the seal. When you warp the
frame by overtightening, the voice coil can go out of round and eventually drag
and short out. I opened the gap slightly to allow for this problem with just a
very slight loss in efficiency - less than 1 dB.
Old spider and voice coil assembly after removal:
And the new:
My initial impressions of the newly reconed speaker are very favourable. I'm yet to use it in a band setting (Tuesday) but I plugged my G&L ASAT in and played at 'band volume' for a little while this afternoon, and it sounded absolutely beautiful - I've really, really, really missed the sound of the JBL paired up with my amp.
Cheers, I hope this may have been of use to anyone tossing up whether or not they'd like to do their own recones, but unsure of the process. I'll post back after Tuesday's rehearsal once it's had 4 hours of decent volume pumped through it in it's 'usual' context.
), which could just as likely be the reason.
