4311 resurrection

[Goldjazz]

My first attempt at bringing a pair of speakers back to life. A pair of 4311A's.

I got my hands on these several months ago. They actually sound pretty good to me. Though the tweeters are not in the best shape. I recently used these guys at a nye party everyone was blown away by the power and detail of them, damn fine rock speakers IMO.

I intent to strip back the cabinets and restore the original Studio grey finish, recap and possibly replace the LE25's.

I know there's plenty of 4311 restoration posts (I've checked out a few of them) I'm starting this one partly to get any advice as I go, partly to give me motivation to get it done, and because I thought some of you may find it interesting.

The LE5-2's are in good nick and sound great, they are both measuring 6 ohms.
The 2213's are also pretty good, reading 4.8 and 5.2 ohms.
The LE25's are not great. the paper cones appear a bit creased and the sound of the upper range is a little lacking. Replace em? they are reading 4.5 and 5 ohms.
So all these readings are well below the 8ohms, is this unusual?

So I've got the 3112 crossovers. I notice one is painted black (No. 77581A) with the Caps marked "mexico" while the other is not black (No. 86318A) The pots also appear to have different numbers. One of the crossovers changed at one point? I'm gonna do the recap with the 2x4mF daytons, 1x3mF Dayton, and the 0.01mF Theta.

As for the cabinets I started applying paint stripper and the layers of old paint scrap off pretty easily.

As I said, I'm an absolute novice so any advice appreciated.

[Goldjazz]

...and more pics

[Goldjazz]

...couple more pics

[ratitifb]

amazing resurrection!

and very nice match with the original JBL grey paint

By the way what paint reference and/or formalution have you used ?

[Goldjazz]

amazing resurrection!

and very nice match with the original JBL grey paint

By the way what paint reference and/or formalution have you used ?

Thanks! So I took the cabinets to a place to have the colour matched, the sides and tops had been painted over many times but the front and backs were unaltered. So hey were able to take a reading and get a pretty close match. So the custom mixture has some info printed on the label which i guess would allow it to be mixed up again easily. If you like I can take a pic of that and share it.

[Greg86z28]

Nice Job!

[tinpan]

Wow, these are very nice. Excellent thread

[Goldjazz]

Wow, these are very nice. Excellent thread

Cheers, was a good little project. Doing some L166's now.

[ratitifb]

The LE5-2's are in good nick and sound great, they are both measuring 6 ohms.

The 2213's are also pretty good, reading 4.8 and 5.2 ohms.

The LE25's are not great. the paper cones appear a bit creased and the sound of the upper range is a little lacking. Replace em? they are reading 4.5 and 5 ohms.



So all these readings are well below the 8ohms, is this unusual?

all values seems OK regarding the DC resistance of the different coils except for the LE25 a little bit high (but probably OK...).
8 ohms is the "standard" impedance including the DC resistance plus the coil impedance and the other parts of impedance (mecanic, acoustic, ...)

A lot of restoration work to be done by the way

Please let us know with pictures

Courrage

[Greg86z28]

Looks great.

These threads are awesome, I always feel I have more fun (and do a better job) when I'm sharing my experience with other people!

[Goldjazz]

thanks for the DC resistance info ratitifb, and the encouragement greg. Will keep the pics coming. Here's what the LE25s look like, that resistance result and the fact that the cones are a bit crumpled (not just dust caps) leads me to think I should replace them.

[Goldjazz]

Update: so ive replaced the capacitors in one crossover. Havent fired it up yet. Pics to come. The old caps were reading 8.4 uF and 3.3 uF for the 8 and 3 respectevly. While the new ones are pretty much bang on spec.

While ive got them open just wondering if there's anything else I could/should do. E.g. replace internal wiring with better stuff, replace speaker terminals. Ive heard of folks remagnetizing drivers is that just bs? And where would anyone get such a thing done.

Also scrap my previous comment about the paint coming of easily with painy stripper and a scraper....its a bugger of a job and im not even half way through it.

Anyone know jow to achieve the textured finish of the studio Grey?

I think i may have also sourced a new pair of Le25s hopefully.

[Goldjazz]

The paint strips back to the raw, clean particle board, but man is it hard work. I think on all side except front and back, these speakers were repainted twice.

[Goldjazz]

Ok so I've completely stripped back one cabinet. I'm going to totally finish one cabinet before starting on the other so I can match the original paint and finish.

Next step is to spray putty, light sand and spray primer, then paint. There's some info on this forum re a spec of the original grey colour. I will try to get that, or get a colour match on the other cabinet. The sides of both cabs were painted over several times, the front and back were not so I've got that as a reference. I'll need to experiment with a spray gun to get the texture right.

I've also installed the new caps onto on x over, but not hooked it up yet. Doesn't look very neat I must admit but should do the job. The white stuff is sikaflex, a silicone glue which is somewhat shock proof. I didnt want to expose the caps to heat of hotmelt. BTW These caps and the silicone glue were speced on a forum over at Audiokarma by a member called Brainwashed. Next step will be to hook them up and test the drivers.

Mint, reconed LE25s will be travelling from the other side of the planet soon, thanks member S.O.Stefansson!

[Goldjazz]

So progressing well on the first cabinet. I've done two coats of spray putty and sanded each with 180 grit. I also sharpened up the corners with automotive putty and sanded.

I got the Studio Grey paint matched, seems pretty close. I also got a spray gun and did some trials. Seems the closest texture results from a couple of coats at a very fine spray setting, followed by a final coat with the paint volume turned right up on the spray gun and firing at a bit of a distance. This produces the large textured blotches. You can't be too heavy handed with this final coat or the blotches lose their definition.

The yellow finish below is the spray putty/primer coat. This is an automotive sandable stuff from a spray can. it sands nicely.

The grey finish is the first fine coat. It's still wet so appears a bit patchy and light. Should get a bit darker when it dries. As I said, I'll be applying another fine coat and then the final textured coat. Also attached is the original finish on the other cabinet.

I'll be sourcing some good hook up wire and solder and replace all the wiring and solder joints. I'm thinking of upping the wire gauge in all cases and probably getting this very pure copy neotech hook up wire, and some silver solder.