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

[ratitifb]

The LE5-2's are in good nick and sound great, they are both measuring 6 ohms.
61360
The 2213's are also pretty good, reading 4.8 and 5.2 ohms.
61361
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.
61362


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

Please let us know with pictures :bouncy:

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.

[macaroonie]

Good job. :applaud:

Don't waste your money on Monster cable for the hook up , it corrodes anyway. ( google this )

I would lash out on a good set of terminals or alternatively use a Speakon type connector. Pretty much all of the JBL pro PA and high power stuff uses this connector.

M

[Goldjazz]

Thanks maca. Interesting point re the corrosion of hook up wire. If anyone knows of good stuff not susceptible to corrosion please let me know.

Yeah will be sourcing some nice terminals for sure, and those Speakons look sweet too.

On another thing, my foilcals have got a bit of paint on them and some of the black is worn off. Anyone successfully restored foilcals? Or know where I can get replacements?


Good job. :applaud:

Don't waste your money on Monster cable for the hook up , it corrodes anyway. ( google this )

I would lash out on a good set of terminals or alternatively use a Speakon type connector. Pretty much all of the JBL pro PA and high power stuff uses this connector.

M

[ratitifb]

hi Goldjazz

nice resurrection job !

You can contact the ebay member sign--shop ;)


http://www.ebay.com/itm/JBL-4310-4311-4312-front-Label-Foilcal-for-Monitor-NEW-/250861164944?pt=Vintage_Electronics_R2&hash=item3a687d9990#ht_338wt_923 (http://www.ebay.com/itm/JBL-4310-4311-4312-front-Label-Foilcal-for-Monitor-NEW-/250861164944?pt=Vintage_Electronics_R2&hash=item3a687d9990#ht_338wt_923)

[Odd]

You can buy new here (http://www.ebay.com/itm/JBL-L100-L200B-L300-L65-crossover-Foilcal-Labels-New-/250665659905). It is good quality.

[Greg86z28]

Looking good! I'm excited to see the final product!

[Goldjazz]

Great thanks for the foilcal info everyone. Will get these and let you know how they go!

[Goldjazz]

Well they're all done! I'm happy with the result. The recap has really made a difference in my opinion, cleaner and more detailed sound. I'm sure also the fresh le25's help (thanks again S.O.Stefansson) and thanks for everyone who gave advice.

The toughest part of the job was stripping back the cabinets, made worse by the fact that they had been repainted (badly) several times in their life. Next was achieving the paint texture, so I colour matched the original paint and got a spray gun. They gun was pretty cheapo, so i had to experiment to get the texture close to the original. It has a detachable nozzle, if you removed it the splatter was too big and messy or the splatters were round and pimply, with the nozzle on it was too fine. In the end I had to jam a screw into one of the two air jet holes of the nozzle which is off to the side of the paint outlet so the paint would hit the screw and disperse a bit. Anyway I'd probably invest in a better paint gun next time :). Also I'd try to track down a harder wearing type of paint next time.

One thing I didn't do which I will do soon is apply some fresh speaker caulking to the cabinets, particularly under the woofers. Anyone was has removed a wooofer from one of these cabinets that has never been removed will know the joy of this process. The things get stuck in there, the old caulking seems to bond to the paint and you need to place a padded surface down and drop the speaker onto it to shock the bugger out of place. tough to do without damaging anything. So you're left with a non perfect flat seat on the cabinet where bits of chip board and paint have come off with the speaker, and the old caulking is no longer compliant.

Wiring up the crossover and doing the recap was ok. I used silver loaded solder for all the joints, this was a pain to work with. I had to have the soldering iron up very hotand managed to touch one of the new caps in the process and destroy it, this set me back a week or so as i needed to order a new one. Next time I'll order more caps than I need, caps are cheap shipping to Australia from US is not! Also I used thick copper speaker wire for the hook ups, don'd do this. The stuff is just too thick to bend around and get in there. One of the points on the crossover has lots of wires coming together and its a bit of a mess, I think next time I'd get a little row of screw terminals or something and do it neater. Also the mounting of the caps on the original board is not fun, I tried double sided table and cable ties, as well as silicone goop. Also I tried to think of a better way of mounting the crossover so I wouldn't need to detach the foilcal again if I wanted to experiment with different caps in the future, In the end I didn't change it. I guess you could drill out the threads on the board, epoxy the screws in place and use wing nuts from the inside or something. Anyway I'd really recommend the recap that I've done to any 4311 owners.

The fresh foilcal was pretty true to the original. If I'm being extremely pedantic I'd say the colour of the jbl logo was a little off compared to the original and the text a little pixelated if you're looking very very closely. But the mat black is spot on, having said all this, I would definitely buy them again. I do wonder if the foilcal will be able to be levered off without damage in the future with the 3m double-sided tape provided.

For the Binding posts I used decent quality, large silver plated ones, which have worked out pretty well. I think i may have mounted the red and black in the wrong position in the cabinet, but they are correctly wired up and consistent for both cabinets.

I opted not to restore the grills. I may just buy some new grills in the future. But I wouldn't use them anyway and I prefer the look without the velcro tabs attached when the grills are off.

I also built some mass loaded speaker stands. They are 16mm thick mdf boards with spikes, and are filled with sand. This also makes a big difference in my opinion, particularly with bass response. I've opted to go a little tall with them (stands are 56cm/22 inches tall including spikes). If you've got you're 4311s sitting on a pile of books or something, you should get some solid stands made up or buy em :)

That's my Sansui au10000 integrated amp driving them which is a nice combo I think.

Anyway enjoy the pics, if anyone else is going to do a restoration like this feel free to ask me for advice.

[Goldjazz]

...couple more pics

[ratitifb]

:applaud: amazing resurrection!

and very nice match with the original JBL grey paint :spchless:

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

[Goldjazz]

:applaud: amazing resurrection!

and very nice match with the original JBL grey paint :spchless:

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!

[wpod]

I still think that the 4310 and 4311 look much more "dignified" in their grey attire. If you really want to put the icing on the cake, try one of the "improved" L100 style crossover upgrades , the one with resistors and inductors (besides the caps). In my own experience, I think the new crossovers bring the monitors to a level of performance that they truly deserve. If you want to try it on the cheap, pick up a pair of L110, L-50, or 4313b crossovers on eBay (less than $75.00) and give it a listen. Either way, enjoy those monitors, they look super! Paul

[Goldjazz]

I still think that the 4310 and 4311 look much more "dignified" in their grey attire. If you really want to put the icing on the cake, try one of the "improved" L100 style crossover upgrades , the one with resistors and inductors (besides the caps). In my own experience, I think the new crossovers bring the monitors to a level of performance that they truly deserve. If you want to try it on the cheap, pick up a pair of L110, L-50, or 4313b crossovers on eBay (less than $75.00) and give it a listen. Either way, enjoy those monitors, they look super! Paul

Thanks. Yeah I like the grey too. Something awesome happens when you've finished those clean greay boxes and you load the drivers in and put on the foilcal it just all comes together all of a sudden...very cool. Yeah I once had a pair of L110's but dont have em anymore, will think about that cheers.

[S.O.Stefansson]

Goldjazz,

the 4311s look superb, excellent job :applaud: I'm happy to have made a small contribution in the form of the LE-25 tweeters,

Sigurd


Thanks. Yeah I like the grey too. Something awesome happens when you've finished those clean greay boxes and you load the drivers in and put on the foilcal it just all comes together all of a sudden...very cool. Yeah I once had a pair of L110's but dont have em anymore, will think about that cheers.

[hjames]

VERY nice looking pair of speakers! Kudos, and enjoy!

[Goldjazz]

Goldjazz,

the 4311s look superb, excellent job :applaud: I'm happy to have made a small contribution in the form of the LE-25 tweeters,

Sigurd


Cheers...a big contribution the nice fresh tweeters really make it.

[audiomagnate]

What's your source??? Speakers look great BTW. Are there no coils in the crossover just like the L100? I thought the studio version had a more complex crossover.

[gsb001]

4311 is my favorite out of the original control monitor models 4311, 4311B and 4312A's.
Steve
Huntley Audio.com

[Goldjazz]

What's your source??? Speakers look great BTW. Are there no coils in the crossover just like the L100? I thought the studio version had a more complex crossover.

Thanks. Source is just digital files through a musical fidelity m1 dac into the Sansui at the moment. Yeah it's a very simple crossover actually just two caps and two Lpads.

[Goldjazz]

4311 is my favorite out of the original control monitor models 4311, 4311B and 4312A's.
Steve
Huntley Audio.com

Cool, yeah I really like the 4311 too. I haven't tried the others but I will if I get a chance. They actually don't come up that often. I'm told there is something special about the Alnico midrange on these 4311A's though I haven't heard the other versions to compare. I wanted to just restore the original cap values with fresher caps to retain the original sound.

[Goldjazz]

I know you can't tell much from videos taken through a mobile phone but here's a couple of clips of them in action:

https://www.youtube.com/watch?v=31PNUT35WLw

Yes that's the sound of rain in the background in both vids not static :)

https://www.youtube.com/watch?v=p6mdtFn_0Bc


Enjoy.

[bldozier]

Two questions

The studio grey, texture paint is a technique, of applying a finish vs, an actual textured paint?

2. How com you did not use a mouse or hand sander to remove the older few coats of finish.
Brian d

[Goldjazz]

Yeah it's a technique. I experimented with a paint gun to get the effect, jamming a screw in the spray jet path to disperse it into the right kind of splatter. I had the original finish left on the back as a guide. I just used normal household oil based paint that I got colour matched. I would recommend a clear coat of some sort to protect it.

Mine had several layers of paint applied with a brush messily (by the previous owner). I wantwd to get back to bare particle board so I could prime the surface properly. The paint stripping was a big job to get it all off. Prob best to paint strip once and scrape of majority and sand the rest. You might be fine to just sand yours, could be easier.


Two questions

The studio grey, texture paint is a technique, of applying a finish vs, an actual textured paint?

2. How com you did not use a mouse or hand sander to remove the older few coats of finish.
Brian d

[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.

[SEAWOLF97]

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

you do nice work , post the Horizon pics when ready.

[Goldjazz]

you do nice work , post the Horizon pics when ready.

Cheers, will do.

[corvettedcg]

I still think that the 4310 and 4311 look much more "dignified" in their grey attire. If you really want to put the icing on the cake, try one of the "improved" L100 style crossover upgrades , the one with resistors and inductors (besides the caps). In my own experience, I think the new crossovers bring the monitors to a level of performance that they truly deserve. If you want to try it on the cheap, pick up a pair of L110, L-50, or 4313b crossovers on eBay (less than $75.00) and give it a listen. Either way, enjoy those monitors, they look super! Paul

Paul, I know this thread is over a year old, but I just wanted to say your Wave license plate grabbed my attention as I have the same style plate (I'm in Garden City). Howdy neighbor!