B380 restoration

[Mike F]

I rescued a badly beaten, used and abused orphaned B380 cabinet today. No driver,processor, grilles or mounting hardware were included. As nasty as it is, the structural integrity has not been compromised so I deemed it fit for a Resurrection.
It`s going to take some work to get it to become presentable again but I think it`ll be worth it :)

What I really need to know at this point are the dimensions of the grilles and what the port/woofer cut-outs look like. Also, one grille peg is sheared off flush with the baffle. Are these just press fitted in?
Any information would be most welcome.7184671847

[Tweak48]

Hi Mike-

Approximate measurements are as follows (no metric measuring tape unfortunately): 18.75" x 20.75"; 8.25" x 20.75" Depth as shown in photo. Grille frames are two piece particle board construction with corner bracing. You'll probably need a router for the bull nose edges. As you can see, I have problems of my own to deal with, but I appear to be in better cosmetic condition. I use mine for a HT sub. My AVR determines the crossover point and don't need the outboard crossover. So all I needed was a mono power amp. As for the peg, I'd just drill the old one out, and glue a new on in.

Good luck and let me know if you need additional data. BTW, if you're not interested in doing an accurate cosmetic restoration, Parts Express has a decent generic replacement grille kit.

Bryan

http://i160.photobucket.com/albums/t181/tweak48/HiFiStuff/20160601_101130_zpshqtvhvlj.jpg (http://s160.photobucket.com/user/tweak48/media/HiFiStuff/20160601_101130_zpshqtvhvlj.jpg.html)

http://i160.photobucket.com/albums/t181/tweak48/HiFiStuff/20160601_101336_zps3xxmarpq.jpg (http://s160.photobucket.com/user/tweak48/media/HiFiStuff/20160601_101336_zps3xxmarpq.jpg.html)



http://i160.photobucket.com/albums/t181/tweak48/HiFiStuff/20160601_101008_zpsfg14ikpy.jpg (http://s160.photobucket.com/user/tweak48/media/HiFiStuff/20160601_101008_zpsfg14ikpy.jpg.html)

http://i160.photobucket.com/albums/t181/tweak48/HiFiStuff/20160601_101356_zpscgi257fr.jpg (http://s160.photobucket.com/user/tweak48/media/HiFiStuff/20160601_101356_zpscgi257fr.jpg.html)

[Mike F]

Thank you so much for that, Tweak, it`s the first time I actually see the grille frames. It appears that each are composed of 2 frames, would that be an approximately 1" frame perimeter?

I was doing some peg spacing measurements on the baffle and the port side, inner pegs are off by a significant amount (close to 1cm) with respect to the outer pegs.
That would account for the broken peg as the port side grille could only go on in one position.
71852

[Joseph Smith Jr]

The grille peg is a simple friction or press fit

JBL did not glue them in

Readily available on-line or can be salvaged from another old cab of the period - DO NOT glue them in, you, or someone, may just need to remove them again some day, gluing ups the chances of baffle chipping and damage after all your work to make things look nice and doesn't do a thing to make them stay in place any better

Glue doesn't adhere to that nylon like material anyway

[mech986]

There are some instances where JBL made the peg locations slightly asymmetrical to make sure the grille only goes on one way, either for fit or correct orientation.

Regarding the pegs, if you don't glue them in, then be sure to undersize the hole a little for a very tight fit. Original pegs were cylindrical and in many cases were glued in, that's why they don't come out easily and many times break after becoming brittle. Some of the pegs that JBL sells/sold more recently have a multilayered feather type insertion section that goes in easier and resists pullout, but I'm not sure they hold that well in the long run without adhesive. Contact cement may work well as might yellow carpenter glue.

There are new Delrin plastic peg versions available from seller sign-shop on ebay, pricey at $3 or 4 per, but very sturdy. I've used them in the past and they work well. I know of no other fully original looking replacement other than the fluted ones JBL now sells as replacements.

If you have pegs that have fully broken off or are stubbornly resisting removal, use a screw or stud extractor device like the Alden Grabit or Grabit Pro, that makes the removal process painless, and doesn't disturb the original hole, even if the peg was glued in. I prefer the Alden US made product because IME, they are made better and are more durable than the cheap Chinese knockoffs.

http://www.aldn.com/Images/Large/8440P.JPG

[Joseph Smith Jr]

Easy outs are over kill for this job and expensive
Also requires fairly accurate drilling (well centered) which isn't always so easy depending on how the peg is broken

No need to buy a 20 dollar tool to fix a problem when there's a .50 cent solution that works exactly the same and just as well if not better

If it's broken off flush with the baffle make a dent in the broken peg with a center punch, ice pick or small nail, whatever you have on hand that will work, as close to center as you can get it, and drill a small pilot hole in the peg
Screw a wood screw into the hole
Grab the screw with a pair of pliers or vice grips and firmly pull the peg out while turning the screw clockwise
Alternatively, you can screw in a short screw and use the tool discussed below to simply pry out the broken peg using the screw head to grab onto

For unbroken pegs, or pegs broken off above the baffle's surface use a small pry bar or automobile door trim tool with a thin blade
There is a ridge at the top of a good peg for the tool to grab, the same ridge that grabs onto the particle board grille frame

If your peg is broken and the ridge is gone, make a couple of notches with a saw blade for the tool to grab
Use a wood carpenter's shim or similar to protect your baffle from dents while prying out the pegs
The pegs do not get brittle, they are made of nylon

Do not use glue, JBL didn't, and I have removed and re-installed dozens
It is a wedge fit, if your holes are wallowed out then dowel them and re-drill fresh holes the proper size

This is a suitable tool, you can even find this one at Staples, will only cost you between 3 to 5 bucks
Good tool to have in your box
Stanley® Wonder Bar® II Pry Bar, Flat Shape, Tempered Steel, 7"

http://www.staples-3p.com/s7/is/image/Staples/s0470752_sc7?$splssku$

[Mike F]

Good tips Joseph Smith. I`m afraid I got a little ahead of myself with this restoration which, incidentally is moving right along very nicely so far. I refinished the baffle before extracting the broken peg :(. I now run the risk of marring the surface when I do get around to extracting it, but that wont happen before I source a replacement.
The Ebay pegs sure look good but a single one will set me back more than $26 by the time it gets here so I`m trying to source a used one elsewhere if at all possible.

[rdgrimes]

The only limit to the number of uses for a Wonder Bar is your imagination.

FWIW, things like pegs can also be extracted with a wood screw and a pair of pliers. Or construct a small "puller" with a couple small wood blocks and a cross-bar with a hole in it for the screw. As you screw in the screw it pulls the peg out.

[Joseph Smith Jr]

I now run the risk of marring the surface when I do get around to extracting it source a used one
You won't mar the surface of your freshly finished baffle if you put one of these, or something similar, down between it and your pry tool whatever it is
http://s3.amazonaws.com/marquee-test-akiaisur2rgicbmpehea/6q7Rm71RSIC37J5xrGsJ_SHIM.jpg

[Joseph Smith Jr]

Good tips Joseph Smith. I`m afraid I got a little ahead of myself with this restoration which, incidentally is moving right along very nicely so far. I refinished the baffle before extracting the broken peg :(. I now run the risk of marring the surface when I do get around to extracting it, but that wont happen before I source a replacement.
The Ebay pegs sure look good but a single one will set me back more than $26 by the time it gets here so I`m trying to source a used one elsewhere if at all possible.
Look for and talk to folks with gutted cabinets up for sale
I recently did a set of cabs and after I put the pegs back in I notice one of them was sitting too low. I thought what the hell is this? I mean I didn't re-installed them with a sledge hammer!
Upon close close inspection I could see that JBL had actually repaired that hole at the factory, had re-drilled it and doweled it! With a loupe, I could see the faint line of the dowel. In the process, they had also made the hole a little deeper than all of the others. I used a shim and a pry tool, made the height adjustment and now all is well
It will work fine, don't fret over it just relax, drill a pilot with a very small bit and pull it out
Easier than pulling the cork out of a wine bottle

[Joseph Smith Jr]

Or construct a small "puller" with a couple small wood blocks and a cross-bar with a hole in it for the screw. As you screw in the screw it pulls the peg out.
That's a good idea too but it can be a pain in the ass, overly complicated. The problem is the peg starts to turn in the hole before the screw can start the pull. You then would need to have your bar threaded to fit the screw so that the pulling force is applied regardless of if the peg starts to turn, this would require the use of a screw with a machine thread and that's not so good for what we're doing here, it's difficult to get a machine thread started into this material and then we're back to overkill with taps, extractors etc

You'd also need to screw around and get the height just right for the homade puller, have a screw of the requisite lenth on hand, it's just making something very simple overly complicated.

That same potential obstacle exists with my use of a wood screw and vise grips approach, that is why I say start with a small pilot hole and work your way up until you get a hole the wood screw can go into and grip well enough without turning and hold well enough to allow for pull out
If you have reasonably strong fingers and hands you can pull those pegs out bare handed, that's what I always try first with unbroken pegs
Either way, with a little careful thought and shade tree engineering it can be done quit easily with items lying around in most junk drawers and work benches
Some small sharp drill bits, a wood screw and a pair of pliers

Cannot emphasis enough how important it is to use SHARP drill bits for this sort of work

It's just a 9mm OD nylon plug pressed into a 8.5mm ID hole, you don't have to jump through hoops or buy expensive tools to get them out

[Joseph Smith Jr]

Good tips Joseph Smith. I`m afraid I got a little ahead of myself with this restoration which, incidentally is moving right along very nicely so far. I refinished the baffle before extracting the broken peg :(. I now run the risk of marring the surface when I do get around to extracting it, but that wont happen before I source a replacement.
The Ebay pegs sure look good but a single one will set me back more than $26 by the time it gets here so I`m trying to source a used one elsewhere if at all possible.
There's a guy in Canada selling a used single right now
He wants too much for it, but it's still better than $26

[Joseph Smith Jr]

Good tips Joseph Smith. I`m afraid I got a little ahead of myself with this restoration which, incidentally is moving right along very nicely so far. I refinished the baffle before extracting the broken peg :(. I now run the risk of marring the surface when I do get around to extracting it, but that wont happen before I source a replacement.
The Ebay pegs sure look good but a single one will set me back more than $26 by the time it gets here so I`m trying to source a used one elsewhere if at all possible.
PM me your mailing address, I will try and find you a couple of pegs, no promises but I will try
Joe

[mech986]

While I don't disagree with all of the other methods mentioned here, and most are ingenious, the price of the Grabits is fairly small, and you can buy them individually if needed. Also, the use of the Grabit is quite quick, drill a pilot with one side of the tool, turn the tool over, and then reverse drill till it bites, and then the plug pulls out. I pulled 8 broken plugs in a pair of L300's in less than 5 minutes.

Besides that, the first time you run into a stripped headed fastener (and a few JBL screws and bolts have done that to me) you'll be happy to have that tool in your box. I'm as much of a DIY guy and improviser as the next guy, but I learned a long time ago that the right tool for the right job pays dividends in time and frustration.

Now keeping tools organized so that they are findable and at hand, that is still a work in progress.

[Mike F]

After some debate, I decided that reproducing the original grilles was beyond my ability and designed a more realistic one-piece .75" MDF frame, nothing fancy but solid and functional.
I still had some electric blue fabric left over from the 4311 restoration but decided against using it for this project, the sub is already big enough and doesn't need any additional attention :) which brought me to a local fabric outlet where I found some really nice navy blue material. A little stretchy in both directions, it doesn't have the weave pattern nor the density of what my previous 4425s had but the color is beautiful, I`m really looking forward to dressing the new frame.

7199371994

[mech986]

Grille frame looks very nice. Will you be rounding over the outside facing edges?

[Mike F]

Grille frame looks very nice. Will you be rounding over the outside facing edges?

You mean like this ? :)

71995

[Joseph Smith Jr]

While I don't disagree with all of the other methods mentioned here, and most are ingenious, the price of the Grabits is fairly small, and you can buy them individually if needed. Also, the use of the Grabit is quite quick, drill a pilot with one side of the tool, turn the tool over, and then reverse drill till it bites, and then the plug pulls out. I pulled 8 broken plugs in a pair of L300's in less than 5 minutes.

Besides that, the first time you run into a stripped headed fastener (and a few JBL screws and bolts have done that to me) you'll be happy to have that tool in your box. I'm as much of a DIY guy and improviser as the next guy, but I learned a long time ago that the right tool for the right job pays dividends in time and frustration.

Now keeping tools organized so that they are findable and at hand, that is still a work in progress.
I've invested heavily in just about every swanky incarnation of easy outs there is and they all have left me wanting
The biggest problem with all of them is getting a clean straight pilot hole without the tool walking on you and marring the surrounding surface, including the sets that come with their own drill guides and bits
They all will work reasonably well, sometimes, on softer materials, but so will a sharp drill bit and self tapping screw, so, in my mind, why waste the money when all you need is a sharp drill bit, a center punch of sorts, a steady hand and a self tapping screw, that or a tap and a small machine screw
You don't need to spend 20 bucks to pull out broken plastic bits, that is all I am saying

[Mike F]

Everything came together in the past week, sanded the cabinet down with a palm sander using progressively finer grits followed by a generous application of Watco Oil finished off with some Feed n Wax.
In the mean time, I managed to source a freshly reconed 2231a motor assembly with a C8R2235H kit at a very reasonable price, I believe that would please the JBL Gods as an acceptable substitute for a 2235. I did however polish up the outer rim a little which gave the driver a newer look.
I`m particularly pleased at how the grille turned out. Using a single panel frame wasn't the compromise I initially thought it would be at all, it gave it a 434x type look :).

The subwoofer is currently handling LFE duty in a HT system. Bear in mind that I live in a small condominium with neighbors all around me so the 2235s lack of ultimate XMAX wont ever be a factor. I have yet to run it through it`s paces but the few times that I did turn it on, it pressurized my 18`x 10`room quite effortlessly (compared to the little 10" Peerless sub before) even while driven by a lowly Peavey CS-800. I`ll throw a BGW 750B on it just as soon as I finish restoring it or maybe the monster White Oak modified Phase Linear 700B :)

A DBX DriveRack will be simulating a BX-63 just as soon as I track down a response curve, if someone can point me in the direction of one, I`d be obliged.
Here some pictures, I`ll put up some more later.721627216372164

[grumpy]

BX63 info

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=54216&stc=1&d=1324902641 (http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=54216&stc=1&d=1324902641)

[JeffW]

Nice job, great save!

I was just in your fair city last weekend, at least the parts from the Fairmont QE Hotel to the Ile Notre-Dame. Had a good time, needed more clothes :D

[mech986]

Very nice work, looks factory fresh!

[Mike F]

BX63 info

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=54216&stc=1&d=1324902641 (http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=54216&stc=1&d=1324902641)

Thanks for that Grumpy. Looks like an 18db HPF at 20hz followed by a +6db bump at 25hz. It appears that the subsonic filter is altering the 25 hz boost but I`m not sure if the non linear slope above that point is an error in the drawing or an intentional filter. I highly doubt the effect would be audible were it the case of the latter but it most likely can be simulated with the addition of another filter.
The 25hz boost bandwidth ought to be easily duplicated using my 1/6 octave RTA.

[grumpy]

There's some useful information in this thread as well (no need to over complicate things) :)

http://www.audioheritage.org/vbulletin/showthread.php?610-BX63-replacement

[Mike F]

There's some useful information in this thread as well (no need to over complicate things) :)

http://www.audioheritage.org/vbulletin/showthread.php?610-BX63-replacement

You're absolutely right Grumpy, OCD is a bitch I tell you :(

I came across this graph which is more detailed:
72208