Baby Blues (JBL 4301B) in the House!

I wouldn't worry about it. You mentioned yours were from a professional recording studio. No way were they subjected to the harsh environmental conditions that caused the inductors to come unglued in mine and the creation of the capacitor stalactites.

I recap all the vintage speakers I restore just as a general practice for my own peace of mind. Plus, I enjoy doing it. So, I would have done these anyway, and I already have spare L-pads on hand. So, unless there is some hidden damage to the drivers or inductors, this restoration isn't going to cost me any more than my original planned budget.
I'm sure they're fine, and I won't do anything unless I see something needing attention, but I'm curious.
They are great sounding small monitors, you'll be very happy with them.
 
I purchased these 4313B's from Lifer70 and I believe he repainted the baffles. If so, he picked what I think is a fantastic color.
EDIT: lifer70 just informed me that these are the original blue.
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Those are gorgeous! I didn't think they were repainted.
You haven't talked about these much, how do you like their sound? Can you do a video and post it in the video thread? I'd love to hear them!
Glenn
 
They really are Glenn. I couldn't recall what he had told me about that aspect. All I know is they look great like that. The blue lights up with daylight and a camera flash but gets more subdued with regular house lighting in the evenings. My phone camera kept wanting to lessen the blue when it focused on them but I finally got some shots that showed off how they really look.

I have been working on putting together some videos for that great video thread Glenn and will include these that reside here in my home office. Because of the old original spring terminals these unfortunately use (may need to change that) they never go on the main system where my cables only have banana ad spade ends to them and are too much a pain in the arse to change (wood case on amp).

MCM's look great and I vote to keep the original blue. I am surprised Kenrick goes so bright with theirs actually.
 
I would check a local auto body shop supply store for the baffle paint. I've used them for a car I restored and got a custom color to match an engine I was painting. I just brought them the paint code and they were able to match it perfectly. It was only about 20 bucks or so IIRC. You should be able to get an exact match in a rattle can for pretty cheap (MUCH, MUCH less than the $179 from Kenrick) and they usually come with a nicer spray nozzle than the stuff from the big box stores.
 
I pulled the L-pads from my orphan 4411, and as suspected, they are quite a bit larger than the original L-pads on the 4301Bs. In fact, the dimensions are identical to the 50W L-pads Parts Express sells. Both the 4411 and Parts Express L-pads I have on hand have the longer 1" shafts. So, if I need to replace the original L-pads, I will need to get some spacers of appropriate length so the knobs will be flush with the front of the cabinets.

I am getting ready to order some binding posts to replace the stock spring terminals. This is another upgrade I do on all of the vintage speakers I restore. It opens up the possibility to use banana plugs and spade lugs, plus I just think they look classier.

In the past, I've always used the Dayton Audio BPA-38G HD Binding Post Pair Gold from Parts Express:

bpa-38g_photo_2_2.jpg


They are well made, sturdy, attractive, easy to install and very affordable. I used them on my L36 Decades, KEF 104/2s, etc. They also come in polished nickel and satin nickel finishes. The polished nickel matches the polished nickel finish on the original spring terminals, but I'm thinking about going with the satin nickel finish this time:

091-1247_HR_0.jpg


091-1247_ALT_1.jpg


For comparison, here's what they look like in polished nickel:

091-1246_hr_0.jpg


091-1246_ALT_1.jpg


So, what do you think? Stay with the standard gold finish I've been using, be true to the originals and go with polished nickel, or try something new and go with the satin nickel finish?
 
I think the nickel finish is more attractive, but I'm sure they work the same.

I use these (removed from the plate) for an "improved original" look and function. (Part # 091-1142.) I also like the fact that they won't loosen as the screw types tend to (at least they do on my speakers):

These heavy-duty spring loaded terminals are ideal for replacing broken loudspeaker driver terminals or for customization. The nickel plated posts are pre-mounted in pairs onto a strong plastic insulator/base. 3/16" holes in the polarity-marked pushbutton binding posts accept up to 8 AWG wire and hold it firmly. 13/16" solder tabs are attached to 1/8" high standoffs, and voice coil tinsel leads may be soldered to the tabs, crimped, or both. A 1/8" diameter hole in the base facilitates mounting to the loudspeaker chassis via screw or pop rivet.

091-1142_HR_0.jpg
 
I think the nickel finish is more attractive, but I'm sure they work the same.

I use these (removed from the plate) for an "improved original" look and function. (Part # 091-1142.) I also like the fact that they won't loosen as the screw types tend to (at least they do on my speakers):



091-1142_HR_0.jpg

Those look pretty much exactly like the original JBL spring terminals I am planning to replace. In what way is the function improved compared to the originals?

I would prefer something that permitted the use of banana plugs and spades. I mostly use mine with BFA style banana plugs, but have also used them with bare wire of various sizes and have never had the Dayton Audio BPA-38G binding posts become loose. I have had other lesser 5-way binding posts work their way loose (the factory installed binding posts on the Pioneer SP-BS22-LR are the worst I've owned), but not these.
 
Yeah, I said they sometimes tend to loosen on me; no one else seems to have the same complaint.

The barrels might be a tiny bit larger, the mounting screws might be slightly larger diameter, but the wire holes are definitely much larger and penetrate both sides of the barrels. They're basically the originals, on steroids.
 
Yeah, I said they sometimes tend to loosen on me; no one else seems to have the same complaint.

The barrels might be a tiny bit larger, the mounting screws might be slightly larger diameter, but the wire holes are definitely much larger and penetrate both sides of the barrels. They're basically the originals, on steroids.

The inability to use banana plugs makes those a non-option for me.
 
I pulled the L-pads from my orphan 4411, and as suspected, they are quite a bit larger than the original L-pads on the 4301Bs. In fact, the dimensions are identical to the 50W L-pads Parts Express sells. Both the 4411 and Parts Express L-pads I have on hand have the longer 1" shafts. So, if I need to replace the original L-pads, I will need to get some spacers of appropriate length so the knobs will be flush with the front of the cabinets.

I am getting ready to order some binding posts to replace the stock spring terminals. This is another upgrade I do on all of the vintage speakers I restore. It opens up the possibility to use banana plugs and spade lugs, plus I just think they look classier.

In the past, I've always used the Dayton Audio BPA-38G HD Binding Post Pair Gold from Parts Express:

bpa-38g_photo_2_2.jpg


They are well made, sturdy, attractive, easy to install and very affordable. I used them on my L36 Decades, KEF 104/2s, etc. They also come in polished nickel and satin nickel finishes. The polished nickel matches the polished nickel finish on the original spring terminals, but I'm thinking about going with the satin nickel finish this time:

091-1247_HR_0.jpg


091-1247_ALT_1.jpg


For comparison, here's what they look like in polished nickel:

091-1246_hr_0.jpg


091-1246_ALT_1.jpg


So, what do you think? Stay with the standard gold finish I've been using, be true to the originals and go with polished nickel, or try something new and go with the satin nickel finish?

Since the Dayton heavy duty speaker binding posts are so inexpensive, and I always seem to have at least one more pair of speakers in my project queue, I went ahead and ordered two pairs. I bought one of the gold finish, since I've used them many times and like the way the look. And, I also ordered a pair in the satin nickel finish to give something new a try.

I'll probably use the satin nickel ones on these JBL 4301B Control Monitors and the gold ones on a pair of Rectilinear III Highboys I am working on. If I don't like the satin nickel look on the 4301Bs, I'll just swap them out for the tried and true gold ones.

BTW, if you want to save a buck on shipping on a small order, order them from Parts Express on Amazon. For some reason their minimum shipping fee is a buck cheaper on Amazon than through their own web site.
 
I purchased these 4313B's from Lifer70 and I believe he repainted the baffles. If so, he picked what I think is a fantastic color.
EDIT: lifer70 just informed me that these are the original blue.
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I really like the way the silver frames of your driver's stand out against the blue background.

I haven't even heard my 4301Bs yet and I'm already itching to move up to a pair of 4313Bs.
 
Thought you would like to see the original 4301's, I bought in 1978 Sn# 25027,25028
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Thanks for sharing the photos of your 4301s. I had mentioned in one of my earlier posts that I prefer the classic JBL badges (same as the ones on my L36 Decades) over the plastic strip across the bottom of the grills.

I've been kicking around a few ideas in my head on how I want to do the grills on these guys. It may be blaspheme to the JBL purists, but I'm considering other non-original colors for the grill cloth (again, like I did with my L36 Decades). These are going to be in my living space (most likely my master bedroom) and since I don't live in a recording studio, I don't necessarily want them to look like studio monitors.

We'll see. I may try a couple different color grill fabrics and see which I prefer. They're grills after all. They can be easily swapped or replaced.
 
Posting to follow along as I have no doubts these will be gorgeous in the end. I'm also with you on the colour. I think somewhere between original and the modified ones you love would not only be unique but a fantastic modern interpretation!
 
Ha! Look what I found:

JBL_L19_Crossovers.jpg


That's a pair of mint condition JBL L19 crossovers. They were on eBay, but local. So, I pulled the trigger and picked them up.

For those not familiar with the L19, it was the home version of the 4301B. It shared the same drivers as the 4301B, in a slightly different cabinet. The crossover networks are identical except for the woofer shunt cap - 18uF NPE for the L19 and 16.5uF mylar film in wax for the 4301B.

Since, I am recapping mine anyway, I really don't care about the caps. Given the obvious heat damage to the caps in my original 4301B crossovers, the failure of the glue attaching the inductors and the corrosion/mildew on the outside of the L-pads, I was concerned about the condition of the original inductors and L-pads. They might still be within spec, and maybe the L-Pads could be cleaned, but even if they are 100% functional today, I would always worry about long term reliability.

Why take a chance? I figured it was worth 25 bucks and a short drive on a nice day for the peace of mind that I'm starting my restoration with mint condition parts - brand new caps and the L-pads and inductors from these L19 crossovers. I'm going to be putting considerable time and money into this project. So, I want to start out with the best possible parts my budget will allow. I'll still open up these "new" L-pads and clean and lube them, like I did with my L36 Decades, but I'll feel much more confident that I won't have to replace them 6 months from now.

Now, I just need to find my glue gun and zip ties...
 
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Finally, a little actual progress to report. I just refinished rebuilding the first 4301B crossover network. Here's what it looks like:

JBL_4301_B_Crossover_After.jpg


I oriented the inductors at 90 degrees to minimize field coupling and mutual inductance. I don't have a photo, but on the original crossovers, they were physically touching and placed parallel to each other. Not a lot of room to physically separate them, but at least now they aren't actually touching each other and oriented at the desired 90 degrees.

As previously mentioned, I went with a 7.0uF Sonicap Gen 1 bypassed with a 0.01uF Vishay-Rodertstein MKP1837 in the tweeter circuit and a pair of parallel 8.2uF Mundorf E-Caps bypassed with a 0.1uF Vishay-Rooderstein MKP1837 in the woofer shunt circuit.

I also replaced the 39-year old 5.0 ohm 10W cement resistor with a 5.0 ohm 12W Mills non-inductive resistor.

Although it's possible spray Deoxit in through the vent openings in the L-Pads, I removed the covers and gave them a thorough clean and lube before reassembling them. I also like to visually inspect these 35 - 40 year old L-pads to make sure there aren't any potential issues. As expected from the outward appearance, the insides were also in excellent condition. There was the expected oxidation on the windings, but the Deoxit took that right off.

I also received the Dayton heavy duty binding posts I ordered from Parts Express. These are very well made binding posts and a heck of a great deal at $5.95 a pair. I looked at other binding posts from other manufacturers, but I really cant see spending $40 - $60 a pair when these Daytons are so well made and so inexpensive. I really like the look with the satin nickel finish and plan to use those for this pair of 4301B Control Monitors.
 
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Any updates on these bad boys? I'm currently listening to my 4301Bs for the last time with the old caps in the crossovers. I'm going to see Pink Martini in concert tomorrow night. Then, Saturday is overhaul day! I can't wait!
 
Any updates on these bad boys? I'm currently listening to my 4301Bs for the last time with the old caps in the crossovers. I'm going to see Pink Martini in concert tomorrow night. Then, Saturday is overhaul day! I can't wait!

Progress has been very slow. I just started a new job on Monday and am moving into my new place this weekend. Once I get settled in and have access to my tools and a garage to work in, I hope to be more productive in my various projects.

I have made a little progress since my last post. I finished rebuilding the second crossover and removed the old foam and glue from the frames and cones of the woofers. I have the replacement surrounds and just need to find some time in the next week to get them installed. Then I will finally get to hear these little guys do their thing.

Where are you seeing Pink Martini?
 
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