View Full Version : Restoring a pair of 4401s

09-30-2005, 05:42 PM
Hi everyone, I am new to this site. I have a pair of 4401s (which seem to be the studio version of the L15), and want to restore them to their former glory. I haven't had a pair of JBLs for may years, and look forward to putting these in my living room, driven by a homebrew 6BQ5 tube amp.

I have a couple of questions for the collective wisdom of this group.
1. How do you remove the L-Pads? They seem to be held in by a nut (I have a speaker parts diagram), but I am unable to grab it with my sockets. Any idea of the size?
2. One of the L-Pad is very scratchy. Do these respond well to D5 cleaner, or do they need replacing? Are they still available?
3. One of the knobs is broken. Anybody here parted out a 4401 and have a spare knob? JBL doesn't have any.
4. Any suggestions on refinishing wood? I have refinished a few old tube receiver cabinets, and generally know what I am doing, but is there any gotches on these walnut cabinets? I have a few dings to patch with veneer, and some scratches to fix.
5. I was going to replace the capacitors in the xover. Any suggestions on brands and sources?

Thanks from a newbe.


10-03-2005, 02:44 AM
Hiya, Randy. Recently picked up a pair of these locally myself. Nice little monitors, they are. Well worth rehabbing. :)

1) You may get better access from the inside after removing the woofer. Looks like it'll need a special wrench to get in that recess from the front.


2) They do respond to cleaner, but you have to open them up to get it good.

3) Yeah, that elongated knob is gonna be hard to find. If you have access to a lathe, turn a pair of sharp-lookin' aluminum ones yourself outta round stock, maybe. Gotta knurling tool? :)

4) Lotsa threads on refinishing here on the forum, including the formula for JBL walnut finishing oil.

5) I'm using Dayton metalized polypropylene from Parts Express lately, very reasonably priced. For the 14 uF, you'll have to use two in parallel, like a 10 uF and a 4 uF, becasuse that's not a standard value. The 8 uF's gonna be two 4's, and the 32 uF a 30 and a 2, maybe For the 0.068 uF bypass capacitors, try the AudioCap "Theta" film and foils they sell. Use 0.01 uF instead. Sure you want to do that?

I believe a better alternative biased crossover for these mini-monitors was suggested earlier in the forums, which you might want to build from scratch instead....

10-04-2005, 06:33 AM
Thanks Zilch. I did get the L-pads out, and the are 15/32", an odd size socket. You need a deep one, not standard size. It also helps to use a razor blade to (gently) peel back the label, unless you have a very thin walled socket.

Thanks for the .pdf of the xover schematic. You mentioned an alternative xover design, I was unable to find it on the site. Could you forward the link? I can fab one from scratch if needed.

I think the knobs can be fabbed from wood or plastic stock easily, but I was trying to find an original, if possible.


10-04-2005, 09:26 AM
It is former member Giskard who is the mini-monitor specialist and avocated the alternative crossover design. I'll nose around a bit and see if I can find it here....