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Ralphh
05-06-2005, 09:08 AM
HI All,



I'm new to this forum and I'm looking for your input. I have been slowly acquiring the components for a pair of L100's with the intent of building my own cabinets. I enjoy woodworking, and I've read a number of threads by individuals who have restored existing cabinets. Has anyone here build their own L100 cabinets? I was thinking of using cabinet grade plywood instead of the original particle board and applying walnut veneer. Any input would be greatly appreciated.

pmakres1
05-06-2005, 09:50 AM
Hi Ralph, Welcome to the forum!

JBL has contended that they use dense compressed wood, also known as particle board, because it is "superior to solid wood in its acoustic properties". I assume that they also considered it superior to plywood as well,
for acoustic reasons. I'm sure some other members will chime in on this subject.

Good luck on your project!

Peter :)

Titanium Dome
05-06-2005, 10:10 AM
Having built some speaker cabs myself (though not L100 style), I know firsthand how unattractive solid wood cabs can sound. Also, on one pair we tried a plywood baffle, and man did it suck. It was not, however, cabinet grade plywood. It was "filled" plywood with no voids, though.

It seems like MDF is best.

jackgiff
05-06-2005, 10:38 AM
As long as you are planning to veneer them, MDF might be your better choice of materials.

Mr. Widget
05-06-2005, 11:14 AM
Unless you are doing something custom... it seems strange to me to build copies of the most readily available speakers JBL has ever produced. With a little luck you can get the empty cabinets practically for free. If you are going to build something yourself why not go a bit up market? JBL has better 12" woofers, mids and tweeters.

As for wood I would second the motion for MDF. It is better acoustically than particle board or plywood.

Widget

JBLnsince1959
05-06-2005, 11:21 AM
Ditto - MDF will sound the best

pmakres1
05-06-2005, 11:22 AM
I knew this would be unanimous!

saeman
05-06-2005, 11:42 AM
Hi Ralph: Will add my two cents worth - it's free. Have built a few pairs of L100's over the past few years - coz I personally feel that they're an awesome small size monitor AND with the scrappers out there on ebay, there seems to be an endless supply of L100 components. If you pay attention to detail you can produce a pair that will be identical to the originals and only the experienced eye will know the difference. From my observations JBL made changes in the way they produced the cabinets. Early models had veneered P.B. sides and tops, painted P.B. backs and a multi layer (10-12) baltic birch type of baffle. The later models used P.B. for the baffle. While MDF is dense and has properties that are attractive for speaker cabinet building, it is very poor when it comes to holding a screw and it does not have good glueing properties (or should I say not as good as P.B. or plywood). The baffle on the L100 has a relatively small surface area, and the enclosure is ported. You'de be hard presed to get any resonance/vibration out of that baffle if it is properly braced and the entire cabinet is built true and solidly glued. I have hunted down all kinds of expensive low/no void plywoods, I have veneered baltic birch, and have laminated baffles up to 1 1/4" thick in an attempt to satisfy the worries of not having a solid baffle. I believe it all goes back to selecting a good material and PROPERLY BRACING the baffle and interior cabinet walls. Different considerations apply if you're building a sealed cabinet using a passive or building a 10 cu-ft and up enclosure and hanging four 130A's on the baffle, but you're talking L100's. Most of JBL's big pro monitors used 3/4 baltic birch for the baffle (well braced in most cases but could be improved somewhat) or 1" P.B. Having owned and/or heard most of their big monitors and cranked them to their limits too!!! I would say that neither your ears nor the plaster on your walls could take the sound pressure levels that it would take to yield any audible resonance if the cabinet is solid and well braced. If you choose to do your veneering after the enclosure is built, you can build the entire box out of 3/4" P.B. with a table saw and router, with NO mitered joints and no screws/dowels, just glue (internal braces should be glued and screwed to their surfaces). I've done it this way many times and the results were awesome. Making the grills is really more work than the cabinets. Will be glad to help you if I can. Rick http://audioheritage.org/vbulletin/images/smilies/smile.gif P.S. Opinions are like a_ _ holes, everyone has one.

Ralphh
05-06-2005, 03:26 PM
Thank all of your for your feedback.
For those wondering why I would go to the trouble of building the L100 cabinets, let me explain. First, I enjoy woodworking. Second, I have a friend with a pair of L100’s which I will measure and create a set of construction drawings. Third, after watching eBay for several months, I concluded that I could purchase the components and build new cabinets for less that amount that the really good L100’s were going for, after freight is added to the purchase price. I could purchase a pair that was in need of restoration, but most of these had some flaws in the components that would I would want to have repaired or replace. Currently, I have acquired a pair of Century L100 crossovers with the metal name plates, a pair of 123A-1 woofers, a pair of LE25 tweeters with new foam rings, grille mounting posts, and new foam grilles. I could still change my mind and sell these items if the right pair of L100’s came along.


One other question that I have, is there a baffle or an enclosure behind the midrange driver in the L100’s?

saeman
05-06-2005, 03:31 PM
The mid range sits in it's own sealed chamber behind the baffle. It is about 5" inside diameter (would have to check my notes). Made of a piece of cardboard tube with wall thickness about 1/16", blanked off in the back. It's real easy to make.

57BELAIRE
05-07-2005, 10:12 AM
Unless you are doing something custom... it seems strange to me to build copies of the most readily available speakers JBL has ever produced. With a little luck you can get the empty cabinets practically for free. If you are going to build something yourself why not go a bit up market? JBL has better 12" woofers, mids and tweeters.

As for wood I would second the motion for MDF. It is better acoustically than particle board or plywood.

Widget

I think Widget's right on here.

By the time you buy all the materials and spend time measuring, cutting, gluing and sanding, you'll have a couple of expensive (counting man-hours) small boxes that you could have purchased outright for less.

I'd opt for constructing a larger format monitor utilizing 15's and compression drivers.

L100's are nice but...no comparison
:bouncy:

mike
05-07-2005, 10:37 AM
L100's are fairly common on Ebay but to find a pair in really nice shape and have them shipped to you without getting damaged is not that easy. A lot of people are surprised to find out just how good L100's can be when set up right and driven by good electronics. Over the years I've seen a few pairs make it into truly high end systems.

Mike

Mr. Widget
05-07-2005, 11:52 AM
I certainly can relate to the pride of having created something yourself, and if you really feel that the L100 is the speaker for you then I guess you should do it. I would use MDF or Baltic Birch, Finn Ply, or what ever the locally available brand of all birch plywood is and not cabinet grade plywood. I would also not use Apply Ply. These plywoods are not very dense. There used to be an all maple product from Canada that was exceptionally good, but I believe they have ceased production.

You mentioned having the foilcals... are they in new condition with no wrinkles? They tend to get mangled in the removal process. Once wrinkled they will not look new again. That would drive me crazy...

Widget

Ralphh
05-07-2005, 12:09 PM
The foilcals I have are perfect. One is completly flat and the other has a slight curl to it. Neither one has any wrinkles in them.

Mr. Widget
05-07-2005, 12:47 PM
That's lucky... show us pics when you're done! :thmbsup:

Widget

Ralphh
06-07-2005, 09:40 AM
My thanks to all of you for your response and opinions. I now have all the required components and I'm in the process of creating CAD construction drawings from measurements taken from a friends L100's. Since he doesn't want to remove any of the drivers from his speakers, I have the following additional questions that I hope someone can help me with. 1) Is the front panel (baffle) 3/4" or 1" thick? 2) What is the depth of the enclosure tube that is behind the midrange driver? And 3) Are the wires to the midrange driver sealed where they pass thru the wall of the enclosure tube?

Your response will be greatly appreciated.

JuniorJBL
06-07-2005, 09:57 AM
I would think that almost any le5x from a later vintage L100 L250 etc. would have the same depth tube as they usualy use the cutout from the baffle to seal the rear of the tube. If this is the case I can measure my L250's and give the measurement:)

pmakres1
06-07-2005, 10:23 AM
Are the wires to the midrange driver sealed where they pass thru the wall of the enclosure tube?


I can tell you that in my L220's the wires to the midrange driver are sealed where they pass through the wall of the sub-chamber. Some type of grey putty was used, probably silicone.

This is also the case with my 4313B's.

Peter :)

Akira
06-13-2005, 11:02 AM
since i own a touring company MDF is out of the question. we use 13ply russian birtch. very expensive but every bit as good as MDF and quite superior for strength and bracing, especially when constructing a small box...plus it makes a good natural finish...no veneer.
my L100's use 3/4" walls with a 1" baffel...don't know why
p.s. i would use a 2405 slot, the absolute best high end ever. i don't feel the 6K cross over point is bad, even though the recommended point is 7K. the gain is reduced and the rough oscillating sound comes in at 5K.

Ralphh
06-22-2005, 05:00 PM
http://audioheritage.org/vbulletin/images/smilies/smile.gif Thanks again for everyone’s input. I now have all the materials and plan to start construction of the cabinets in the next few days. I am using 3/4" MDF for the sides, top, bottom and back, 1" Baltic Birch for the front, and 2-ply walnut veneer for the sides, top & bottom from Rockler Woodworking. I'll post pictures as construction progresses.



Now if “Sonofagun” would start making the foam grilles for the L100’s, I’d be complete.

Ralphh
08-26-2005, 05:34 PM
Well, this project has certainly not gone as fast as I would have liked, mostly due to summer family activities. And not having access to a table saw doesn’t help either.
I have cut the top, bottom and side pieces for two cabinets from ¾” MDF. These have been cut to the required depth, but are currently longer than the finish dimensions. I cut these with a circular saw and a metal straight edge with excellent results. I decided to make these cabinets ½” deeper that actual L100’s to further distinguish them from the real thing.
Next, I applied the walnut veneer to one top piece with contact cement. Once the cement had cured for a week, I set up and cut this piece to the finish length with corners cut to a 45 deg. bevel. I first laid out the cut line, and then sliced thru the veneer with a utility knife. I then applied a piece of masking tape along the cut line to hopefully prevent any breakout of the veneer from the upwardly rotating circular saw blade. This worked perfectly and resulted in a very clean cut. I’m also using 60 tooth carbide tipped blade in my circular saw.
Another change I’m making in the construction of these cabinets compared to the original L100’s is cutting a rabbit in the front edge of the top bottom and sides for the front baffle to sit in. I have cut a 3/8” x ½” rabbit into the above described top piece, and a corresponding one will be cut into the edge of the 1” thick front baffle panel. This will allow the front panel to site flush with the side panels and give a stronger joint.
With the success of this test piece, I now plan to veneer and cut the remaining pieces. I will post pictures of the construction when I begin the assembly.

Once again, thanks for all your input.

Titanium Dome
08-27-2005, 11:10 AM
...and post those pictures! :yes:

Lancer
08-27-2005, 11:14 AM
p.s. i would use a 2405 slot, the absolute best high end ever.If that were true, I'd be using them. ;)

Zilch
08-27-2005, 12:47 PM
If that were true, I'd be using them. ;)Yeah, me too.

I don't even have any.

[Maybe that's the problem.... :p ]

Lancer
08-27-2005, 12:53 PM
I don't even have any.

[Maybe that's the problem.... :p ]Well, maybe you should keep a pair around for kicks.

Akira
08-30-2005, 10:15 AM
If that were true, I'd be using them. ;)
it's all about the texture that a driver imparts into the mix. the slot sounds like pure air; it opens up the box... no sizzle, spit or sparkle. (but, for best performance they really should be crossed over at 10K) absolute best on hi-hat, 21" rock ride (every drummer, and engineer knows what that sounds like) acoustic guitar harmonics and breathy vocals. for all of these reasons i don't like 044's, but that's just my preference. SO...what do you prefer, and back it up.
new drivers from all high end companies boast 30K plus response...meaningless if the texture isn't there, but maybe they sound great. never heard the new beryllium HF drivers, anyone have any comments.

Lancer
08-30-2005, 12:34 PM
but, for best performance they really should be crossed over at 10KAnd without any passive components between the driving amp and the 077/2405. Use an electronic crossover in front of a very low power amp such as a chip amp. Amps with turn on transients will damage the ring diaphragm.

SO...what do you prefer, and back it up.I simply don't have the time and inclination to get into this with you. Pretty much everything JBL makes today beats up the old ring radiator. I will say that I cannot, off the top of my head, think of anything JBL that can beat the 077/2405 from 10k to 20k with maximum SPL as the requirement.

Some will immediately pick up on the old saying - "JBL always had the bass, that wasn't the problem..." For years, the 077/2405, warts and all, was simply the best thing JBL had regardless of intended application. That limitation went away with the introduction of the 066 many, many years ago. The old slot loaded ring radiator is early 70's technology and JBL has come a long way in the high frequency transducer department. Yes, the 077/2405 is neato, groovy, cool, whatever, but it hasn't been the only game in town for a very long time.

Ralphh
10-17-2005, 02:38 PM
Finally, here are some pictures of my progress on this project. I haven’t glued the front baffle to the box yet. I plan to install the fiberglass insulation to the box sides and back, and install the port tube and midrange driver enclosure to the baffle before it is installed.

sonofagun
10-17-2005, 04:20 PM
Hmmm...interesting. Here's a thought:

With the combined talent and know-how of all here, we should be able to come up with an updated, SOA retromod version of the L100. I can furnish new grilles*. I'm speaking of a redesigned version making construction easier and using new drivers (from any OEM maker) and x-overs to give better performance than the original. Perhaps eliminating the grille frame (with flush mounted drivers no frame is needed) - no diffraction effects.

Whadaya think?


Particle vs. MDF - PB is ok as long as it's high density cabinet grade. Whatever you use here's a tip for stronger joints:

Prime the pieces to join with a slightly thinned down version of the glue first; let soak in 5 - 15 mins; then add full strength clue and clamp - makes for stronger joints. Screws sometime actually weaken joints since they can fracture the wood - modern glue joints are stronger than the wood itself.

*Currently am working with a co. with a CAD/CAM machine to automate the manufacturing process. Can solve L100 grille production problems.

Ralphh
12-13-2005, 07:46 PM
Well, the cabinets and grill frames are finally done. Here are some pictures taken before the finishing begins.

duaneage
12-14-2005, 11:11 AM
I built my 4411 clones from furniture grade plywood on the sides, bottom and top, MDF for the baffle and the rear. I used a 5 inch PVC coupler from and electrical supply house for the midrange chamber, at 85 cu inches it was ideal. I routed the drivers into the baffle board and rather than set the baffle board into rabbit joints cut into the sides, I had the baffle cover the ends of the sides. THis looked a lot better than painting the ends of the sides like the originals.

Ralphh
12-30-2005, 10:38 AM
Well, I'm pleased to report that my L100 project is complete. And they sound wonderful.

First, I have some pictures of the cabinets after they were stained and painted. After sanding with 200 grit paper, I first applied General Finishes "Salem" stain to the walnut veneer and trim. This is available at Rockler and Woodcraft stores. This was followed with 3 coats of General Finish’s oil & urethane satin top coat. This produced the look of an oiled cabinet like the originals, but with a lot more protection.

Ralphh
12-30-2005, 10:42 AM
There's another improvement that I made to these. In the above pictures, you can see that I installed a T-nut for that one crossover mounting screw that is located under the foilcal. In the future, I can now remove the crossover without having to remove the foilcal again.



For the grill frames, I installed black window screen to help support the foam grill inserts.

Ralphh
12-30-2005, 10:46 AM
Below are pictures of the completed speakers with all the componets installed.

Ralphh
12-30-2005, 10:48 AM
And finally, with the grill frames on with "sonofagun's" wonderful foam grills.

John
12-30-2005, 11:59 AM
Cool:applaud:

rockin'rushmore
12-30-2005, 12:37 PM
:applaud: EXCELLENT!

JBLRaiser
01-01-2006, 09:44 AM
I'm new to this site and must say as a JBL Ebayniac, my time will now be split with this site. If this thread is any indication of the quality of the posting of this site, my JBL nirvana is assured. Thanks to all who posted and especially Ralphh for a fantastic job of bringing this project to fruition. Now, if only my L100's looked so good.

Fangio
01-01-2006, 10:41 AM
What a great job, really beautiful veneer. I'd raise my hat off to you (if i had one), and wish i had your talent. :applaud:

chad
01-01-2006, 06:17 PM
Bravo!!

Timeless beauty, timeless fidelity, and the satisfaction of doing it yourself.

You are the man.:bouncy:

Ralphh
01-02-2006, 02:43 PM
I had a request to post a few more pictures. These were taked without a flash, so the color of the wood appears a little different. If it ever stops raining around here, I'll take them outside for a few nature light shots.

Thank you all for your help in the past and your positive comments.

Ralphh
01-12-2006, 05:04 PM
For this project, I used a pair of original L100 crossovers. I tested the L-pads and found them both to be in good working condition. I then installed .01 by-pass caps. as others here have done.

My question, has anyone here replaced the original capacitors in their L100's with new main capacitors? If so, what type and brand did you use? What were the results of this change?

Also, has anyone modified their L100 crossovers to something a bit more complex, and with what result?

Ralphh
05-01-2006, 06:59 PM
After listening to these speakers for several months, I have some comments and a question to the experts out there.

My previous speakers were a pair of L-26's, which I still enjoy. My L-100 creations have more low end and a fuller mid range, which was expected, and is very enjoyable. However, with some music, they have too much bass to the point of sounding "muddy". For this music, I have turned down the bass in my recivers equilizer. Is this the nature of the L100's, or is it my creation? Would adding additional fiberglass insulation help? (I have 2" on the sides and back inside the cabinet)

Thanks to everyone for your constructive imput.

Zilch
05-03-2006, 05:27 PM
I don't see any information regarding the duct and port. I'm tempted to say "Lengthen the duct," but should really model it before advising anything.

Can you provide the net internal volume (after deducting the LE-5 chamber) and the diameter and length of the port tube? Effective length would be through the center of the elbow, if used.

Rationale: JBL tuned L100's bass to sell the product to a specific market in the '70's. That may not be optimum for your contemporary listening....

Ralphh
05-03-2006, 09:47 PM
I used the plastic duct tubes from a dismanteled pair of L100's, that I purchased on that major auction site. The cabinets are the same heigth and width as the factory L100s, but are 1/2" greated in depth. The mid-range enclosure is the same diameter and depth as the factory L100's. The cabinets are constructed from 3/4" MDF for the sides, top, bottom and back, and 1" baltic birch for the front baffle.

Zilch
10-28-2006, 11:47 AM
With some music, they have too much bass to the point of sounding "muddy". For this music, I have turned down the bass in my recivers equilizer. Is this the nature of the L100's, or is it my creation?http://audioheritage.org/vbulletin/showthread.php?t=9463

Close the ports:

http://audioheritage.org/vbulletin/showthread.php?p=122946#post122946

The LF sim is here:

http://audioheritage.org/vbulletin/showthread.php?p=123449#post123449

[Read on, there.... :) ]

Gary L
10-28-2006, 12:33 PM
Hi Ralph. Fabulous job and great pics and this is one of those threads that make this site fantastic.

I love seeing others handywork and yours is right up at the top.

Along the way you had some other say "Go bigger and better". I have to agree with them and especially now after viewing your finished project.

I know the time and effort that went into these and I also know that only you will ever appreciate them for everything they are.

I honestly don't think there is a better experience then to sit and listen to a wonderfull sounding and looking set of speakers and know you did it all!

As a side note I would certainly play around with some of the recommendations Zilch has given. He has played with himself enough to have this down to pure science!:D

As pretty as your speakers look you owe it to yourself to have them sounding the very best they can and the guidance you receive from Zilch might be just the ticket.

Great thread!

Gary

Zilch
10-28-2006, 12:42 PM
He has played with himself enough to have this down to pure science!:D Admitedly, playing with L100s IS somewhat of a wank.

[At LEAST I'm not a "Basher," tho.... :p ]

Huynh Chau
11-07-2006, 07:50 AM
Has anyone here build their own L100 cabinets? Pls, give me cad raw and dimension of L100. Thank !

SEAWOLF97
11-07-2006, 08:12 AM
As for wood I would second the motion for MDF. It is better acoustically than particle board or plywood.
Widget

Had a JBL cinema Sub (China) that went TU. SAved the driver and busted up the box.
It wasnt even MDF , just kind of a laminated PAPER.

SEAWOLF97
11-07-2006, 08:30 AM
Has anyone here build their own L100 cabinets? Pls, give me cad raw and dimension of L100. Thank !

Chao Ong....Toi la nguoi My, nhung toi nho tieng VN. Ong viet tieng MY gioi lam, Ong o dau ? Vo toi co gia dinh gan Bien Hoa va Ho Nai. Toi co ban My o Da Lat va se tam Ong aye 2007.

loach71
11-07-2006, 09:25 AM
Chao Ong....Toi la nguoi My, nhung toi nho tieng VN. Ong viet tieng MY gioi lam, Ong o dau ? Vo toi co gia dinh gan Bien Hoa va Ho Nai. Toi co ban My o Da Lat va se tam Ong aye 2007.

I like Da Lat - nice cool mountain air!

Huynh Chau
11-08-2006, 02:52 AM
Chao Ong....Toi la nguoi My, nhung toi nho tieng VN. Ong viet tieng MY gioi lam, Ong o dau ? Vo toi co gia dinh gan Bien Hoa va Ho Nai. Toi co ban My o Da Lat va se tam Ong aye 2007.
Chào SEAWOLF97 ! Tôi là người Việt nam. Tôi biết nói tiếng Mỹ rất ít (I can speak a little English ). Tôi đang ở Hồ Chí Minh City. Khi nào Ông về Việt nam thăm Bạn Ông, Hy vọng được gặp Ông. Ông viết tiếng Việt Nam rất tốt, tôi rất khăm phục Ông, cám ơn Ông đă trả lời Tôi.
Good bye !

SEAWOLF97
11-08-2006, 09:32 AM
Chào SEAWOLF97 ! Tôi là người Việt nam. Tôi biết nói tiếng Mỹ rất ít (I can speak a little English ). Tôi đang ở Hồ Chí Minh City. Khi nào Ông về Việt nam thăm Bạn Ông, Hy vọng được gặp Ông. Ông viết tiếng Việt Nam rất tốt, tôi rất khăm phục Ông, cám ơn Ông đă trả lời Tôi.
Good bye !

khi nao chung toi di TPHCM, co nha khach gan cho Ben Thanh. Nam 2007 se di Da Nang (toi o DN 1969) va Can Tho (toi o CT 1970) va di Mui Ne mot lan nua. Mui Ne co bien dep nhut, va toi thich nhieu lam. Co mot ban My o Rach Gia va se di tam ong aye.

Toi da lam thong dich vien cho Hai Quan, nhung bay gio quen het roi !

Co le se gap ong nam 07

Chao ...Ong TOM

SEAWOLF97
11-08-2006, 09:34 AM
I like Da Lat - nice cool mountain air!

downright cold after HCMC . Looks like a French mountain village, but big money coming in there now. When were you there ?

Huynh Chau
11-17-2006, 08:24 AM
khi nao chung toi di TPHCM, co nha khach gan cho Ben Thanh. Nam 2007 se di Da Nang (toi o DN 1969) va Can Tho (toi o CT 1970) va di Mui Ne mot lan nua. Mui Ne co bien dep nhut, va toi thich nhieu lam. Co mot ban My o Rach Gia va se di tam ong aye.

Toi da lam thong dich vien cho Hai Quan, nhung bay gio quen het roi !

Co le se gap ong nam 07

Chao ...Ong TOM
OK! Hy vọng khi nào Ông thăm Việt Nam và HCMC tôi sẽ được gặp Ông, c̣n đây là bộ âm thanh mà tôi DIY:

Ralphh
03-12-2007, 05:53 PM
For those members who have requested my L-100 drawings, I have attached these. All dimensions were taken from a real L-100, and are the same except the overall cabinet depth, which I made 1/2" greater than the originals.

epoch5
03-12-2007, 06:18 PM
For those members who have requested my L-100 drawings, I have attached these. All dimensions were taken from a real L-100, and are the same except the overall cabinet depth, which I made 1/2" greater than the originals.

Hell of a job on the speakers and the drawings just might come in handy someday.:applaud:

Swerd
03-13-2007, 02:19 PM
For this project, I used a pair of original L100 crossovers. I tested the L-pads and found them both to be in good working condition. I then installed .01 by-pass caps. as others here have done.

My question, has anyone here replaced the original capacitors in their L100's with new main capacitors? If so, what type and brand did you use? What were the results of this change?

Also, has anyone modified their L100 crossovers to something a bit more complex, and with what result?I'm joining in on this thread kind of late, but it's never too late to compliment your excellent woodwork:applaud:. You got the walnut stain perfect.

I replaced the original JBL minimal crossovers in my L100As with a much better DIY design (http://audioheritage.org/vbulletin/showthread.php?t=13105). Your beautiful new cabinets deserve this treatment. With improved crossovers taming the upper midrange shrillness, and the ZilchPlugs™taming that midbass hump, you will get a full range flat frequency response from your L100s.

epoch5
03-13-2007, 03:41 PM
I'm joining in on this thread kind of late, but it's never too late to compliment your excellent woodwork:applaud:. You got the walnut stain perfect.

I replaced the original JBL minimal crossovers in my L100As with a much better DIY design (http://audioheritage.org/vbulletin/showthread.php?t=13105). Your beautiful new cabinets deserve this treatment. With improved crossovers taming the upper midrange shrillness, and the ZilchPlugs™taming that midbass hump, you will get a full range flat frequency response from your L100s.

I would like to try you crossovers some day but at my level of experience at this I would probably wind up doing more damage than good.:banghead:

Swerd
03-14-2007, 12:28 PM
I would like to try you crossovers some day but at my level of experience at this I would probably wind up doing more damage than good.:banghead:Of all the things I learned for DIY speaker building, probably the easiest for me was assembling and soldering crossover boards. Building a cabinet with tight fitting joints is still the hardest. Everyone comes with different skills and experience.

If you're interested, I'd be glad to help. Do you need detailed instructions, or hands on help? I'm located in Maryland, about 20 miles northwest of Washington, DC.

epoch5
03-14-2007, 05:39 PM
Of all the things I learned for DIY speaker building, probably the easiest for me was assembling and soldering crossover boards. Building a cabinet with tight fitting joints is still the hardest. Everyone comes with different skills and experience.

If you're interested, I'd be glad to help. Do you need detailed instructions, or hands on help? I'm located in Maryland, about 20 miles northwest of Washington, DC.

I think a good pic of the finished board would go along way. If there is one here I have missed it.:D

Swerd
03-15-2007, 08:22 AM
I think a good pic of the finished board would go along way. If there is one here I have missed it.:DI did take a picture of the board when I built it. I think it is still on my camera. I'll post that if I still have it, or work on a scale drawing. I also have a parts list. PM me if you want that.

I think I used a 10 x 7" piece of pegboard. If you remove the woofer, it easily fits in the bottom of the L-100 cabinet.

The caps and resistors can be arranged on the board any way you need.

I followed these general rules for laying out inductor coils (http://www.troelsgravesen.dk/coils.htm). Scroll down to the bottom and print the diagram. I keep a copy when I am working on a crossover board.

duaneage
03-15-2007, 09:57 AM
I make my own PCBs with copper boards and ferric chloride. Takes about an hour to make 2 high quality boards. I then mount the parts and paint clear lacquer to seal the copper traces, or I solder them completely.
I'm not a huge fan of terminal strips for anything other than testing.

epoch5
03-15-2007, 02:55 PM
I make my own PCBs with copper boards and ferric chloride. Takes about an hour to make 2 high quality boards. I then mount the parts and paint clear lacquer to seal the copper traces, or I solder them completely.
I'm not a huge fan of terminal strips for anything other than testing.

Making my own PCBs is way beyond me at this point.:banghead: maybe someday.

epoch5
03-15-2007, 02:57 PM
I did take a picture of the board when I built it. I think it is still on my camera. I'll post that if I still have it, or work on a scale drawing. I also have a parts list. PM me if you want that.

I think I used a 10 x 7" piece of pegboard. If you remove the woofer, it easily fits in the bottom of the L-100 cabinet.

The caps and resistors can be arranged on the board any way you need.

I followed these general rules for laying out inductor coils (http://www.troelsgravesen.dk/coils.htm). Scroll down to the bottom and print the diagram. I keep a copy when I am working on a crossover board.

Thanks for the inductor lesson. I hope you still have the pic.:D

Swerd
03-16-2007, 09:38 AM
Here is the parts list, and a hand drawn diagram that I used as a guide to assemble my crossover boards. I labled each part with the same ID number that appears in the parts list and in the schematic (http://audioheritage.org/vbulletin/showthread.php?t=13105) that I originally posted. I hope this helps. The arrows drawn through the inductors show the orientation of the hole (in the air core inductors), and in the steel laminate core where the steel bar runs.

Yes, I do have the photo on my camera. My home email set up is poor, so I scanned the drawing. I'll work on posting the photo.

The parts list shows two lists, with less expensive bipolar electrolytic caps used for the 2 largest caps shown on top, and with the somewhat more expensive Dayton metalized polypropylene (MPP) caps shown below. Take your pick, they should sound similar. I splurged and used the MPP caps.

I removed the woofer and disconnected the wires from its terminals. On my speakers, the woofer had similar spring-loaded connectors as on the back of the cabinet. I did not remove the midrange or tweeter, but instead cut the wires connecting them to the old crossover. I left those wires attached to the speakers as long as possible. I identified the plus wires by the 1.5 volt battery method as I described in my original post. I left the old crossover in place.

All the hookup wire I used was 16 gauge. Using larger gauge makes life very difficult during assembly and IMHO is not worth the trouble. JBL used even smaller wires than 16 g.

I also used a terminal strip on the board to help with all the connections, but this is not required.

epoch5
03-16-2007, 12:23 PM
Here is the parts list, and a hand drawn diagram that I used as a guide to assemble my crossover boards. I labled each part with the same ID number that appears in the parts list and in the schematic (http://audioheritage.org/vbulletin/showthread.php?t=13105) that I originally posted. I hope this helps. The arrows drawn through the inductors show the orientation of the hole (in the air core inductors), and in the steel laminate core where the steel bar runs.

Yes, I do have the photo on my camera. My home email set up is poor, so I scanned the drawing. I'll work on posting the photo.

The parts list shows two lists, with less expensive bipolar electrolytic caps used for the 2 largest caps shown on top, and with the somewhat more expensive Dayton metalized polypropylene (MPP) caps shown below. Take your pick, they should sound similar. I splurged and used the MPP caps.

I removed the woofer and disconnected the wires from its terminals. On my speakers, the woofer had similar spring-loaded connectors as on the back of the cabinet. I did not remove the midrange or tweeter, but instead cut the wires connecting them to the old crossover. I left those wires attached to the speakers as long as possible. I identified the plus wires by the 1.5 volt battery method as I described in my original post. I left the old crossover in place.

All the hookup wire I used was 16 gauge. Using larger gauge makes life very difficult during assembly and IMHO is not worth the trouble. JBL used even smaller wires than 16 g.

I also used a terminal strip on the board to help with all the connections, but this is not required.

Thanks I think my pea brain can follow your diagram.:applaud:

Lactuca
03-17-2007, 02:11 PM
For those members who have requested my L-100 drawings, I have attached these. All dimensions were taken from a real L-100, and are the same except the overall cabinet depth, which I made 1/2" greater than the originals.

:applaud: THANK YOU VERY MUCH!

jules_gerfault
03-09-2015, 04:19 PM
hi folks,

I apologize in advance for my poor english....

I own since 6 years a pair of JBL 4311wx-a. the speakers are le25, le5-2, and a 2213, special one, reconed with a 21005p, designed for 123a. but the result sounds good to me, as I haven't heard any other speaker, such as original 123a or 2213.

After many tries to find the best place in my living room, I found it. but it was very uncomfortable fore anything else than listening to music. I became resonable, and came back in a compromise situation: sound quite good, and easier living.

To fight this bommy bass, I started filling (half filling only) the ports with wrapped corrugated cardboard to reduce the diameter,and so lower the tuning frequency. The result is quite nice, but doesn't extend the bass response. But I haven't measured, so it's an "impression" only. For sure, bass is tighter, more precise.I really would like to try the zilch plugs, but it's impossible to find in France, and not very simple to import them from US or Canada. but, one day... I'm patient !!!

I'm also interested in build th improved crossover, but i'm afraid it didn't fit with the 2213 for the bass. Do you have any opinions about it ?

thanks and good night (it's 11 pm for me !!)