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View Full Version : Next question on my L300-like enclosures and crossover networks



tjm001
10-22-2015, 07:22 PM
As I have stated in a couple of previous posts I am building L300-like enclosures to house my LE15As, LE85s and 077/2405s. The unusual part of this project is the crossovers I plan to use. I have pairs of LX5s and N8000s. The LX5 which crosses over at 500HZ from the LE15A to the LE85 and the N8000 at 8000Hz from the LE85 to the 2405 tweeter. On the surface this sounds logical to me. And I hope it sounds good. We'll see. Maybe it's a dumb idea? Otherwise, I plan on some kind of custom crossover system that I hope you all can help me with.

But here's my current concern: Both the LX5s and the N8000 are really, really old. Not quite as old as me, but really old for millennium standards. They have not been hooked up to speakers for a long, long time. Should I risk hooking these up to my precious transducers? I do have training in electronics from many years ago, and my recollection is that capacitors don't do very well over that long a period of time. So my question is, what would you suggest I do? My experience at JBL repair facilities over the years has not been good. I'm afraid they may not know what I'm talking about. And my heath-kit oscilloscope and signal generator has long ago been discarded. So who could check these crossovers out before I hook them up? Thanks.

Tom

audiomagnate
10-23-2015, 12:59 AM
As I have stated in a couple of previous posts I am building L300-like enclosures to house my LE15As, LE85s and 077/2405s. The unusual part of this project is the crossovers I plan to use. I have pairs of LX5s and N8000s. The LX5 which crosses over at 500HZ from the LE15A to the LE85 and the N8000 at 8000Hz from the LE85 to the 2405 tweeter. On the surface this sounds logical to me. And I hope it sounds good. We'll see. Maybe it's a dumb idea? Otherwise, I plan on some kind of custom crossover system that I hope you all can help me with.

But here's my current concern: Both the LX5s and the N8000 are really, really old. Not quite as old as me, but really old for millennium standards. They have not been hooked up to speakers for a long, long time. Should I risk hooking these up to my precious transducers? I do have training in electronics from many years ago, and my recollection is that capacitors don't do very well over that long a period of time. So my question is, what would you suggest I do? My experience at JBL repair facilities over the years has not been good. I'm afraid they may not know what I'm talking about. And my heath-kit oscilloscope and signal generator has long ago been discarded. So who could check these crossovers out before I hook them up? Thanks.

Tom

This is not a good idea at all IMO. I'm tired and don't even know where to begin so I'll let other chime in.

Mannermusic
10-23-2015, 08:03 AM
If it were me, I'd retire/sell the LE15s, scrounge up a pair of 2235H and then do a full-up L300. Wire up the on-site crossover courtesy of Mr. Giskard. Done! Mike

tjm001
10-23-2015, 01:10 PM
If it were me, I'd retire/sell the LE15s, scrounge up a pair of 2235H and then do a full-up L300. Wire up the on-site crossover courtesy of Mr. Giskard. Done! Mike

I'm open minded on this project. My only goal is to put together something that sounds as good as (or better) than L300s. Please be more specific. You imply that LE15As are no good. You may very well be right. Tell me a little bit more as to why I should get rid of them and maybe I will. I am only considering using them because I have had them for a long time and they are in good condition after JBL re-coned them awhile back. I was of the impression they were great speakers. Maybe I'm wrong?

Also, are you saying a 2235H the same as a 136A?

I'm very interested in the crossover comment. Don't know who Mr. Giskard is? Tell me more. Thanks.

Tom

Mannermusic
10-23-2015, 01:57 PM
I'm open minded on this project. My only goal is to put together something that sounds as good as (or better) than L300s. Please be more specific. You imply that LE15As are no good. You may very well be right. Tell me a little bit more as to why I should get rid of them and maybe I will. I am only considering using them because I have had them for a long time and they are in good condition after JBL re-coned them awhile back. I was of the impression they were great speakers. Maybe I'm wrong?

Also, are you saying a 2235H the same as a 136A?

I'm very interested in the crossover comment. Don't know who Mr. Giskard is? Tell me more. Thanks.

Tom

Didn't mean to mislead. Yes, the 2235H is the newer replacement for the 136A. It is a better all around woofer than the LE15A. The LE15A is from the fifties and was the "top of the line" for years. Was used in the Paragon. I still use them, in fact, but there are no longer JBL recone kits available. But, the L300 is a significantly better sounding speaker than the older S7, which is what you have now. A major part of that improvement is a modern crossover by Greg Timbers (I believe). Also, it is "all-in-one" so you don't have to mess with separate crossover boxes which are prone to connection problems. Giskard is a JBL experienced guy here on the site who specializes in crossovers and has put together a DC biased crossover network ("charge coupled network") for us DIYers. A further improvement - quite a few folks here use it. You can look all that up with the Search engine here on site. So, if you move to the 2235H, you pick up all those potential advantages. Better woofer, better crossover, Greg Timbers/Giskard development expertise. However, you said the magic words, your LE15A's have fresh kits so they will still sound good (mine are 36 years old!) - it's all a matter of degree. We can get obsessed with this stuff! In fact, you could start with the S7 stuff and see what you think. The newer woofer and crossover are essentially "bolt-ins" especially since you are an electronics person. A nice upgrade package. Hope this clarifies! Hopefully others will chime in here. Mike

http://www.audioheritage.org/vbulletin/showthread.php?30051-Charge-Coupled-networks-for-L300-4333a&highlight=cc+networks

tjm001
10-23-2015, 04:13 PM
Didn't mean to mislead. Yes, the 2235H is the newer replacement for the 136A. It is a better all around woofer than the LE15A. The LE15A is from the fifties and was the "top of the line" for years. Was used in the Paragon. I still use them, in fact, but there are no longer JBL recone kits available. But, the L300 is a significantly better sounding speaker than the older S7, which is what you have now. A major part of that improvement is a modern crossover by Greg Timbers (I believe). Also, it is "all-in-one" so you don't have to mess with separate crossover boxes which are prone to connection problems. Giskard is a JBL experienced guy here on the site who specializes in crossovers and has put together a DC biased crossover network ("charge coupled network") for us DIYers. A further improvement - quite a few folks here use it. You can look all that up with the Search engine here on site. So, if you move to the 2235H, you pick up all those potential advantages. Better woofer, better crossover, Greg Timbers/Giskard development expertise. However, you said the magic words, your LE15A's have fresh kits so they will still sound good (mine are 36 years old!) - it's all a matter of degree. We can get obsessed with this stuff! In fact, you could start with the S7 stuff and see what you think. The newer woofer and crossover are essentially "bolt-ins" especially since you are an electronics person. A nice upgrade package. Hope this clarifies! Hopefully others will chime in here. Mike

http://www.audioheritage.org/vbulletin/showthread.php?30051-Charge-Coupled-networks-for-L300-4333a&highlight=cc+networks
I thank you Mannermusic for your very informative response. Since your initial post to my OP I have been researching 2235Hs and I have concluded that you are right on. The crossover comment really hit it off with me though. It brought back the memories of me hand winding enamel coated copper wire using an inductance bridge in the basement of the Chicago Air Route Traffic Control Center just before Reagan fired my ass after the PATCO strike in 1981. Crossovers are a real pain to build! So a ready to go "all-in-one" crossover intrigues me. Where can I sign up?

tjm001
10-23-2015, 04:57 PM
This is not a good idea at all IMO. I'm tired and don't even know where to begin so I'll let other chime in.

What part is not a good idea? The use of these transducers in a L300-like enclosure, or using the old LX5 and the N8000 crossovers? Or having the old crossovers checked out and/or repaired. Any opinions/input appreciated. Thanks.
Tom

1audiohack
10-24-2015, 10:06 AM
I have some information that may be of interest on the LE15 vs 2235 flavor conversation.

The following is an excerpt of an ongoing conversation with the mighty George Augspurger:

"As a follow-up to your questions about the Olympus and Apollo enclosures I have been working up some notes about the history of the S7 system, including the design of the LE15A. I will distribute the report in another week or so. The 2235 came later.

In the late 1960's, recording engineer Dave Hassinger introduced his "tight", "punchy", super-dry drum sound. At about that time, Bart Locanthi moved to Pioneer and developed a variant of the LE15A - the TL-1602.. A year or two later, to meet the demand for an even more rugged woofer, he designed the TL-1603. (I am not sure how the TL-1601 fits into the timeline.) The TL-1603 was, and continues to be, the most "bulletproof" 15-inch woofer of its kind. As an unforeseen bonus, it delivered a tighter bass sound than the LE15A family.

JBL Pro also felt the need for an upgrade to the LE15A. At my request, Ed May set to work on a new JBL woofer. First, he tested a variety of cone materials and settled on a very hard, stiff cone. Then, to get the right moving mass he added weight in the form of a copper ring attached to the voice coil tube. The result was the 2235. To my ears it may be the best-sounding 15-inch woofer ever made.. JBL Pro continues to supply replacement cone kits, but the cones are made by Hitachi, not Hawley. If Hitachi stops making the cones it is doubtful that anyone else will try to duplicate them."

There's more.

Barry.

Mannermusic
10-24-2015, 12:29 PM
Thanks Barry - great info! We are at a crossroads with all this stuff disappearing. Can we still get the 2235H kits from JBL? Mike

Doc Mark
10-24-2015, 01:02 PM
What part is not a good idea? The use of these transducers in a L300-like enclosure, or using the old LX5 and the N8000 crossovers? Or having the old crossovers checked out and/or repaired. Any opinions/input appreciated. Thanks.
Tom

Hi, Tom,

Just from my own experience, the 500HZ crossover is going to make the mid-horn more "honky" sounding, and to me ears, that was harsh and did not lend itself to long listening sessions. With a proper horn, the CD's seem to like 800HZ much better, or even 1,200 HZ, depending on the horn. I also like the 2235H better than the older LE15A. Just having the proper components is not enough to make your system the same as an L300, though. Lots of thought and planning went into the crossover design of the L300, and I think you'll find it much more detailed than the LXe and N8000 were/are. Just my opinion, but as I listen to L300's, with the 2235H woofers, every single day, I've had many years of effortless and sweet listening to back up my comments. I've also made lots of mistakes, and taken more than a few mis-steps in getting systems setup for our band, in the last 30 years, and my ears always told me when I'd done something that wasn't "good"! For what that is worth...... Take care, and God Bless!

Every Good Wish,
Doc

tjm001
10-25-2015, 12:12 PM
Well you guys convinced me on dumping my LE15As. Just got a pair on eBay!
Delivery package 1 of 1

Estimated delivery Thursday, Oct 29, 2015



https://ssli.ebayimg.com/00/s/OTk4WDE2MDA=/z/e7oAAOSwo6lWHG2k/$_1.JPG?set_id=880000500F
Pair JBL 2235H Bass Sub Woofer Speakers New Surrounds Tested 8 ohms Nice (http://www.ebay.com/itm/291594735620)



Item price
$565.55


Quantity
1


Item number
291594735620


Shipping service
UPS Ground

tjm001
10-25-2015, 12:15 PM
Now I need to get going on those crossovers.

Doc Mark
10-25-2015, 01:56 PM
Hey, Tjm001,

Well done on getting a pair of 2235H woofers! I predict that you're going to love them!! Are you going to cross them where the L300 does, at 800hz? That works fairly well with the longer horn, but not so well with the shorter version, it seems. Looks like you are well on your way to putting together a very nice JBL system, and I look forward to seeing the end results, and hearing your thoughts after you get to listen to your new system a bit! Have fun, and God Bless!

Every Good Wish,
Doc

tjm001
10-25-2015, 02:20 PM
Hey, Tjm001,

Well done on getting a pair of 2235H woofers! I predict that you're going to love them!! Are you going to cross them where the L300 does, at 800hz? That works fairly well with the longer horn, but not so well with the shorter version, it seems. Looks like you are well on your way to putting together a very nice JBL system, and I look forward to seeing the end results, and hearing your thoughts after you get to listen to your new system a bit! Have fun, and God Bless!

Every Good Wish,
Doc

Thanks Doc! I have and was planning to use the longer H92 horn. I got it a few months ago also on Ebay. I was planning on crossing them at 800hz or whatever the enhanced crossover that Mannermusic mentioned previously does it at if different. My assumption is that this is indeed at 800hz or slightly higher.

As I stated in my last post getting the best crossover for this combination is now my top priority. I hope to find one already built, but will reluctantly build it myself if there is no other way. I'm fascinated by the Timbers/Giskard crossover that Mannermusic describes. I'm avidly searching for as much information I can on this. Thaks again.

Tom

1audiohack
10-25-2015, 03:22 PM
[QUOTE=tjm001;382025]Well you guys convinced me on dumping my LE15As. [QUOTE]

That was not my intent. Some people really like that driver and as you must know, in good condition they are fairly valuable.

Barry.

tjm001
10-25-2015, 03:54 PM
[QUOTE=tjm001;382025]Well you guys convinced me on dumping my LE15As. [QUOTE]

That was not my intent. Some people really like that driver and as you must know, in good condition they are fairly valuable.

Barry.

Man I know that! Please don't feel that you forced me into it. Your information was extremely credible and accurate. Furthermore, I had the privilege of personally discussing the attributes of my LE15As with Mr. Augspurger sometime back in the late 70's or early 80's. I have great respect for the man's knowledge and experience. I have known of him for many years. I got started in this stuff back in 1959. It was his quotes you presented that convinced me the 2235H was the best driver for this project.

Some lucky person will soon own my beloved LE15As soon. I've had them since 1965. Thanks


PS I apologize for using the term "dumped my LE15As"! I'm not a politically correct type of guy. I should have said I'm replacing them with ...because...

Mr. Widget
10-25-2015, 04:03 PM
Some people really like that driver and as you must know, in good condition they are fairly valuable.I have owned a number of systems with LE15A woofers over the years as well as a few systems with 2235Hs too. I like them both… if I was going to buy either in the future I would probably go with the older LE15A woofers, but that maybe more out of nostalgia than the actual sonic quality of the different woofers.

Since the goal is to create something similar to an L300, then I absolutely would use the 2235Hs with H92 horns, LE85s, and either 2405 or 077 tweeters. I would also use the charge coupled crossover networks that our forum member Giskard so generously posted on this forum years ago. Of course there is also the Pass network as well… but I think I would go with the more traditional JBL design.


Widget

tjm001
10-25-2015, 05:23 PM
OK. Thanks for all of the great discourse so far. I really feel good about the direction of this project. Reiterating, the project is to construct a system that looks like a L300 Summit and sounds just as good or better. The components thus far are to be 2235Hs, LE85s with H92 horns with lenses, 2405s and a charge coupled crossover network that forum member Giskard posted on this forum years ago. I have most of the details except the crossover details. If someone already has or can make a pair of these crossovers to sell or make for me I would like to hear from them. I think there is a good possibility that I could make them myself if someone can provide me with enough detailed information. So far the closest to that seems to be
http://audioheritage.org/vbulletin/showthread.php?166-4333-S300-L300-equivalent-bandbass-circuit&p=1042#post1042 Please let me know if this is correct.

Meanwhile, I have two baffle boards with two 4 inch holes for vents for the LE15As instead of the original one 4 inch hole for the original 136A configuration. I did this after recent posts about modifying them to accommodate the LE15As instead of the 136A configuration. But according to https://www.jblpro.com/pub/manuals/enclgde.pdf the 2235H uses the same porting as the LE15A! Which is different than the original 136A porting. In other words the two 4 inch recently cut holes for the LE15As are also the requirements for the 2235H too! WHAT DO YOU THINK OF THAT? Do you concur with the data in https://www.jblpro.com/pub/manuals/enclgde.pdf ?
What is the technically correct answer? Thanks.
Tom

1audiohack
10-25-2015, 06:08 PM
That really depends on how loud you intend to listen. A saturated port is not only noisy but acts like a leaky box, not a resonator so pro boxes are ported large enough to never loose control of the woofer(s).

Port(s) can be so large as to not load the driver at all at small signal levels.

I bought a VI box and a lab grade inductive current meter that connects to an O scope as to be able to measure impedance at well over 2kW and what an education that was!

Shooting from the hip I would port it like the 4430.

Barry.

tjm001
10-25-2015, 06:26 PM
That really depends on how loud you intend to listen. A saturated port is not only noisy but acts like a leaky box, not a resonator so pro boxes are ported large enough to never loose control of the woofer(s).

Port(s) can be so large as to not load the driver at all at small signal levels.

I bought a VI box and a lab grade inductive current meter that connects to an O scope as to be able to measure impedance at well over 2kW and what an education that was!

Shooting from the hip I would port it like the 4430.

Barry.

That's my instinct too. In other words stick with the 2 holes?
Tom

1audiohack
10-25-2015, 07:32 PM
It's been so long since I had the grilles off them that I don't recall for sure what the port diameter is, I don't think they are 4" though. I will look Tuesday when I am back at the shop if someone else doesn't chime in first.

Barry.

grumpy
10-25-2015, 07:52 PM
4" x 8.25" deep

1audiohack
10-25-2015, 09:04 PM
And there you have it!

Thanks Grumpy, I hope all is well with you.

Barry.

grumpy
10-25-2015, 09:44 PM
Doin' great, thanks. Need more quality playtime!

4313B
10-26-2015, 07:02 AM
I think some model numbers might have gotten got mixed up in a post or two above (easy to do all these years later). The 2235H (Greg Timbers - 1980) came after the 136H/2231H (Mark Gander - 1979). Perhaps someone meant the 136A/2231A?


Meanwhile, I have two baffle boards with two 4 inch holes for vents for the LE15As instead of the original one 4 inch hole for the original 136A configuration. I did this after recent posts about modifying them to accommodate the LE15As instead of the 136A configuration. But according to https://www.jblpro.com/pub/manuals/enclgde.pdf the 2235H uses the same porting as the LE15A! Which is different than the original 136A porting. In other words the two 4 inch recently cut holes for the LE15As are also the requirements for the 2235H too! WHAT DO YOU THINK OF THAT? Do you concur with the data in https://www.jblpro.com/pub/manuals/enclgde.pdf ?
What is the technically correct answer? Thanks.The 136/2231 was "too overdamped" with a very low Fs, a very high compliance and a suggested tuning frequency around 26 Hz. However, in practice JBL usually tuned it up to around 30 Hz in the 43xx monitors as well as the L300 (they also suggested running a 30 Hz high pass filter with all their large format 43xx monitors).

The LE15A also had a high compliance but with a higher Fs and JBL usually tuned it up much higher, around 38 Hz.

The 2235H, arguably the best of the bunch, is arguably best tuned to around 30 Hz, although JBL did tune it to 34 Hz using the dual 4-inch ports in the 4430. Drew Daniels referred to that particular tuning of the 4430 as "aggressive". My personal pair of 4430's (2235H) were tuned to 29 Hz using a single 4-inch port and that worked well for me personally.

Note that the tuning frequency isn't exact. I measured several L300's, 4331's, 4333's and 4343's back in the day and they varied around 28 Hz to 32 Hz depending on humidity, temperature, etc. In practice, that tuning frequency range works well for the 136A/2231A, 136H/2231H and the 2235H.

4313B
10-26-2015, 07:38 AM
Shooting from the hip I would port it like the 4430.

4" x 8.25" deep

And that would yield a highly successful result. :)
5 cubic foot volume with two 4-inch diameter ports having 8-1/4" ducts.

tjm001
10-26-2015, 11:27 AM
And that would yield a highly successful result. :)
5 cubic foot volume with two 4-inch diameter ports having 8-1/4" ducts.

Outstanding! I don't have to plug up the hole or make new baffles. Thanks.

Tom

tjm001
10-27-2015, 12:21 PM
I would also use the charge coupled crossover networks that our forum member Giskard so generously posted on this forum years ago. Of course there is also the Pass network as well… but I think I would go with the more traditional JBL design.


Widget

I'm still quite uncertain on how to obtain or build the crossovers for this project. I have seen various references to the charge coupled "Giskard" type crossovers, but have not yet been able to locate the most current version that applies to this specific situation. Can anyone point me in the right direction please.

Also, is the "Pass network" that Mr. Widget mentioned the one in this link? http://www.firstwatt.com/pdf/art_l300.pdf
Thanks.

Tom

pauly
10-27-2015, 05:37 PM
G'day Tom,

Yes - that's the one - I'm just completing the Pass crossovers myself, and it's been a fun (& expensive) exercise so far! I now have the boards loaded, and lpad mountings constructed. My daughter and I are wiring up the boards tonight and I may fit them all this weekend.

I chose the Pass crossovers as his writeup and rationale for the changes seemed sensible to me. Also his reputation amongst the users of this forum is sound. Also, the circuit (asides from the single cap on the tweeter) is very close to the original crossovers with slightly different crossover points.

Thanks
Pauly



I'm still quite uncertain on how to obtain or build the crossovers for this project. I have seen various references to the charge coupled "Giskard" type crossovers, but have not yet been able to locate the most current version that applies to this specific situation. Can anyone point me in the right direction please.

Also, is the "Pass network" that Mr. Widget mentioned the one in this link? http://www.firstwatt.com/pdf/art_l300.pdf
Thanks.

Tom

tjm001
10-27-2015, 05:55 PM
G'day Tom,

Yes - that's the one - I'm just completing the Pass crossovers myself, and it's been a fun (& expensive) exercise so far! I now have the boards loaded, and lpad mountings constructed. My daughter and I are wiring up the boards tonight and I may fit them all this weekend.

I chose the Pass crossovers as his writeup and rationale for the changes seemed sensible to me. Also his reputation amongst the users of this forum is sound. Also, the circuit (asides from the single cap on the tweeter) is very close to the original crossovers with slightly different crossover points.

Thanks
Pauly

Please let me know how this works out.

tjm001
10-31-2015, 01:56 PM
I was so glad I didn't have to make new baffle boards for my 2235Hs since they port the same as the originally intended LE15As. Guess what! The hole diameter for the 2235H is smaller than the hole for the LE15A. The holes were just too big for the newly acquired 2235Hs. So that's what I've been up to the last few days.

But the good news is they are actually starting to kind of look like L300s. I'm now in the process of making the front baffles nice and smooth to accommodate some nice semi-flat black paint. Still a long way to go.

Tom679726797367974

pauly
11-01-2015, 04:40 AM
Gday tom,

Well, all done - and a very pleasing result. I've posted some comments in the thread I started on the crossovers here;

http://www.audioheritage.org/vbulletin/showthread.php?37411-Your-opinion-on-4333-crossover-please

Thanks
pauly


Please let me know how this works out.

tjm001
11-01-2015, 08:35 AM
Gday tom,

Well, all done - and a very pleasing result. I've posted some comments in the thread I started on the crossovers here;

http://www.audioheritage.org/vbulletin/showthread.php?37411-Your-opinion-on-4333-crossover-please

Thanks
pauly

Thanks Pauly. I'm leaning in the same direction for my L300-like system. At least to start with. I can always go with the bi-amp type stuff later.

I'm asking for input as to the best place(s) to buy the components for building these crossovers please. I see that Parts Express seems to be mentioned often in this forum. Also, looking for ideas as to what to use (and where to get them) for input connectors on the back panels of my enclosures. Thanks all.

Tom

Mr. Widget
11-01-2015, 10:15 AM
Looking really good! As for where to get parts, I've had very good results with Parts Express. For the rear terminal panel, I usually use 1/4" black acrylic sheet or black painted tempered Masonite.


Widget

tjm001
11-01-2015, 01:32 PM
Looking really good! As for where to get parts, I've had very good results with Parts Express. For the rear terminal panel, I usually use 1/4" black acrylic sheet or black painted tempered Masonite.


Widget

Thank you. Do you or anyone know the details of the binding posts on the L300? I've never seen a L300 up close to know those details. Best I have figured so for is that the originals were made by Cardas. But what model (or other make equivalent) I don't know. How do they connect to the amp? Are those RCA jacks, spring clamping, screw on, etc.? Thanks.

Tom

Mr. Widget
11-01-2015, 04:07 PM
JBL's original terminals were poorly designed spring clamps. I'd suggest you use good quality "five-way" binding posts. You can buy name brand posts if you like, I wouldn't spend the money on them. Hell, I will pay for them myself if you can actually prove you can hear a difference in an objective test. ;)


Widget

donsof
11-02-2015, 11:53 AM
Hi
I have ran into the woofer bore issue myself, and consider the JBL fork clamps to be a great fix.
They allow quick removal of the driver and allow you to rotate them.
The original 136A woofer required a minimum bore of 13.96-14.0" inches.
JBL couldn't open the Dia. up too far, or the T nuts have nothing to grab onto.

Last night, while trying to test a LE15 woofer in my L300, I had to do this:
I used some .19" thick cork, and shimmed the woofer out with it.
Any thinner than .19 thick, and its not going to be enough.

On my baby L300 (a C36 with LE15s & LE85s) I use the fork clamps, which are on a 11.65-11.7" square bolt pattern, with 1/4 inch T nuts and screws. No cork required as that woofer bore is 14.2 Dia
Those can be found on e-b-a-y

Also on your port dimension, my L300 original port is 4.18" DIA x 4.3" long

I could ramble on about my own woofer testing for hours, but a good aftermarket 2235 recone, in a 2231 alinco frame, sounds as good as a reconed LE15, and a NOS 2235H ferrite. I have found the woofers need to be fresh, and the spiders get bad just as the foam does.

LINK TO PICTURES
http://jpegbay.com/gallery/004766188-.html#1

Don

tjm001
11-02-2015, 01:58 PM
Thanks for the good information Don. I appreciate it!

Tom

tjm001
11-02-2015, 02:15 PM
Just wondering if there is any bracing on the rather heavy horn and driver assembly in a L300, or does it just hang on by the flange of the horn on the baffle? Thanks.

Tom

Mr. Widget
11-02-2015, 07:29 PM
Just wondering if there is any bracing on the rather heavy horn and driver assembly in a L300, or does it just hang on by the flange of the horn on the baffle? Thanks.
I do not know the answer, but I do know that JBL did use a metal brace on the L200 with the same driver and shorter horn. Therefore I would guess that they must have and if not, then they should have.


Widget

Doc Mark
11-02-2015, 07:36 PM
Evening, Tom,

My L300's are braced, but in a way that makes me wonder if JBL did it, or a previous owner. Here is what holds our LE85 in place in our L300's. It's mounted in the removable access plate, and slides around the circumference of the driver nicely.

68047

68048

68049

68050

68051

Every Good Wish,
Doc

Doc Mark
11-02-2015, 07:41 PM
....and here's the last photo, showing how the Le85 driver is "right there, and nestles neatly into the wooden brace setup, as the access door is slid into place, and screwed tight.

68052 And, a measurement that I forgot to post last night:

68054

After looking at mine again, I do believe that they were created by some former owner. But, they work nicely, and it's a great idea. In any case, I do hope that this info gives you a few ideas of your own. Good luck, and God Bless!

Every Good Wish, Doc

P.S. If you need better photos, please let me know, as I took these with a point-and-shoot camera, and now can take them again, with a big Nikon, with good lighting.

tjm001
11-03-2015, 06:29 AM
Thanks Doc and Widget. Just the info I needed! Greatly appreciated.

Tom

Doc Mark
11-03-2015, 08:44 AM
Morning, Tom,

You are most welcome, Sir, and I'm glad that info was helpful in your project plans. Looking in the JBL Library, you might check out this photo of the L300 Summit, in cut-away, as it does not appear that the LE85 had the support that mine has.

http://www.lansingheritage.org/images/jbl/specs/home-speakers/1975-l300/page3.jpg

However, you could very easily cobble something like that together, and make it work, just like it does in our L300's. I look forward to seeing what you decide to do! Talk later, and God Bless!

Every Good Wish,
Doc

tjm001
11-03-2015, 09:05 AM
Morning, Tom,

You are most welcome, Sir, and I'm glad that info was helpful in your project plans. Looking in the JBL Library, you might check out this photo of the L300 Summit, in cut-away, as it does not appear that the LE85 had the support that mine has.

http://www.lansingheritage.org/images/jbl/specs/home-speakers/1975-l300/page3.jpg

However, you could very easily cobble something like that together, and make it work, just like it does in our L300's. I look forward to seeing what you decide to do! Talk later, and God Bless!

Every Good Wish,
Doc

Thanks Doc. Actually that drawing has been pretty much been my primary guide for most of the layout. I started out with the known exterior dimensions and then did a proportion using that drawing. I'll not be working on the project for a week or so as we are about to leave to visit grand-kids in MI and WI. Later.

Tom

Doc Mark
11-03-2015, 09:14 AM
Hey, Tom,

Have a safe trip, and enjoy being with your Grandkids! Take care, and God Bless!

Every Good Wish,
Doc

Sepperl
11-04-2015, 06:09 AM
68056
Thanks Doc and Widget. Just the info I needed! Greatly appreciated.

Tom
http://www.audioheritage.org/photopost/data//500/thumbs/DSC02016.JPG

Doc Mark
11-04-2015, 09:59 AM
Hi, Sepperl,

Excellent photo! Were your L300's setup that way when you bought them? You didn't, by any chance, buy them brand new, did you??! Your LE85 support looks identical to mine, so I'm thinking that maybe this support WAS originally used by JBL, or was at least used sometime during the run of those excellent speakers. I wonder if Greg Timbers could share his thoughts on that? I had his contact info at one time, but cannot lay hands on it right now. If anyone can send him a note about this, including a link to these photos, it would be wonderful to read what me might remember about this setup. Thanks for sharing your photos, and God Bless!

Every Good Wish,
Doc

donsof
11-07-2015, 03:20 PM
My L300 has the support on the rear door as well. It looks factory made to me.

While we are on the subject of L300's and drivers, can anyone recommend the best source for new cones to drop into the 2235 / 2231 / 136A woofer?
Or can anyone tell me how many companies are making the voice coil and cone paper now?
I know there are many examples on fleabay, and I would like to get a pre-glued drop in kit.

I have a shot 2231 that needs a new 8 ohm cone.
I think I could handle a drop in kit, but I am not so comfortable with a kit needing all components glued together.
If the glue together kit is the best option, I will send it off to a good service guy.
I know we all want NOS JBL 2235 cones, but I am growing impatient, waiting on one for less than 150$
My 136A woofer needs a new surround, right now, so I plan on ordering parts this week.

I have a local recone guy that I may just go back to, if the unbuilt kit is best.

Don

1audiohack
11-08-2015, 10:13 PM
While we are on the subject of L300's and drivers, can anyone recommend the best source for new cones to drop into the 2235 / 2231 / 136A woofer?

Or can anyone tell me how many companies are making the voice coil and cone paper...

I know we all want NOS JBL 2235 cones, but I am growing impatient, waiting on one for less than 150$
Don

Funny how we get it in our head what something is worth to us, I do it too.

While there are several JBL 15's that use the same cone made by Hawly with varying coils, spiders and surrounds to make various kits, the 2234-2235 (tel:2234-2235) cone kit uses a cone made by Hitatchi that is pretty hard. This is a big part of the voice of a 2235 and a generic kit wont sound the same.

I was running part numbers last week and there is currently more than 100 C8R2235 kits in stock.

Still no C8R2245's. :(

I would buy the genuine kit and make it right while you still can. Lot's of kit numbers have gone obsolete in the last year.

Barry.

JeffW
11-09-2015, 07:42 AM
I would buy the genuine kit and make it right while you still can. Lot's of kit numbers have gone obsolete in the last year.

Barry.

Then there's the age old dilemma of the kits not being sold to the general public. If his local recone guy is an authorized JBL service facility, he's set. And if he's looking for one for $150 or less, aftermarket are going to be his only choice. I haven't looked in a while, but I'd be amazed if the genuine 2235 kit is less than $250 ea.

Ian Mackenzie
11-09-2015, 08:56 AM
I have some information that may be of interest on the LE15 vs 2235 flavor conversation.

The following is an excerpt of an ongoing conversation with the mighty George Augspurger:

"As a follow-up to your questions about the Olympus and Apollo enclosures I have been working up some notes about the history of the S7 system, including the design of the LE15A. I will distribute the report in another week or so. The 2235 came later.

In the late 1960's, recording engineer Dave Hassinger introduced his "tight", "punchy", super-dry drum sound. At about that time, Bart Locanthi moved to Pioneer and developed a variant of the LE15A - the TL-1602.. A year or two later, to meet the demand for an even more rugged woofer, he designed the TL-1603. (I am not sure how the TL-1601 fits into the timeline.) The TL-1603 was, and continues to be, the most "bulletproof" 15-inch woofer of its kind. As an unforeseen bonus, it delivered a tighter bass sound than the LE15A family.

JBL Pro also felt the need for an upgrade to the LE15A. At my request, Ed May set to work on a new JBL woofer. First, he tested a variety of cone materials and settled on a very hard, stiff cone. Then, to get the right moving mass he added weight in the form of a copper ring attached to the voice coil tube. The result was the 2235. To my ears it may be the best-sounding 15-inch woofer ever made.. JBL Pro continues to supply replacement cone kits, but the cones are made by Hitachi, not Hawley. If Hitachi stops making the cones it is doubtful that anyone else will try to duplicate them."

There's more.

Barry.




I think the 2231A came before the 2235H that was due to the embargo on alnico. As l recall there may have been a 2231H as l bought some of those drivers in the period.

The mass control ring enabled deeper bass in a smaller box than the LE15 but the reality was and still is that the mass control ring impacts on the mid range performance of that woofer.

Remove the mass control ring and you have the 2234H as used in the 4435. The 4430 used the 2235H

If you have ever compared the two systems the 2234H has a much improved clarity in the midrange and is faster on transients. Simply a reality of he lighter cone.

Therefore, if you are looking a squeeze some performance out of the project the ever so important midrange the 2234 recone kit is an interesting option. With some careful retuning and modest boost at system resonance it would a kick arse system.

1audiohack
11-09-2015, 09:41 AM
Right on all accounts guys.

The point I wanted to make is that there are several JBL Pro 15"s that the quality aftermarket kits wouldn't have a significant sonic impact on, the 2234-2235 is not one of them, it's voice is unique.

Barry.

donsof
11-16-2015, 11:28 AM
thanks 1audiohack

So where do I go to buy 1 of the C8R2235 kits?
Or what service center do I see?
I was shopping on flea-bay, and also calling several JBL dealers.
Some of the authorized reconers say the 2235 kit is unavailable?
Which dealer or dealers have this many cones?

I bought several NOS 2215 kits lately, for LE-15 projects, and that took some waiting.
The new kits have little serial number tags on them.
Is there a way to date the kit from those numbers?

thanks Don

tjm001
11-16-2015, 01:35 PM
I'm trying to keep my original post on topic in order to get information on my longstanding and complex L300-like project. Thank you.

Tom

tjm001
11-18-2015, 10:30 AM
I'm slowly progressing. New questions keep popping up. I was thinking of making the backs removable just in case I want to make interior modifications later. I never did see a L300 other than pictures of one. Is the back removable or is it permanently glued and therefore permanently sealed? Any thoughts on this? Thanks.

Tom
68262

Doc Mark
11-18-2015, 10:51 AM
Hi, Tom,

Lovely work! The backs are sealed, with that small access panel where the CD is cradled, as shown in some previous photos. Have fun, and I look forward to seeing how your project turns out! Take care, and God Bless!

Every Good Wish,
Doc

macaroonie
11-18-2015, 11:49 AM
Nice work with your veneers there Tim. Looks like you are nearing the home straight with a winner.

One suggestion , don't muck around with the foam under the glass on the top , just get 10mm glass with a micro bevel on the edges and make your solid trims such that it all fits nice and even.
Paint the wood underneath black same as the front and back.

Some of this might help you

http://www.audioheritage.org/vbulletin/showthread.php?17238-Backyard-Box-Building-The-Build&p=184061&viewfull=1#post184061

68270

68271

tjm001
11-18-2015, 08:10 PM
Nice work with your veneers there Tim. Looks like you are nearing the home straight with a winner.

One suggestion , don't muck around with the foam under the glass on the top , just get 10mm glass with a micro bevel on the edges and make your solid trims such that it all fits nice and even.
Paint the wood underneath black same as the front and back.

Some of this might help you

http://www.audioheritage.org/vbulletin/showthread.php?17238-Backyard-Box-Building-The-Build&p=184061&viewfull=1#post184061

Thanks Macaroonie. I've seen your previous posts with great interest. We seem to have a similar motivation. I too have long had the JBL bug since hearing the Paragon back in around 1965 or 1966 when I was a young Airman stationed in Washington, DC. That's when I bought the LE15As and LE85s that I was to use in this project which has had a long time coming. Thanks to good advice from this forum I have replaced the LE15As with 2235Hs and added a couple of 2405s to go with my original LE85s which have new aluminum diaphragms. Thanks for your input. Thanks also to Doc and others that have helped me so far.

Tom

tjm001
11-20-2015, 02:58 PM
Previous posts have shown the 2 horizontal braces going from front to back paralleling the horn. They appear to be about 2x4in size. Also, there is the cradle type thing holding the LE85 attached to the back door. Since I'm getting close to closing up the enclosures I want to make sure I am not missing anything. Anybody know if I am missing any bracing other than mentioned above?

Also I'm looking for some details for building the grill. If anyone can give me measurements or closeup photos of the L300 grill construction I would appreciate it. Thanks.

Attached is a view of the counterfeit L300 production line in Potomac Falls, VA.:D68297

tjm001
11-25-2015, 06:06 PM
As you can see they are beginning to look like L300s. I sprayed on some Sherwin-Williams dull rubbed effect pre-cat lacquer with some black pigment added last night and I'm happy with the satin like finish results.

I have all the components for a Nelson Pass type crossover, but was wondering what the exact distance is between the knobs of the Lpads on a real L300 before I drill more holes in the finished baffle board. Thanks for any information on this.

Member Mike Botts is helping me out with the dimensions and construction of the grills.

Tom68367

Challenger604
11-25-2015, 09:22 PM
As you can see they are beginning to look like L300s. I sprayed on some Sherwin-Williams dull rubbed effect pre-cat lacquer with some black pigment added last night and I'm happy with the satin like finish results.

I have all the components for a Nelson Pass type crossover, but was wondering what the exact distance is between the knobs of the Lpads on a real L300 before I drill more holes in the finished baffle board. Thanks for any information on this.

Member Mike Botts is helping me out with the dimensions and construction of the grills.

Tom68367


Very nice job Tom!
can't wait to see the finished pair!
C

Alobar
11-26-2015, 01:32 AM
Previous posts have shown the 2 horizontal braces going from front to back paralleling the horn. They appear to be about 2x4in size. Also, there is the cradle type thing holding the LE85 attached to the back door. Since I'm getting close to closing up the enclosures I want to make sure I am not missing anything. Anybody know if I am missing any bracing other than mentioned above?

Also I'm looking for some details for building the grill. If anyone can give me measurements or closeup photos of the L300 grill construction I would appreciate it. Thanks.

Attached is a view of the counterfeit L300 production line in Potomac Falls, VA.:D68297 I am so impressed with your woodworking skills as well as everything else you are putting into this great speaker design. These are going to be L300's in every respect, the real deal!

macaroonie
11-29-2015, 03:36 AM
68367[/QUOTE]

Looking really good. Just be careful moving them about , don't want any dings.

tjm001
11-29-2015, 07:56 AM
Thanks. Its been a lot more involved than I thought it would be. But that's the way it always is!

Still need the distance between the Lpad shafts from a real L300 owner please.

Thanks.

Tom

Bluegrassmaven
11-29-2015, 06:07 PM
They are 2.25 inches center to center

tjm001
11-29-2015, 06:56 PM
They are 2.25 inches center to center

Thank you!

Tom

tjm001
12-12-2015, 01:58 PM
I'm getting closer, Need some kind of JBL foilcal for the Lpad controls. It does not need a serial number. Just something that looks like the original with the numbers around the knobs and the JBL colors and logo. Surely someone other the Sign Shop guy must do things like this? Any ideas? Thanks.

Tom68709

Alobar
12-12-2015, 04:11 PM
WOW!! :bouncy:

macaroonie
12-12-2015, 07:05 PM
^ Beautiful.

Doc Mark
12-12-2015, 07:25 PM
Good Evening, Tom,

WOW!! You've done a stellar job in crafting your L300 clones, Sir!! Lovely work, and a great JBL model!! Though experimenting with a 4-way of JBL goodies, similar to a 4345, we still love listening to our L300's every single day, and at night when we watch movies with the sound run through the L300's! Again, well done, and a big tip'o-the hat to you, Sir!! Take care, and God Bless!

Every Good Wish,
Doc

Challenger604
12-13-2015, 07:52 AM
GORGEOUS!
Bravo!

tjm001
12-14-2015, 08:08 PM
Tomorrow (Tuesday) is the first test to see if they make any noise. I'm kind of nervous about it. It's been about 40 years since I did any soldering of electronic circuits. They are really fricking heavy! And that's without the 2235Hs installed yet. Will transfer them down to my man cave in the morning for the big test. If you never hear from me again...well, you know what.

Tom

Alobar
12-14-2015, 08:37 PM
There is nothing quite like building something yourself. I never have built a speaker enclosure before but I have done other projects that brought me great pleasure, especially once finished and first used. Exciting times.. Enjoy! :applaud:

tjm001
12-16-2015, 10:30 AM
Tomorrow (Tuesday) is the first test to see if they make any noise. I'm kind of nervous about it...

Tom

Overall they sound awesome! Testing them right now. Only issue is one of the 2405s probably needs a new diaphragm. That's no big surprise as a bought them on eBay a few years ago and never had them tested.

Otherwise thanks for all the help. If anyone else wants to do this I'd be glad to help them in the process. Just PM me.

Tom68798

Alobar
12-16-2015, 10:38 AM
I thought I heard thunder off to the southeast!:D
Great job, they are awesome.