Next question on my L300-like enclosures and crossover networks

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

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Originally Posted by tjm001

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

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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.

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

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Originally Posted by Mannermusic

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

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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

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Originally Posted by tjm001

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

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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/vbullet...ht=cc+networks

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Originally Posted by Mannermusic

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/vbullet...ht=cc+networks

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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?

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Originally Posted by audiomagnate

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.

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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

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.

Thanks Barry - great info! We are at a crossroads with all this stuff disappearing. Can we still get the 2235H kits from JBL? Mike

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Originally Posted by tjm001

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

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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

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/OTk4WD..._id=880000500F
Pair JBL 2235H Bass Sub Woofer Speakers New Surrounds Tested 8 ohms Nice

Item price	$565.55
Quantity	1
Item number	291594735620
Shipping service	UPS Ground

Now I need to get going on those crossovers.

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

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Originally Posted by Doc Mark

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

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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

[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.