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Doc Mark
08-11-2008, 07:25 PM
Evening, Friends,

Today, I took one of my two 2405's down to the hardware store, to get a couple of machine screws for it, when I noticed that one of the mounting holes was actually stripped out! Darn it! After some consideration, I realized that it had been that way when I had purchased it, many years ago. Oops! Two questions, please:

- Is the mounting plate for the 2405 still available from JBL?

- Can you point me to the info here on LH forums that will help me build the lastest-greatest 10K crossover for these drivers? I tried to do a search for such info, to no avail.

Thanks, very much, and God Bless!

Every Good Wish,
Doc

John
08-11-2008, 07:30 PM
Evening, Friends,

Today, I took one of my two 2405's down to the hardware store, to get a couple of machine screws for it, when I noticed that one of the mounting holes was actually stripped out! Darn it! After some consideration, I realized that it had been that way when I had purchased it, many years ago. Oops! Two questions, please:

- Is the mounting plate for the 2405 still available from JBL?

- Can you point me to the info here on LH forums that will help me build the lastest-greatest 10K crossover for these drivers? I tried to do a search for such info, to no avail.

Thanks, very much, and God Bless!

Every Good Wish,
Doc

You want to talk to Mike Caldwell. He had a bunch of them.:bouncy:

Or fill it with some epoxy putty and retap, tighten it up just to take out the slack as the other 3 will hold it down to the baffle even without the 4th. screw.

hjames
08-11-2008, 07:37 PM
Probably want to build a pair of Giskard's 3133 Equivalent circuits - its what I have in my L200 cabinet based 3ways, and what I used to have in the DIY 3ways in my old 4320 cabinets .. Its not Charge Coupled, but its a nice circuit and sounds good.
see
http://audioheritage.org/vbulletin/showpost.php?p=1042&postcount=3

They are designed for 4333B systems, but seemed to work well in my short-horn 3ways

Anyway - here's what I'm running them with ...
2235 15" woofer
2420 MF driver with 2307 Horn and 2308 lens
2405 HF driver (new to unit)
3133B equiv crossover networks
http://audioheritage.org/vbulletin/showpost.php?p=105770&postcount=22

Hope it helps!


Evening, Friends,

Today, I took one of my two 2405's down to the hardware store, to get a couple of machine screws for it, when I noticed that one of the mounting holes was actually stripped out! Darn it! After some consideration, I realized that it had been that way when I had purchased it, many years ago. Oops! Two questions, please:

- Is the mounting plate for the 2405 still available from JBL?

- Can you point me to the info here on LH forums that will help me build the lastest-greatest 10K crossover for these drivers? I tried to do a search for such info, to no avail.

Thanks, very much, and God Bless!

Every Good Wish,
Doc

grumpy
08-11-2008, 07:44 PM
... or use one longer machine screw and a nut/washer/lockwasher .

Might help keep you from accidentally dropping the driver inside the cabinet:)

Robh3606
08-11-2008, 08:28 PM
Just retap them up to the next size or a metric size if the jump is too big.

Rob:)

bigyank
08-12-2008, 04:34 AM
http://shop.ebay.com/items/_W0QQ_fromZR46?_nkw=jbl+2402&_fromfsb=0&_trksid=m270

Yank

Doc Mark
08-12-2008, 09:36 AM
Greetings, Friends,

Many thanks for all the outstanding information and suggestions!! Much appreciated! Heather, I have drawn out the circuit your suggested, and as I'll be using the very same components as are you, I feel this should work out very well for me. Thanks a ton!!

I'll contact Mike Caldwell, if he's around, and see if I can get a replacement mounting bracket for my 2405. If all else fails, I'll go another route, which is OK, too.

Thanks, again, to one and all, for your suggestions! This is what makes LH such a fantastic resource! Take care, and God Bless!

Every Good Wish,
Doc

hjames
08-12-2008, 09:52 AM
Well, send your thanks to 4313B, its his schematic - I just pointed you at it. But thank him for sharing it with us!



Greetings, Friends,

Many thanks for all the outstanding information and suggestions!! Much appreciated! Heather, I have drawn out the circuit your suggested, and as I'll be using the very same components as are you, I feel this should work out very well for me. Thanks a ton!!

I'll contact Mike Caldwell, if he's around, and see if I can get a replacement mounting bracket for my 2405. If all else fails, I'll go another route, which is OK, too.

Thanks, again, to one and all, for your suggestions! This is what makes LH such a fantastic resource! Take care, and God Bless!

Every Good Wish,
Doc

Doc Mark
08-12-2008, 11:58 AM
Well, send your thanks to 4313B, its his schematic - I just pointed you at it. But thank him for sharing it with us!

Hello, Heather,

Absolutely!! Thanks, VERY much, 4313B!! Your efforts to educate us and to share your vast knowledge with us, is admirable, and very much appreciated!! :applaud::applaud: Take care, and God Bless!

Every Good Wish,
Doc

Doc Mark
08-13-2008, 09:31 PM
Good Evening, All,

I have been thinking about the circuit that I copied from Heather's link to 4313B's post, and it suddenly dawned on me that the 2405 crossover point was about 8500HZ, wasn't it? I was hoping to cross this driver over at 10KHZ, instead of lower. The crossover I've heard most was 7KHZ, and I didn't like it, at all. How does 8500HZ compare to 10KHZ in sound quality? Thanks, very much, and God Bless!

Every Good Wish,
Doc

Fangio
08-14-2008, 04:45 AM
http://www.audioheritage.org/vbulletin/showthread.php?p=60870#post60870

..there's a reason why 077/2405 sound best above 8.5kHz.


With the 4-way networks they are crossed over higher actually

9.5kHz w/ 3143, 10kHz w/ 3145, from 2420/2421/2425.

Doc Mark
08-14-2008, 08:16 AM
Hi, Fangio,

Thanks, very much, for that great link! Outstanding food for thought in that long thread!! I think I'll build both the 8.5KHZ version, and also a 10KHZ version, and see which one I like the best. Again, thanks for turning me on to that wonderful thread! Informative, and quite entertaining, too!! :applaud::D Take care, and God Bless!

Every Good Wish,
Doc

4313B
08-14-2008, 08:42 AM
Compare the 2405 circuit in the 3107, N333/LX300/3133 and 3143 schematics.....

3145 and 3155 as well, but keep in mind that those two circuits use tapped autotransformers as did the 3114.

grumpy
08-14-2008, 10:31 AM
unless I hosed the tap model (possible), voltage drives into 8 ohms (ala std test fixture)
might compare like this: blue (3145/55) vs red (3107) ... using comparable L-pad settings.

If I'm way off, let me know and I'll pull the post.

4313B
08-14-2008, 11:54 AM
It looks familiar to me.

The explanation given to me was that it was thought they could just substitute in regular 0.16 mH inductors in place of the 0.16 mH tapped autotransformers back in those days.

Draw your own conclusions from that statement...

Keep in mind that the venues for these monitors were EQ'd so "it all worked out in the end".

grumpy
08-14-2008, 01:01 PM
If the ~7KHz dip shown in (earlier referred to) 2405 CLIO plots corresponded
to the peaking of the filter (closer to 9KHz), I'd claim intentional synergy, but
perhaps the explanation is simpler, as you have suggested.