JBL 4346 DYI with 2123H

[lordoflight]

Dear All,

I am new in this forum and first off all I would like to thank you all for your passion in JBL vintage speakers. I believe they are outstanding. I am currently building a 4346 JBL with the following speakers:
LF 2235H (reconed on a E140 basket with a mass ring of 51 grams)
MF 2123H
HF 2425J with 2307 horn dyi
UHF 2405

Considering the above, I have the following pleas to you guys:
1. How can I integrate the 2123H speaker in this build? I want to use the CC crossover scheme provided by Mr. Giskard here http://www.audioheritage.org/vbullet...l=1#post319098
I will not bi-amp!
2. Does anyone have all the specs of the 2307 horn. I want to machine a pair. I mean every dimension... including the arches. Sadly I don't have an original so I can make a mold after the horn.

Thank you so much for your input.

[lordoflight]

Hi guys,

I'm back again although no reply to my post so far...

Nonetheless, can you tell me what would be the best choice for a crossover for my DYI project? I want the best of the best.
A charge Coupled version or a plain high end cap version?
An also could you indicate the best schematics for such recommended crossover?

Thank you very much in advance.

[bldozier]

Hi guys,

I'm back again although no reply to my post so far...

Nonetheless, can you tell me what would be the best choice for a crossover for my DYI project? I want the best of the best.
A charge Coupled version or a plain high end cap version?
An also could you indicate the best schematics for such recommended crossover?

Thank you very much in advance.

Any plans.

[.:hb:.]

1. How can I integrate the 2123H speaker in this build? I want to use the CC crossover scheme provided by Mr. Giskard here http://www.audioheritage.org/vbullet...l=1#post319098

That's not easy. 2122H and 2123H aren't that much alike. The former is much more a bass than the latter. 2123H is a lot louder and a true midrange.
To my knowledge, something like this has been done on a 4345. perhaps someone around here knows about that.

[martin2395]

I have 4343 with 2235H, then 2123H coupled to 2450J (2-inch) - charge coupled 3155 network works perfectly.
Consider bi-amping to lose the "wooly-ness" of the foam edged "15, highly recommended.

[Chas]

I have had good success using the 4344MkII crossover network (charge coupled) with a 2123 as a substitute/replacement for the 2122 and its associated network.

I highly recommend you bi-amp @290-340 HZ fourth order, the difference is significant.

Note the above is based own listening only, I have not performed any measurements.

[lordoflight]

Please see the graphs

pink noise full on lpads

1 all drivers together
2 mid only
3 hf only
4 uhf only
5 lf only

the dropoff is At arround 1200 hz.

Checked on l-pads connections they are OK.

[lordoflight]

I really appreciate you taking the time for little ol' me. I am trying to finalize this project and enjoy the music.

So, in order not to be any misunderstanding I am attaching the schematics og mr Giskard network frim which I have used the Hf and Uhf sections. The mids and lf are from the mkII.
Let me get back to you with the drop off issue. I want to replicate the test with all drivers full on.


In the meantime if you can Identify a voltage issue in the network i will be most grateful.


getting back to you also on the phasing issue. I know the Beyma is different than the 2405 And I wired it properly.

[Ian Mackenzie]

If you wish take a pic of the analyser for each test and up load for the overall response L pad full.

Then the phase reversal of the HF (only), then phase reversal of the Beyma only.

Then if you can the individual response of the mid, hf and uhf.

[Ian Mackenzie]

Okay


Can you check that the L pads are correctly connected?

On the L pad 3 is the input from the crossover, 2 goes to the driver , 1 is ground.

I have previewed the schematics and it needs be looked at in context that the Giskard schematic was prepared for the 2122 mid driver and the 2235 or 2245 woofer.

The mid driver is less sensitive than the 2123 mid driver.

I think the woofer used in the 4344mk11 is slightly more sensitive than the 2235 and is close to the 2245 woofer.

I will need to check the voltage drives but L pad on your mid driver may not have the same range of adjustment as the HF and UHF. This relates to your comment that up full is best.

[lordoflight]

Never thought my issues will attract so much help. Thank you guys you are really something...


i used RTA app from onyx. i have an Iphone 5s. i took the measurements as follows

the full drivers at about 90 cm in front of the speaker

each individual driver was measured on axis at about 30 cm.

if you give me indications i can repeat the measurements with your parameters.

[lordoflight]

Hi guys,

After much tinkering I decided to use the LF and HF sections of the 4344MKII network and the HF and UHF sections taken from Mr. Giskard 3155 but I decided to take out the battery. This means no CC crossover and no bi-amp. I used instead Mundorf Evo Oil capacitors bypassed with Vishay 0.01 microF and high quality mundorf coils and resistors. I will upload a picture of it soon.

[Ian Mackenzie]

Hi guys,

After much tinkering I decided to use the LF and HF sections of the 4344MKII network and the HF and UHF sections taken from Mr. Giskard 3155 but I decided to take out the battery. This means no CC crossover and no bi-amp. I used instead Mundorf Evo Oil capacitors bypassed with Vishay 0.01 microF and high quality mundorf coils and resistors. I will upload a picture of it soon.

I assume you meant LF and mid sections of The 4344k11 network.

Because you have used 2 different network this likely hood of the voltage drives being balanced is remote.

Why did you not use the complete 4344mk11 network?

I recommend buying the 2308 off eBay and installing then reassess before ou o anything.

The lense alters he response of the HF horn. It would honk off axis without the Lense.

[lordoflight]

here is the picture of the crossover

[lordoflight]

Behold my babies! The l-pads are big Visatons. The crossovers are encased in big amplifier boxes. You can check my previous post for the components in the crossover. I used Jentzen JAD cables 2.5 mm OFC. The binding posts were ordered from china. They say its copper but in fact is brass. The cables were soldered with Jentzen silver solder. the drivers are:

LF - JBL 2235 - Actually a 2235 cone on a E 140 chassis

MF - JBL 2123

HF - JBL 2425 J with 2307 horn

UHF - Beyma 21CP/F

Any thoughts?