Adding a 2404H tweeter to JBL 4430 + 2123H

[screw_squirrel]

Hi! Everyone.

The main part of the improvement to the 4430 (http://www.audioheritage.org/vbulletin/showthread.php?27956-4430-2123H-a-way-to-improvement.) is done and I am very happy with it.
Now I am planning to add a 2404H to complete the project.
My first idea was to buy a M552 for the first cut at 300Hz and use the M553 for the higher cuts but the highest cut with the M553 is at 5KHz and several people told me that it was not enough if I wanted to use the 2404H with my system and improve the result.
So I think I should have to built a passive network and find the good hight of cut.

My questions are:
-At what height should I cut if I want to keep the coherence of the 2344A + 2426H couple?
-What slope would be the best? 6, 12, 18, 24dB per octave.
-Should I put an attenuator to match the sensibility between the 2344A + 2426H and the 2404H?
-Or should I change my idea and go through a 4 ways digital network?

Thanks to anyone who can enlight my search.
Eric

[screw_squirrel]

Well it seems that my improvement does not interest many of you seen the little reading on this topic and the number of response equal to zero ...
That said, I continued my research and I think my project will look like this:

- The filter will be passive.
- I'll cut at 8KHz as the 4-way monitor type 4344 MkII
- The slope will be 18dB per octave.
- There will be an attenuator.

Well, let's go! :rockon2:

[louped garouv]

Well it seems that my improvement does not interest many of you seen the little reading on this topic and the number of response equal to zero ...
That said, I continued my research and I think my project will look like this:

- The filter will be passive.
- I'll cut at 8KHz as the 4-way monitor type 4344 MkII
- The slope will be 18dB per octave.
- There will be an attenuator.



I am likely in the minority here,
but find that I tend to like shallow slopes in crossovers...


just a little story from my experience...
and how i figured out that I like shallower slopes....
I had stumbled upon an old pioneer crossover...
it was model SF-850, there are several other models in the series
the most prestigous being the D-23 or possibly the D24 (never actually seen one)

anyway, the thing with those crossovers is that they had selectable crossover and slope options... it was pretty fun trying the different configurations out, and hearing the differences....

If you can find a device that allows this sort of flexibility,
it may shorten the length of your research and testing...

good luck!

[1audiohack]

I bet you will be happy with the result. The 2123, 2344-2426, 2404 is a combination I keep coming back to, and love.

There seems to be, to me an almost equal benefit of getting the 10kHz and higher energy out of the 2344 as there is having a more suitable driver like a 2404 or 2405 take on the duty of producing that last octave of frequency.

I ended up crossing at 10kHz. I have done it both active and passive, usually 12dB.

I don't remeber the specifics or the additional signal delay required for the 2404. I can certainly look that up tonight.

My latest variation is a 2020, 2344-2426, it will get 2404's this weekend though.

[badman]

I tend to, as well, but as all other things audio, it's all about matching. Horns tend to behave very poorly at their low end cutoff, making a steeper slope desirable. Additionally, center-center spacing is larger with horns/large drivers a la JBL which can mean a significant increase in lobing behavior with lower order XOs.


I am likely in the minority here,
but find that I tend to like shallow slopes in crossovers...


just a little story from my experience...
and how i figured out that I like shallower slopes....
I had stumbled upon an old pioneer crossover...
it was model SF-850, there are several other models in the series
the most prestigous being the D-23 or possibly the D24 (never actually seen one)

anyway, the thing with those crossovers is that they had selectable crossover and slope options... it was pretty fun trying the different configurations out, and hearing the differences....

If you can find a device that allows this sort of flexibility,
it may shorten the length of your research and testing...

good luck!

[screw_squirrel]

I am likely in the minority here,
but find that I tend to like shallow slopes in crossovers...


just a little story from my experience...
and how i figured out that I like shallower slopes....
I had stumbled upon an old pioneer crossover...
it was model SF-850, there are several other models in the series
the most prestigous being the D-23 or possibly the D24 (never actually seen one)

anyway, the thing with those crossovers is that they had selectable crossover and slope options... it was pretty fun trying the different configurations out, and hearing the differences....

If you can find a device that allows this sort of flexibility,
it may shorten the length of your research and testing...

good luck!

Hi louped garouv!
shallow slope... well why not. But if I do so I think I should cut at least at 12KHz and only in a high pass mode. Am I right?

[screw_squirrel]

I bet you will be happy with the result. The 2123, 2344-2426, 2404 is a combination I keep coming back to, and love.

There seems to be, to me an almost equal benefit of getting the 10kHz and higher energy out of the 2344 as there is having a more suitable driver like a 2404 or 2405 take on the duty of producing that last octave of frequency.

I ended up crossing at 10kHz. I have done it both active and passive, usually 12dB.

I don't remeber the specifics or the additional signal delay required for the 2404. I can certainly look that up tonight.

My latest variation is a 2020, 2344-2426, it will get 2404's this weekend though.

Hi 1audiohack!
10KHz seems not bad but in my case I have the L-pad for 4430 that reduces to 12KHz (-6dB ~ +2 dB) and this may be somewhat near the frequencies cutoff...

[screw_squirrel]

I 've just received the drivers last friday.

48187

48188

48189

48190

48191

If you see something wrong just tell me! :D

[macaroonie]

Here is the information required to modify M553 MF / HF crossover point to max of 10KHz.

http://www.audioheritage.org/vbulletin/showthread.php?14471-M553-need-help&highlight=m553

If you want to go higher if you half the value of the tuning caps again from 0.0018 to 0.0010 you will have a max of about 18 KHz.
I found tuning by ear entirely satisfactory and after a few weeks settled on a setting that has become permanent.

Have fun

[martin_wu99]

I 've just received the drivers last friday.

48187

48188

48189

48190

48191

If you see something wrong just tell me! :D
So beaytiful! look at my 2404H

[ratitifb]

So beaytiful! look at my 2404Hprobably not exactly the same baby ... 2404H-1 for the 4628B when screw_squirrel uses the 2404H ;)

hi screw_squirrel, one of the two dia seems to have been bent :o: with respect to the voice coil gluing area ?? Did you double check it compared to the other ?

[1audiohack]

I have bought many 2404's new over the years, a pair when they first came out and possibly one of the last ones made, the last one to come out of the tent sale after being obsoleted and I can tell you with absolute certainty that the -1 notation is not concrete. There are two diaphragm possibilities as well as two phase plug possibilities and I have seen all the possible combinations the drivers I have bought new. More often than not defying the common convention.

Unless you have real measurement equipment and are very familiar with these you pretty much have to remove the inner / outer horn assembly from the motor to know what you have for sure.

I have made a study of these and need to start a thread with physical, impedance and frequency response measurements. Soon.

[ratitifb]

I have bought many 2404's new over the years, a pair when they first came out and possibly one of the last ones made, the last one to come out of the tent sale after being obsoleted and I can tell you with absolute certainty that the -1 notation is not concrete. There are two diaphragm possibilities as well as two phase plug possibilities and I have seen all the possible combinations the drivers I have bought new. More often than not defying the common convention.

Unless you have real measurement equipment and are very familiar with these you pretty much have to remove the inner / outer horn assembly from the motor to know what you have for sure.

I have made a study of these and need to start a thread with physical, impedance and frequency response measurements. Soon.very interesting ;)

According to JBL the 2404H-1 uses the 2402 diaphragm for an extension to the lower frequency range and the 2404H uses the 2405 diaphragm. The UHF drivers from my 4628B are white stamped -1.

[1audiohack]

They very well may be what they should be. The last three I got were white stamp marked -1 and had D16R2405 diaphragms with the small phase plugs that measure 1.600 wide at the bottom, the "normal" most common plugs measure 1.720" like the bullets and slot plugs.

[martin_wu99]

I have bought many 2404's new over the years, a pair when they first came out and possibly one of the last ones made, the last one to come out of the tent sale after being obsoleted and I can tell you with absolute certainty that the -1 notation is not concrete. There are two diaphragm possibilities as well as two phase plug possibilities and I have seen all the possible combinations the drivers I have bought new. More often than not defying the common convention.

Unless you have real measurement equipment and are very familiar with these you pretty much have to remove the inner / outer horn assembly from the motor to know what you have for sure.

I have made a study of these and need to start a thread with physical, impedance and frequency response measurements. Soon.
Very good!expecting your thread about 2404 studying.

[screw_squirrel]

Here is the information required to modify M553 MF / HF crossover point to max of 10KHz.

http://www.audioheritage.org/vbulletin/showthread.php?14471-M553-need-help&highlight=m553

If you want to go higher if you half the value of the tuning caps again from 0.0018 to 0.0010 you will have a max of about 18 KHz.
I found tuning by ear entirely satisfactory and after a few weeks settled on a setting that has become permanent.

Have fun
Thank you for the link!
It's very interesting, unfortunatly i am not able to do the mofification by myself but it could be done by a spécialist.
The good fact is that i could buy a M552 to cut at 300Hz (between 2235H and 2123H) and then go into the M553 for the two other cuts at 1Khz (between 2123H and 2426H) and 10KHz or 12KHz (between 2426H and 2404H)...
Maybe the solution, who knows! :D

[screw_squirrel]

very interesting ;)

According to JBL the 2404H-1 uses the 2402 diaphragm for an extension to the lower frequency range and the 2404H uses the 2405 diaphragm. The UHF drivers from my 4628B are white stamped -1.
Hi ratitifb!
First of all,I had difficulties to open it because of the small gap between the bolt head and the stiffener rib of the horn. See (http://nsm04.casimages.com/img/2010/10/28/101028071138607127010573.jpg). The Allen key does not pass! I have to buy a short one.
Well the "7-16-92" one seems to be a little bit worn compare to the "7-21-92".
But I have not compare yet in terms of voltage or sound. I want to built a passive crossover in a simple way. Like this (http://4.bp.blogspot.com/_-i1wjkiEGro/TFrD8zzkuMI/AAAAAAAABcA/p4rm_3GOYyg/s1600/P1020197.JPG) or this (http://4.bp.blogspot.com/_-i1wjkiEGro/S1Bqz50qPZI/AAAAAAAABSs/yMr0tQcZb-U/s1600-h/P1010614.JPG). But it's not as cheap as I though...
Here's the diagram (http://nsm04.casimages.com/img/2010/11/05/101105083313607127061402.jpg) it's a high pass 6dB@12KHz...

[pocketchange]

Is it possible that the assembly was not secured from rotating when the fastener was torqued?

[screw_squirrel]

Is it possible that the assembly was not secured from rotating when the fastener was torqued?
Well, maybe, I don't know... :confused:

[screw_squirrel]

Hi All!
Does anyone know what is the exact impedance of 2404H at 12 KHz??
I can not read the value on the chart documentation.
It looks like 10 ohms.
Can anyone confirm?
I want to achieve a high pass filter at 12 kHz @ 18 dB.
Thank you in advance.

[pocketchange]

When replacing the 2404H VC, the Phase Plug (bullet shaped piece that is not supposed to be allowed to turn/move) should be secured from ANY rotation, so's not to allow anything but clamping pressure on the voice coil.

OR, you could destroy a perfectly good VC......

[Ruediger]

Hi All!
Does anyone know what is the exact impedance of 2404H at 12 KHz??
I can not read the value on the chart documentation.
It looks like 10 ohms.
Can anyone confirm?
I want to achieve a high pass filter at 12 kHz @ 18 dB.
Thank you in advance.

My suggestion: make the 2404 look like an 8-Ohm resistor by connecting a 40-Ohm resistor parallel to it, then get an 8-Ohm L-pad and connect the 8-Ohm 2404 || 40-Ohm to the L-pad, then calculate the Xover for 8 Ohms.

Ruediger

[1audiohack]

They are between 8.5-9.0 Ohm at 12k. I will double check after work

[pos]

lots of variation there, it seems:
http://www.audioheritage.org/vbulletin/showthread.php?6368-Ring-Radiator-Comparisons&p=62922&viewfull=1#post62922

[Robh3606]

Here's what I measured using WW2 on one of mine,

Rob:)

[screw_squirrel]

Thank you all! You're GREAT! :applaud::bouncy: