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Butch Adams
03-30-2005, 07:29 PM
Can someone explain the major differences (besides the obvious phisical differences) between the 2402, 2404, and 2405?
Which one is the most desirable for a home system?

Robh3606
03-30-2005, 07:54 PM
Just check out the JBL Pro site for the particulars. 2402's go low but not as high say 15K also a very tight patern 40 degree Cone??, 2404's can go down to 3k and up to 20K with a wide CD Horn 90X90 the 2405 runs from about 8k up to 20K and has wide horizontal but narrow vertical patern especially at the top of it's range. For home either a 2404 or 2405 depending on the application.

http://www.jblpro.com/pages/components/uhf_drvs.htm#2402H

Rob:)

GordonW
03-31-2005, 12:31 PM
Um, IME, running a 2404 below 5000 Hz is a recipe for a blown diaprhagm.

If you look, while JBL "officially" calls the crossover in the 4612 Cabaret cabinet "3000 Hz"... if you do the math for the tweeter crossover components, it's an electrical crossover between 4500 and 5000 Hz. And we used to blow enough 2404s in those, to warrant putting a fast-blow fuse between the crossover and tweeter...

IMHO, the 2404 is best for a home app, followed by the 2405, and lastly, the 2402. It's a matter of dispersion... the 2404 has about a 100x100 degree dispersion, the 2405 about 40 degree vertical by 100 degree horizontal dispersion, and the 2402 has a 40x40 degree dispersion. The 2404 will definitely be the trick, in any situation where some of the audience will be significantly off-axis any of the time...

Regards,
Gordon.

JBL Dog
03-31-2005, 01:30 PM
If you look, while JBL "officially" calls the crossover in the 4612 Cabaret cabinet "3000 Hz"... if you do the math for the tweeter crossover components, it's an electrical crossover between 4500 and 5000 Hz. And we used to blow enough 2404s in those, to warrant putting a fast-blow fuse between the crossover and tweeter...
Regards,
Gordon.

Though I will still give the 2404 high marks (especially in the Cabaret series 4612), I have to agree with GordonW, 3000hz is way too low of a crossover point. Blown phragms are the main reason I quit using the 4612's in my DJ rigs. I ended up fusing them them with 1 amp fast blows .... which were effective, but blowing all the time!

:banghead:

Mr. Widget
03-31-2005, 01:59 PM
If you can work with a very high crossover point of 10KHz, I'd go with the 2405, but it's certainly a matter of personal preference.

If seeking these on the used market, all 2405s (077s) have the same impedance of around 10ohms despite what they say on the back. All 2402s (075s) are also the same... I haven't measured them. The 2404s use the 2405 diaphragm.

Widget

Robh3606
03-31-2005, 02:27 PM
"Um, IME, running a 2404 below 5000 Hz is a recipe for a blown diaprhagm."

"If you look, while JBL "officially" calls the crossover in the 4612 Cabaret cabinet "3000 Hz"... if you do the math for the tweeter crossover components, it's an electrical crossover between 4500 and 5000 Hz. And we used to blow enough 2404s in those, to warrant putting a fast-blow fuse between the crossover and tweeter...'


I hear you but read their specsheet for the 2404. 3k 12dB slopes????? that's what it says. At home with 10 watts I doubt you would blow one. In a live setting PA cabinet in a heartbeat. Never made sense to me either with the 2405 and 2404 using the same diaphram. That fuse is a good idea. Surprised they never dropped the bulbs in to protect them.

Rob:)

hiQ
07-12-2006, 09:24 AM
[If you look, while JBL "officially" calls the crossover in the 4612 Cabaret cabinet "3000 Hz"... if you do the math for the tweeter crossover components, it's an electrical crossover between 4500 and 5000 Hz. And we used to blow enough 2404s in those, to warrant putting a fast-blow fuse between the crossover and tweeter...]

If I can revive this thread:

I want to use a 4612B crossover (because I have a pair) with one (or two) 104H-2 (s) and a 2404H (not H-1 etc) with a 800 hz (or so) crossover from a 2202H on the low end in a guitar rig.

I have been experimenting with this configuration tri-amped (I only really need one 104H in the rig) and it is great, but the 2404 must come in at 5 khz for best performance (this is a relatively low level 7 string jazz guitarist here).

I would like to try a passive setup in order to use a tube (remember them) power amp (these babies are heavy and expensive so triamping is out).

I am now encouraged seeing GordonW's comment on the 4500-5000 Hz operation of the x over.

Perhaps there is another crossover that would be better suited (L220? except it has some time alignment).

I would greatly appreciate comments from the people here who are so obviously wizards.

Thanks in advance. :cool:

I must add a disclaimer. I have musical expertise (I hope) and practical experience but little technical lexicon fluency. :blink:

Zilch
07-12-2006, 09:51 AM
Try 3105 circuit. Parts are all of ~$30.

I've never used it with 104H, but it's easily tweakable:

http://www.jblproservice.com/pdf/Network%20Schematics/3105%20Network.pdf

Adjust the LF values (lowpass for your MF) for 8-Ohms, and cascade with your 800 Hz filter highpass.

Look also to SR three-ways, like 4628B, perhaps, for other approaches:

http://www.jblproservice.com/navigation/Network%20Schematics.html

Robh3606
07-12-2006, 10:41 AM
Passive your going to run into issues with the 104H midranges. The 2202's have good sensitivity around 100DB or 6% efficency. I don't see how you can run them passive without a drop out over the range covered by the 104's. I am not sure what the sensitivity is but I would quess in the lower to mid 90's or so. You may have to double them up as the 2202 set's the system sensitivity.

Rob:)

hiQ
07-12-2006, 01:01 PM
The 104-H sensitivity (800hz through 5 khz) goes from 91db up and bumps (barely) 95db (the 2105 ramps higher, I just don't have one).

Currently I am (mostly) driving at (around) -10db out of a limiter into a three way electronic (unity gain) 2nd order into 180 watts for the 2202 and 45 watts each for one 104H and one 2404H.

The 104H and 2404H I back off 4 db on the input of the power amp (I could easily do so on the crossover but the amp has marked values).

The curious thing of course is this is a magnetic pickup which is virtually all midrange and I am using a guitar preamp which is designed (of course) with this contour in mind. It is also an eq which will work with a single 'full range' speaker (although the tweaking would be different).

One of the great problems in the sound of the jazz guitar is to tame the midrange without loosing all of the high end. Typically you use a .05 mf cap at the instrument but it is not perfect.

Rock guitar types (I use the term very loosely) are looking for a much much brighter mid range. Or at least they tolerate it.

For a jazz tone this three way system is a dream come true. I don't know what will happen (exactly) with a passive system. Perhaps this gives a hint, I hope.

It is not the same beast as a pre recorded music system. In fact probably rather far from it.

To sum it up, I got two 104-Hs because looking at the numbers suggested, as you say, that it would be a balancing act and yet it doesn't seem so much a problem.

I will certainly know more when I try a passive setup.

I hope this is informative to the question. :)

hiQ
07-12-2006, 01:09 PM
Try 3105 circuit. Parts are all of ~$30.

Adjust the LF values (lowpass for your MF) for 8-Ohms…

I am so sorry to have invoked (but greatly appreciative of the expertise) a response beyond my meager understanding. :blink:

scott fitlin
07-12-2006, 01:17 PM
As everyone has already said, 3K is just too low a xover point. However, I do like the 2404, and I run six of them, 1 on each stack, no fuses, no nothing, just six tweeters on a Crown D-75, 3 per channel in parallel. Crossover point, 7K, 18db slopes, NEVER blew one yet!

And I run my system hard at times.

I actually prefer the 2404 to the 2405, a bit softer sounding to my ears.

mbd7
07-12-2006, 03:00 PM
Scott, I assume you're tri-amping these ?

scott fitlin
07-12-2006, 03:43 PM
Scott, I assume you're tri-amping these ?Yes, the 2404 is part of a tri amplified 3 way full range, and I have sub bass and super tweeter augmentation, a quasi 5 way if you will.

:)

mbd7
07-12-2006, 03:54 PM
Sounds very good... too bad I'm to far away to hear it!

Zilch
07-12-2006, 04:16 PM
I am so sorry to have invoked (but greatly appreciative of the expertise) a response beyond my meager understanding. :blink:Oops, sorry.

The 3105 crossover circuit I recommended is for a 16-Ohm midrange; the component values in that part of the circuit would have to be adjusted if you tried to use it with an 8-Ohm driver.

HOWEVER, it now seems you'll be needing to use TWO 104H-2s, in which case, wired in series, they will total 16 Ohms equivalent, and so it may be directly applicable.

You have to start somewhere. For $30, build one up, feed it everything above 800 Hz and see if it works for you. It's just four components plus an L-pad to balance the tweeter....

hiQ
07-13-2006, 03:26 AM
Wilco Zilch, I will try that. Thank you.

[Passive your going to run into issues with the 104H midranges. The 2202's have good sensitivity around 100DB or 6% efficency. I don't see how you can run them passive without a drop out over the range covered by the 104's.…]

Robh3606 is absolutely correct. I put together a passive patchwork (my 800 hz proved to be 1200 hz) and I have some work to do. The 2202 runs away in this setup.

[If you look, while JBL "officially" calls the crossover in the 4612 Cabaret cabinet "3000 Hz"... if you do the math for the tweeter crossover components, it's an electrical crossover between 4500 and 5000 Hz.…]

Using the 4612B net I have with two 104H-2 (s) the crossover point appears to be 5 khz
(am I affecting the crossover point with the impedance mismatch).

For sometime I used a 2404H with an E-110 crossed at 3500 hz with no ill effect but I never drove it very hard. Sonically the 2404H seems much better to me coming in a 5 khz. :o: