2404 vs. 2405

[Alex Lancaster]

Hi:

I´d like to have opinions of 2404 vs 2405 for Hi-Fi use.

Thanks.

[scott fitlin]

the slot is a better sounding unit. I have 2404 baby cheeks and I always thought they were ok. But the slot is better still. More intricate sound quality.

Bi radial uses a plastic horn that some feel is what doesnt sound quite as good!

[GordonW]

I dunno... personally, I gravitate toward the 2404H, it just seems to have more "speed" on transients such as plucked guitar strings. May have something to do with the greater mouth area... the 2404 can go a bit lower (5000 vs 7000 Hz), before rolling off, than the 2405... I'm guessing it can simply move a bit more air...

Though, really, how can you go wrong with either, if you use them right?

Regards,
Gordon.

[Mr. Widget]

I was hesitant to post on this thread as I have never built a system with the 2404. I have heard them in existing systems, but you can't really explore a driver if you haven't really played with it a bit.

I have used plenty of 2405s however. The 2405 while rated down to 7KHz sounds pretty rough when used that low. I think the 2405 has better top end extension than the 2404 and is an excellent tweeter as long as it is used above 10KHz with an 18dB/octave slope. The 2404 is probably the tweeter of choice if you need a lower crossover point.

[scott fitlin]

Yes, the 2404 is good IF you have to cross over at a lower frequency, say in the 4 to 7K range!

Ive heard slots crossed over at 8K/18db per octave and I think they sound teriffic used this way!

What I meant when I described the 2405 as having a more intricate sound is top end extension. The shimmer on the top end with the 2405 is superior to the 2404.

But, 2405,s will sound rough if you cross them over at 7K.

I know good results can be obtained with either unit, and the choice really belongs to the end user and what they feel sounds best.

Ive been using 2404,s on my full range for years, and they work, but I tried a slot, crossed over at 8K and I like it better!

[slxrti]

I have both, and perfer the baby cheeks. the 2405 are brighter at the cost of being harsh.

slxrti

[Guido]

If you have the possibility to x-over at 8 kHz than use the 2405.
The top end is higher.

2405 vs 2405H I would prefer the 2405. Can't explain why. I think the response is even better and they sound more smooth. But that's not objective.

[Charley Rummel]

Hi, everyone:

For HIFI I favor the 2405 with proper EQing. I favor the 2404 in sound reinforcement applications.

That's my opinion.

Regards,
Charley

[boputnam]

"For HIFI I favor the 2405 with proper EQing. I favor the 2404 in sound reinforcement applications."

Me too. Dispersion characteristics and frequency response make the choice a "no brainer" (best for me... ).

[Ian Mackenzie]

The 2405 really sings with the correct Xover such as that used in the 4345, but it spits if run with a softer slope.

amcka

[Dave G]

I wondered as the 2404 is a small bi radial CD horn according JBL, then are you adding a eq boost or does it measure smooth out of the box so to speak.

I'm using 18 db 7k on these. I think there is the obvious tshh but perhaps not as much shimmer as I would like.

[John Y.]

Mr. Widget,

I remember that you recently made a comment regarding the 3107 crossover and how it was designed for use with the 2440 roll off, but I can't find it. Also, I can't find anything on the JBL search, except for it being in the tent sale.

In what system was the 3107 used?

Is it a three way? If so, with what midrange/woofer can it be used? 2206H? 2123H?

Thanks, John

[John]

Hi John Y The 3107 was used in the 4350 system. It is a 4 way but you bi-amp the twin 15,s and run the rest of the system from the 3 way 3107 crossover. I am sure you could use the 2440-2441-2445 drivers and get excellent results with any one of them.

[Mr. Widget]

Originally posted by John
I am sure you could use the 2440-2441-2445 drivers and get excellent results with any one of them.

Actually that is not the case. There is no filtering of high frequency roll off in the mid/HF output that is sent to the 2440 in the 3107. JBL designed the crossover with the inherent roll off characteristics of the 2440 in mind. The 2440 naturally rolls off above 8KHz and is 12dB down just above 10KHz. If you substitute a 2441 which is 12dB down around 18KHz there will be a noticeable overlap between the 2441 and the 2405. In the case of the 2445 which has even greater high frequency output there will be even more overlap.

JBL even calls attention to this very issue. I read in the "Goes into" or some other JBL literature that if you change the diaphragm in the 4350 from the 2440 to the 2441 you must modify the crossover.

If you compare the crossover for the 4350, the 3107, and the crossover for the 4355, the 3155, you will see what I am talking about. Admittedly the 3155 is a more sophisticated crossover in other areas as well, but the filtering that is provided for the 2441 blends well with the 2405. The steep 10KHz crossover for the 2405 also agrees with the earlier comments made by myself and others on this thread regarding how to get the best performance from the 2405.

http://www.jblproservice.com/pdf/Net...%20Network.pdf

http://www.jblproservice.com/pdf/Net...%20Network.pdf

[John]

If this is true about the lack of filtering in the 3107 network concerning the large format compression driver in the 4350 system then this would indeed be an issue and one would have to proceed with caution when using anything but the 2440 driver. Thanks Mr. Widget for bringing this to our attention.