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View Full Version : Is this Kombination possible (X-Over) 075/2397/4520 ???



Richard Long
11-27-2008, 11:17 AM
hi,

is this 3-way kombi possible (active x-over)? i mean the crossover between 2397 and 4520 ! is it possible do drive the 2397 to 800 hz ?

Hofmannhp
11-27-2008, 11:39 AM
hi,

is this 3-way kombi possible (active x-over)? i mean the crossover between 2397 and 4520 ! is it possible do drive the 2397 to 800 hz ?

Hi Richard,

I guess the 2397 isn't the right horn for the 4520, but it may also work.
The 4520 does no good job in the region between 300Hz and 800Hz and the 2397 has it's lowest possible crossover frequency in the 800 Hz area.

But for me, the 2397 is one of the best sounding horns for hifi from the vintage series and mounted together with a 2441.....wow.

HP

Mr. Widget
11-27-2008, 11:39 AM
...is it possible do drive the 2397 to 800 hz ?You bet! Just step back when you turn them up.:)


I guess the 2397 isn't the right horn for the 4520, but it may also work.

The 4520 does no good job in the region between 300Hz and 800Hz...Life's a series of compromises.



Widget

Richard Long
11-27-2008, 11:59 AM
The 4520 does no good job in the region between 300Hz and 800Hz and the 2397 has it's lowest possible crossover frequency in the 800 Hz area.


I thought the "normal" hi-x-over is 800 hz for the 4520 :blink:

Mr. Widget
11-27-2008, 01:31 PM
I thought the "normal" hi-x-over is 800 hz for the 4520 :blink:HP has these speakers in his collection... if he says that the output is less than ideal between 300Hz and 800Hz, I'd be inclined to believe him.

I assume this due to the fact that the rear wave is horn loaded and that above a certain frequency 300Hz??, these speakers are direct radiators. I am guessing though as I have never played around with these speakers. That said, what you are suggesting will "work"... and it may just what you are looking for.

As for the 2441 and 2397... I find 1200Hz is a better crossover point in a studio monitor type application.


Widget

Hofmannhp
11-27-2008, 02:27 PM
....
I assume this due to the fact that the rear wave is horn loaded and that above a certain frequency 300Hz??, these speakers are direct radiators. ....

As for the 2441 and 2397... I find 1200Hz is a better crossover point in a studio monitor type application.
Widget

Hi,

as mostly...Widget is right.:)

I talked about this frequency area between 300 and 800 in cause of something like "combfilter" effects caused by the distance between the woofer cone and the hornmouth of the 4520. But I always wonder why this is so the case in the area under the 800Hz??
This effect is less with the 4530 double scoop.

HP

subwoof
11-27-2008, 05:21 PM
JBL published a note sheet that outlined used for that exact combination using a 3110 crossover ( 800hz ) for cinema, theater and other playback systems. I posted it here some time ago and if I find it I will do so again. The 2397 and 2390 were interchangeable in that catalog.

Yeah the cone is a direct radiator above 150 but you SIT directly in front of it! So what if the response isn't flat - with that 60hz +6db punch you will never go back to a vented foam surround box unless you need output below 30. Remember that the lowest note on the largest piano is 32.

My first JBL setup was a 4530 / 2205 / 2390 / 2441 / 3110 and it positively kicked ASS. Fresh out of 2 yr college and working for a SR installer that had a back room full of odds and ends. Borrowed this and traded for that, it was the beginning of the end for me. 30 years later I am STILL at it.

In fact I will be building 4 of them this spring and making the C34 cabinet variant ( cutaway rear edges for corner placement ) for a friend.

BTW the 4520 is the double..:)

sub

pos
11-28-2008, 12:35 AM
Using a 4435-style alignement could be a solution to avoid comb filtering:
One of the two 15" is 1st order low passed at ~150Hz, and the other one runs to 800Hz, with the horn on its top.
I guess some EQ will be needed to raise the low mids...