How to use JBL K-120

[Dr.db]

Hey folks,

I own a NOS pair of JBL K-120 Alnico 12inch Woofers....

Now I`m wondering how they work the best.
So far I`ve read they shall be driven without lowbass etc.. but can be driven fairly loud with highpass.
They will run together with 2441 Drivers and 15inch subwoofer....

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So what would be the best frequency-range for these woofers ?
Where should I put the highpass-filter !? 100hz @ 12db, 200hz @ 6db etc...

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What enclosure is best ? 30liter sealed!?

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What kind of voicecoil do they use ? Do they really handle 100watts continous ?


Thanks a lot and have nice christmasdays!!!

Olaf

[Dr.db]

Has really none of you a clue ?

[macaroonie]

As a first step why don't you have a look at what the driver will do without filtering.
Download WIN ISD from here : http://www.linearteam.dk/ , the parameters for the D K and E 120 are in the applicaqtion. That driver does not do much below 80 anyway so a main - sub turnover at 100 - 120 will be easy to do. Go much above that and you will start to ' hear ' the sub.

[Dr.db]

Hi,


there will be a JBL 2235h in each speaker, so there shouldn`t be a problem with "hearing" a subwoofer.
I may did not mention this right...

I do not believe WIN ISD is a proper simulation programm, I allready had some strange output from this Data which did not compare to reality at all!
Some Cerwin Vega 18inch`s where supposed to work in 1,5 cubic feet etc...

[macaroonie]

Hi,


there will be a JBL 2235h in each speaker, so there shouldn`t be a problem with "hearing" a subwoofer.
I may did not mention this right...

I do not believe WIN ISD is a proper simulation programm, I allready had some strange output from this Data which did not compare to reality at all!
Some Cerwin Vega 18inch`s where supposed to work in 1,5 cubic feet etc...

Ah ! Well in that case ramp it up to 250 -300 to take the excursion out of the 120 and go from there. Under those circumstances you can use a pretty small ' dog box ' for the 120 .

I hear you about WIN sometimes it seems a tad optimistic as far as how small enclosures can be. As I recall it suggests 19 litres for good alignment for a 2206. That has to be wonk

[JeffW]

As I recall it suggests 19 litres for good alignment for a 2206. That has to be wonk

I think it was 16!

[jcrobso]

Here is the product info for the K series.
For a mid range speaker a sealed box would be good, I have also included T-S info.
This speaker was usually used in open back guitar amps, that is where one mine is.
How low you can use depends on how big the box is.
Have fun lets us know how it turns out!