Ring Radiator Comparisons

[tomee]

Hi ivica,
I think that is not the truth,
2404H:Frequency Response ( ± 3 dB): 4 kHz to 19 kHz,Usable Frequency Range ( - 10 dB): 3 kHz to 21.5 kHz
2405H:Frequency Response ( + 3 dB): 7 kHz to 20 kHz,Frequency Range ( - 10 dB): 6.5 kHz to 21.5 kHz
2402H:Frequency Response (±3 dB): 3 kHz to 15 kHz,Frequency Range (–10 dB): 2.5 kHz to 15 kHz
2403:105 dB SPL 5khz-21.5kHz @ 1watt 1 meter, freq range 5kHz-21kHz
It seems only 2402 can not reach 20khz
regards
Martin

for marketing purposes (because the market is fixated on 20kHz as some 'magic' number to reach), it appears that the 2405 wins.

[martin_wu99]

Hi Martin,

May be MY understanding about the upper frequency response of the driver is not correct, but looking at
the curves 2405 vs 2403
http://www.audioheritage.org/vbullet...l=1#post360551

on MY OPINION 2405 has higher FR then 2403, for the others You haven given us.

regards
ivica

Hi Ivica

Back to the previous question,why dose Westlake only choose 2403 to being used in his most expensive high-end speakers SM-1 and HR-7,but not 2405?it is beyond my ken

regards
martin

[martin_wu99]

for marketing purposes (because the market is fixated on 20kHz as some 'magic' number to reach), it appears that the 2405 wins.

Maybe JBL engineers themseve did not realize how good 2403 is untill Westlake reveal it.

[ratitifb]

Maybe JBL engineers themseve did not realize how good 2403 is untill Westlake reveal it.

i doubt of that but certainly it's true for a specific enclosure design for a specific use like Westlake recommends in studio environment...

[ivica]

Hi Ivica

Back to the previous question,why dose Westlake only choose 2403 to being used in his most expensive high-end speakers SM-1 and HR-7,but not 2405?it is beyond my ken

regards
martin

Hi Martin,

I have no exact answers, but
1. 2403 (owing to the ellipse-look horn mouth) is more attractive to be seen then "edgy" 2405 (slot)
2. May be they prefer 2403 wider vertical dispersion (up to 16kHz) as we have seen from the measurements
3. May be they not pay their their attention on FR over 16kHz (as just a few listeners can be aware of)

regards
ivica

[ivica]

Maybe JBL engineers themseve did not realize how good 2403 is untill Westlake reveal it.

May be, but not to forget some names that have been there at that time in JBL ( Mr. G.T, Mr. Gary Margulius,.....).

Reagrds
ivica

[Mr. Widget]

Back to the previous question,why dose Westlake only choose 2403 to being used in his most expensive high-end speakers SM-1 and HR-7,but not 2405?it is beyond my ken

I would bet Westlake has used the 2403 primarily due to it's rarity. Who else in the world has used them since the '80s... also, I don't think even Westlake has them any more. A few years back Ken Pachkowsky was scouring the used/NOS market trying to find a pair for them.

I'm going to say it is marketing driven not engineering/performance driven.


Widget

[pos]

IMHO the 2403 is far more usable than the 2405 (lower crossover point, much more controlled off axis behavior, etc.)
The on axis response of the 2405 is indeed more linear and a bit more extended (but really, how cares about extension above 17kHz ??), but if you look at unit to unit matching all these consideration become moot anyway...
Point is: on axis response can be equalized, beamwidth cannot...

[Dr.db]

Most people recommend the 2405 over the 2402 due to its wider freq. range....

But is their a lot happening above 15khz in reality ?
And is the usual individual aged above 30 still capable of hearing these frequencies anyway!?

[toddalin]

Most people recommend the 2405 over the 2402 due to its wider freq. range....

But is their a lot happening above 15khz in reality ?
And is the usual individual aged above 30 still capable of hearing these frequencies anyway!?

No, I don't agree. Most people recommend the 2405 over the 2402 due to the much more linear response at ~9kHz (even if they don't know it). Most of us have no problem with ~9 kHz and the drop out in the 2402 is substantial compared to the 2405. The ear really picks up on this on ride cymbols, etc., but also in vocal intelligibility.

[andychris]

Hello

I can get a pair of 2402 alnico with silver diaphragms,,, could you tell me if those diaphragms seem JBL original ? Ans silver diaphragms, is it a fine diaphragm because I've never heard one ?

Thanx

[ivica]

Hello

I can get a pair of 2402 alnico with silver diaphragms,,, could you tell me if those diaphragms seem JBL original ? Ans silver diaphragms, is it a fine diaphragm because I've never heard one ?

Thanx

Hi andychris,

It seems (to me) to be JBL original.
I have very good experience with 2405 "sliver-like" diaphragms,
but I have no experience with 2402 "sliver-like" diaphragm.

reagrds
ivica

[gibber]

Hello

I can get a pair of 2402 alnico with silver diaphragms,,, could you tell me if those diaphragms seem JBL original ? Ans silver diaphragms, is it a fine diaphragm because I've never heard one ?

Thanx

Hi andychris,

your fram seems original, but the bullet part of the horn seems to have been taken from the ferrite rather than alnico version.

My ferrite-sourced bullets (on the right) show the same outside removal of material at the wide end (near fram) as the one in your picture. Despite removal of material, they measure 43.8mm across -- half a millimetre more than the old bullet taken down from a 1970's alnico 2402 at 43.3mm shown on the left :



(note the machined entry into the scew-hole on the '70 bullet)


Side note: i would never have noticed it without having read this GREAT thread: my 2402H bullets have the 2405-fram layout, i.e. plane area at the bottom side of bullet is 36.6 mm instead of the '70s bullet's underside plain area being 35.6 mm across -- a whopping whole millimetre !

Ralph

[gibber]

Most people recommend the 2405 over the 2402 due to its wider freq. range....

But is their a lot happening above 15khz in reality ?
And is the usual individual aged above 30 still capable of hearing these frequencies anyway!?

This weekend i will visit a friend to give quite a full brace of varieties a go: He was lucky enough to get hold of a pair of cat-eyes and on the ETF.14 auction he got himself a pair of "extended-horn" bullets made from brass. These things exude luxury, will see if they live up the the hype (and will check whether their bullet's underside is machined for 2405 or 2402 frams )

Ralph

[toddalin]

Most people recommend the 2405 over the 2402 due to its wider freq. range....

But is their a lot happening above 15khz in reality ?
And is the usual individual aged above 30 still capable of hearing these frequencies anyway!?

The difference in what is heard is not so much what is above 15K, but what is actually happening in the 8-9K region. The 2402 have a much deeper dip in this area than the 2405, and the ear readily hears this difference as a loss of detail.