JBL 4365 Active Crossover settings

[bubbleboy76]

There is an post in the "system information" part of this forum for 4365, but no file is attached. Must been forgotten by that Giskard-guy

http://www.audioheritage.org/vbullet...php?29286-4365

[pos]

Who will convert the 4365 HF voltage drive into dsp-settings for me?!

If you manage to get your hands on high resolution voltage drive curves (or better still a txt files with frequency and amplitude columns) I can try to emulate them with rephase using settings that would be doable on your DSP crossover.
That being said, the passive network also tries to address the geometrical misalignment of the drivers withint the slopes, whereas it would typically be best addressed using delays and symmetrical slopes with a DSP crossover. This is exactly what GT did with the S3900 and S4700 "DSPification". But for that you need a good set of measurements.

[bubbleboy76]

If you manage to get your hands on high resolution voltage drive curves (or better still a txt files with frequency and amplitude columns) I can try to emulate them with rephase using settings that would be doable on your DSP crossover.
That being said, the passive network also tries to address the geometrical misalignment of the drivers withint the slopes, whereas it would typically be best addressed using delays and symmetrical slopes with a DSP crossover. This is exactly what GT did with the S3900 and S4700 "DSPification". But for that you need a good set of measurements.

Maybe plan a vacation to Sweden this summer POS?! I have a boat and live by the sea, I recommend it!

[4313B]

There is an post in the "system information" part of this forum for 4365, but no file is attached. Must been forgotten by that Giskard-guy

No, it was a thread wherein I posted the voltage drives of the K2-S9900, 4365, DD65000, DD66000, and DD67000 showing the similarities and differences. Anyway, I'll reload LEAP at some point and look at the files again.

[bubbleboy76]

But for that you need a good set of measurements.

Can you define this a bit more, please.
Should I measure each driver very close, like 5cm, or should I measure in the middle between them 1m away? Or some other way?

[pos]

Maybe plan a vacation to Sweden this summer POS?! I have a boat and live by the sea, I recommend it!

Hej, why not, and you could help me remove that pesky R141 on my nc400 modules
Seriously though, traveling is not easy with a 2 years old at home...

Can you define this a bit more, please.
Should I measure each driver very close, like 5cm, or should I measure in the middle between them 1m away? Or some other way?

You can follow GT's method as exposed in the S3900/S4700 DSP thread.

You should either not use any filter (outside of the protection caps of course, that will stay inline and can be considered part of the system) and filter/restrict your measurement signal. If you include a filter you should note it so that is can be taken into account (compensated) during the correction.
You will need a low noise floor in order to get an accurate view of the stop band.

You should take several measurements for each driver, at different distances and angles. No need to match levels or try to calculate delays between drivers at this point.
Then just send me these impulse with comment for each measurement (filters, distance, etc.).

[bubbleboy76]

I know what you mean, I have two little sons, a 3-year and a 10-month.
Please send me your email in a PM.
Can I send REW measurement files?

[Mctwins]

Hallo!

Here is something for you to read. I am using ARTA program and to me it is a better tool than REW.

http://www.artalabs.hr/papers/Mateljan-ELA-02.pdf

http://www.artalabs.hr/papers/Matelj...omResponse.pdf

http://www.artalabs.hr/AppNotes/AP4_...d-Rev03eng.pdf

on the other hand, I really don't understand what you are trying to achive with your speakers.

To me, the 4365 performs in a outstanding way and I trust what the designer has come up with in terms of aligning the x-over settings, voltage vs freq, constant directivity, power response and so on.....my room response shows this very well.

Good Luck and Happy Reading

[bubbleboy76]

on the other hand, I really don't understand what you are trying to achive with your speakers.

To me, the 4365 performs in a outstanding way and I trust what the designer has come up with in terms of aligning the x-over settings, voltage vs freq, constant directivity, power response and so on.....my room response shows this very well.

You have said this now a 1000 times. What I try to achieve is very clearly stated in this thread (if you take the time to read it), so the question is really what you are trying to achieve?
I know what you think about my little experiment, do not worry about that!

[bubbleboy76]

Hallo!

Here is something for you to read. I am using ARTA program and to me it is a better tool than REW.

http://www.artalabs.hr/papers/Mateljan-ELA-02.pdf

http://www.artalabs.hr/papers/Matelj...omResponse.pdf

http://www.artalabs.hr/AppNotes/AP4_...d-Rev03eng.pdf

Thanks for the links.
What is ARTA doing better? Worth the extra 79 euros?

[ivica]

It sounds insaneley good now
If I only could replicate this sound fully active, with that extra percentage clarity and dynamics, then I would be in heaven.
Who will convert the 4365 HF voltage drive into dsp-settings for me?! I promise to send some Swedish delicacies to you! (we have some scary stuff as well, fermented herrings, snus, cray fish etc)

Hi bubbleboy76,

It is very nice to have such interesting toys as JBL 4365 supported by DSP and several amplifier around. As You have said using active network and separated amp for driving bass driver would produce more realistic bass response as there would be no driver to network mutual interaction, especially in the about 100Hz ~ 200Hz region. I have done some calculation and it can be seen the driver to network interference. As 4313B has told such behavior has been discussed by G.T. while talking about 4345 speakers and his suggestion to drive its bass (2245) active.
From the figure it can be seen, too, why, when active driven, a kind of shelving from about 130Hz has to be done in order to emulate passive network driver driven.

The problem how to active drive Horn-driver combo is much more complex if You want to eliminate passive network. It would not be enough to emulate voltage network response only, as there are driver&horn and passive network mutual interaction. As You can see from the Italian 4365 presentation, off-axis response of the driver&horn combo has shown a kind of rise in the response from 3kHz to 9kHz relative ot on-axis measurements, so I would suggest You to use off-axis response about 15~20 degs off-axis, as a response You would equalize, I believe that after that less "aggressive" sound would be get.

While equalize the response, I would suggest You ONLY to use filters that would REDUCE part of spectrum, that means NEVER ENHANCE a part do spectrum, and try to use AS LESS as possible number of EQ filters.

From the mentioned 4365 presentation it can be seen that VHF (476Mg) driver and 045 are not time aligned. It seems to me that about 0.75ms ( about 25cm) delay has to be included int to 045 driver drive (if separated driven amp for UHF would be used). Bass to VHF driver (476) time alignment You have done jet.

regards
Ivica

[bubbleboy76]

Hi bubbleboy76,

It is very nice to have such interesting toys as JBL 4365 supported by DSP and several amplifier around. As You have said using active network and separated amp for driving bass driver would produce more realistic bass response as there would be no driver to network mutual interaction, especially in the about 100Hz ~ 200Hz region. I have done some calculation and it can be seen the driver to network interference. As 4313B has told such behavior has been discussed by G.T. while talking about 4345 speakers and his suggestion to drive its bass (2245) active.
From the figure it can be seen, too, why, when active driven, a kind of shelving from about 130Hz has to be done in order to emulate passive network driver driven.

The problem how to active drive Horn-driver combo is much more complex if You want to eliminate passive network. It would not be enough to emulate voltage network response only, as there are driver&horn and passive network mutual interaction. As You can see from the Italian 4365 presentation, off-axis response of the driver&horn combo has shown a kind of rise in the response from 3kHz to 9kHz relative ot on-axis measurements, so I would suggest You to use off-axis response about 15~20 degs off-axis, as a response You would equalize, I believe that after that less "aggressive" sound would be get.

While equalize the response, I would suggest You ONLY to use filters that would REDUCE part of spectrum, that means NEVER ENHANCE a part do spectrum, and try to use AS LESS as possible number of EQ filters.

From the mentioned 4365 presentation it can be seen that VHF (476Mg) driver and 045 are not time aligned. It seems to me that about 0.75ms ( about 25cm) delay has to be included int to 045 driver drive (if separated driven amp for UHF would be used). Bass to VHF driver (476) time alignment You have done jet.

regards
Ivica

Thank you very much for this helpful information!

My time-alignement delay of the woofer is not done the properly way yet, I only used my ears so far. Can you roughly calculate what is should be?

[ivica]

Thank you very much for this helpful information!

My time-alignment delay of the woofer is not done the properly way yet, I only used my ears so far. Can you roughly calculate what is should be?

Hi bubbleboy76,

It would be difficult to say what is time delay of the bass driver, in the box as it varies from about 15ms at 32Hz, to about 0.4ms ate 470Hz (with passive network applied), but using active network, delay would be preset too. Mentioned VHF driver&horn has about 25cm mechanical offset (I guess) , but applied VHF network ( passive or active) would introduce its time delay around crossover too, so time delay compensation can be get , may be experimentally, applying "square wave" signal, and then looking at the (in time domain) reproduced waveform. Changing time delay try to get the best reproduced signal.
A software like TRUERTA ( https://www.trueaudio.com/rta_abt1.htm ) can be very usefull as it can produce square wave signal, and can show mic received signal.

http://www.musicanddesign.com/Speake..._Analysis.html
http://sound.westhost.com/ptd.htm
http://www.bksv.com/doc/17-198.pdf

http://www.kirchner-elektronik.de/~k...AutoDSPeng.pdf

Have a Good Luck,

regards
ivica

[bubbleboy76]

thanks again ivica.
Yes, the physical distance is about 25cm.
I received the protection caps today. I am shocked by the size of them, I thought it should be a little small component

[ivica]

thanks again ivica.
Yes, the physical distance is about 25cm.
I received the protection caps today. I am shocked by the size of them, I thought it should be a little small component

Hi
As known: "there is no better enhancement .... then displacement (volume)"

regards
ivica