JBL 4365 Active Crossover settings

[jarrods]

then I can duct tape them to my head by the ears and do the perfect listening position measurement!

Not as funny as it may seem. When I worked at Deakin University building up electronic/computing rigs for research academics one Senior Lecturer in Psychology was doing basically that. Dr Simon Oldfield was using a dummy head (not some cheap model used to display hats etc but physical mimic of real human head) and he had put tiny condenser microphone elements inside where the eardrums would be. He would record things in anechoic chamber and play back with a rig that just had two simple speakers above your head. One day he recorded jingling his keys around the dummy head and then played it back to me while I was sitting in the subject chair. You could hear the keys go around your head, even fully behind you. I have never heard such accurate pinpointed 3D sound as good as this in my life and this was some 30 years ago. He went on to do research for Australian Dept of Defence on advanced auditory cockpit displays for fighter planes.

[ivica]

Not as funny as it may seem. When I worked at Deakin University building up electronic/computing rigs for research academics one Senior Lecturer in Psychology was doing basically that. Dr Simon Oldfield was using a dummy head (not some cheap model used to display hats etc but physical mimic of real human head) and he had put tiny condenser microphone elements inside where the eardrums would be. He would record things in anechoic chamber and play back with a rig that just had two simple speakers above your head. One day he recorded jingling his keys around the dummy head and then played it back to me while I was sitting in the subject chair. You could hear the keys go around your head, even fully behind you. I have never heard such accurate pinpointed 3D sound as good as this in my life and this was some 30 years ago. He went on to do research for Australian Dept of Defense on advanced auditory cockpit displays for fighter planes.

Hi jarrods,

Such experience can be expected, but the problem in real sitations, is more complicated, as a listener, while listening live music, rotates his head (left-right, up-down,...), depending to his interest or towards the part of the orchestra he is mostly interested in, and I believe that is the main reason that usual recordings are not made using "using a dummy head", but may be there are much more other reasons (I believe)

reagrds
ivica

[macaroonie]

https://youtu.be/QQzS3yReIx0

[bubbleboy76]

Now I have received calibrated mic.
I will do new mesurements as soon as I get the house free from kids
I also did a new soundcard calibration today, including the dbx 260. See the attached picture.
The yellow line is including the dbx (on full passtrough), the other line show only the Focusrite 2i2 soundcard.

[ivica]

Now I have received calibrated mic.
I will do new mesurements as soon as I get the house free from kids
I also did a new soundcard calibration today, including the dbx 260. See the attached picture.
The yellow line is including the dbx (on full passtrough), the other line show only the Focusrite 2i2 soundcard.

Hi,
so almost no error.

regrads
ivica

[bubbleboy76]

Hi,
so almost no error.

regrads
ivica

Yes, that was anticipated, but it is still nice to know.

I will include the dbx in the timing reference channel for the next measurements, previously I only had the soundcard loop-backed.

[bubbleboy76]

Looking in the mic calibration report...
As worst-case examples, the mic was 15Db wrong a 5Hz, and 3Db wrong at 12500Hz.
That is pretty significant.

[bubbleboy76]

Here is also phase showed in the calibrations of the soundcard, and the soundcard+dbx260.

dbx260 clearly affects phase a bit.

[Mctwins]

Hallo!

Here is my soundcard calibration with Tascam US-122MKII

With REW of course.....

Dbx260 is not a soundcard. Why do you calibrate with the dbx260?

[Mctwins]

Here is also phase showed in the calibrations of the soundcard, and the soundcard+dbx260.

dbx260 clearly affects phase a bit.

You must be doing something wrong here, or your soundcard is corrupt.

[bubbleboy76]

Dbx260 is not a soundcard. Why do you calibrate with the dbx260?

This is a very interesting question to me, but kind of philosophical with the small changes the calibration applies!

POS advised me to not use the sound card calibration at all, due to the insignificant errors.

For me, one reason for having the dbx in the calibration would be to take that device out of the equation, and get more generic dsp settings in the end. The dbx260 is not my end state, it has to few PEQs per separate channel/driver.

[bubbleboy76]

You must be doing something wrong here, or your soundcard is corrupt.

Why do you say this? My calibration of only the soundcard looks very much like your calibration. But it is hard to see the details with the dB scale you show.

It is kind of expected for a non dc-coupled device to introduce some phase shifts and high-pass filtering by the protective caps, don´t you agree? Just like yours and mine soundcard does as well shown in the diagrams (I am just assuming dbx260 is not dc-coupled, I do not know that for sure).

One way to find out would be if you try to do a calibration including your dear dbx260 in the loop

[bubbleboy76]

The settings I have now sounds absoluteley amazing. The best sound system I have heard

I do not want to post the settings here because it is POS work. It is up to him to post them here, when he finds it fit.

I can say, the current settings are no way near the ones I myself tried in the beginning of this thread.

I am still waiting to get a chance to do new measurements with my calibated mic.

I will also measure the stock passive filter again to compare.

I know now that there is nothing wrong with the stock 4365 passive filter. It is me prefering +9dB in the low frequencies. I have been ruined by having subs "too high for too long"

[Jonas_h]

So the upgrade you are experiencing is more bass when going from passive to active? To me it sounds like you could have settled with just adding some boost down low and use the speaker with the passive filter.

[bubbleboy76]

So the upgrade you are experiencing is more bass when going from passive to active? To me it sounds like you could have settled with just adding some boost down low and use the speaker with the passive filter.

Yes, I think so too. It would have solved my "problem".

But now, when I have heard the clarity and micro-dynamics of active crossover, and the difference time-alignement did, there is absolutely no way back.