Excess group delay and mismatched phase response

[RenPa]

View attachment 407172

These are the best measuring picks of pairs in your mdat. That step response growing back after 60ms is very odd, points to a non-zero DC offset in the impulse response.

Maybe Dirac hears you. Here a DLBC filter calculated with firmware update 3.12.00. (Although again this update doesn't fix any of the important bugs with Harman/Arcam/JBl receivers )

 

[ppataki]

Maybe Dirac hears you. Here a DLBC filter calculated with firmware update 3.12.00. (Although again this update doesn't fix any of the important bugs with Harman/Arcam/JBl receivers )
View attachment 420067

Not sure what we need to see here - is it that the step response graphs are more or less aligned post 25ms?

To be honest that huge oscillation would worry me; I have always been under the impression that the less oscillation the better but please correct me if I am wrong

This is how my current step response looks like with two subs (manually integrated) and Dirac Live (which hence 'sees' the subs already integrated)

And this is the Wavelet

 

[RenPa]

Not sure what we need to see here - is it that the step response graphs are more or less aligned post 25ms?

It was a follow up of @OCA post https://www.audiosciencereview.com/...-mismatched-phase-response.50523/post-2140825
only to tell that 3.12 seems tohave fixed what he saw.
Your wavelet are TOTALLY impossible to get with DLBC .
Here my last DLBC 3.4.4 filter front left+ subs DLBC on:

And the wavelet

we aren't in the same world.
Seeing the @OCA 's blast is doing with Neuron and Audy and his «à la Dirac filters» I don't know what fondamental principles he applies that Dirac doesn't to get his supposed huge extraordinary fantastic super results...a mystery...

 

[pollock0424]

I have given up on Dirac correction for a 2 ch system. Instead I'm just resorting to PEQ correction on my RME ADI-2 Pro FS. I have a separate 2 ch system. I still use Dirac on Integra DRX-8.4 for HT...


I'm tired of it and I don't have time to mess around.

 

[RenPa]

My system is for HT and stereo music. I am asking myself if it would be better to put my old miniDSP 2X4Hd in the chain, learn MSO, EQ my 2 subs for 2 seat positions and present only one sub to DLBC. Would DLBC messes less with GD in this configuration?

 

[ppataki]

My system is for HT and stereo music. I am asking myself if it would be better to put my old miniDSP 2X4Hd in the chain, learn MSO, EQ my 2 subs for 2 seat positions and present only one sub to DLBC. Would DLBC messes less with GD in this configuration?

You might not even need MSO, just do a level match for your fronts and two subs (e.g. use REW's SPL Align tool) measure the sub distances, enter the corresponding delay values into your DSP (whatever DSP you have) then set up a crossover (make sure it is Linkwitz-Riley, 24dB/octave, if possible linear phase, around 80Hz or whatever works for you based on your measurements) and then run Dirac Live (non-DLBC) to optimize your system which it will 'see' without the subs since you have integrated them already.

This is what I do as well and it works really really nicely

 

[RenPa]

I have an other question. I see that for only one of my speaker the surround left Dirac put a dotted line on the wrong peak in the measured impulse response as if it was choosing the wrong polarity which is not the case of course .
See the left picture is REW measured impulse of the surround left and the right side of the picture show how it was measured by Dirac Infortunatly I can't change the color code for that speaker in Dirac the doted line is at 0,72 mark

All my speakers are at the same polarity in REW, the first great spike up.
With DLBC filter on the corrected impulse response for the left surround is positive too as all others too. Is the starting «mistake» before calculate a DLBC filter important or not?

 

[OCA]

I have an other question. I see that for only one of my speaker the surround left Dirac put a dotted line on the wrong peak in the measured impulse response as if it was choosing the wrong polarity which is not the case of course .
See the left picture is REW measured impulse of the surround left and the right side of the picture show how it was measured by Dirac Infortunatly I can't change the color code for that speaker in Dirac the doted line is at 0,72 mark

View attachment 424268
All my speakers are at the same polarity in REW, the first great spike up.
With DLBC filter on the corrected impulse response for the left surround is positive too as all others too. Is the starting «mistake» before calculate a DLBC filter important or not?
View attachment 424265

It can be tough to get speaker polarity right, took me a lot of time to develop a working function for that in Neuron and it can still give false positives with external amps and dolby enabled speakers. I don't know how Dirac handles it but a dirty solution could be swapping cables of this speaker during measurements and then swap them back after Dirac calibration. Otherwise bass will be extinct from your SL/SR combo and distance of SL will be somewhat off.

 

[ppataki]

Is the starting «mistake» before calculate a DLBC filter important or not?

Yes, I believe it is a mistake, indeed
The dotted line shall be on the first peak
You can try what @OCA recommended above

Actually this is funny: last night I was also playing around with the polarity of my two subs in the living room and I managed to actually get rid of a ringing that I could not remove in the last 6 years......

 

[RenPa]

a dirty solution could be swapping cables of this speaker during measurements

Yes indeed. I measured the timing difference between the up and down peak; 13 milimeters. DLBC doesn't change satellites polarity, only the subs. Does it matter?

 

[OCA]

Yes indeed. I measured the timing difference between the up and down peak; 13 milimeters. DLBC doesn't change satellites polarity, only the subs. Does it matter?
View attachment 424401

No, that's fine. It will get the distance and also the EQ filters when crossing over that speaker with sub right. Just don't forget to run that calibration with speaker's polarity physically swapped back to normal.

 

[RenPa]

No, that's fine. It will get the distance and also the EQ filters when crossing over that speaker with sub right. Just don't forget to run that calibration with speaker's polarity physically swapped back to normal.

( I don't know how you manage your time in only 24 hours/day... The Entity... I said) Anyway, I wasn't clear. Is the difference caused by the mistake made by Dirac matters? In other words: is it enough to try the dirty solution you suggested? I am willing to try but to my amateur eyes 13 milimeters is not so important isn't?

 

[RenPa]

DL 3.12.1 surrounds positive polarity impulses Blue is the LEFT surround polarity positive when measured doted line on down peak

DL 3.12.1 surrounds mixed polarity impulses Blue is the LEFT surround polarity negative when measured doted lines are reversed now it is the RIGHT yellow doted line on the down peak
LEFT surround is BLUE

Dl 3.4.4 left surround polarity positive and right surround polarity positive
2 Doted lines are on down peaks for the 2 speakers impulses

DL 3.4.4 with left speakers polarity NEGATIVE right speaker polarity positive. Left surround is BLUE. 2 doted lines on the downward peaks

IN ALL CASES DL or DLBC 3.12.1 or 3.4.4 CORRECTED polarities are ALL POSITIVES

 

[RenPa]

I must say that since Arcam updated their firmware for v1.62_2057 I get a little bit better results with Dirac DLBC v3.4.4 filters.

 

[RenPa]

It can be tough to get speaker polarity right

The new DLBC update 3.13.2 seems having corrected the problem and seem to get speaker polarity better

I have a question about spectrogram and GD etc. while we are waiting to see if Dirac will change their philosophy about it in DLBC @ppataki . Some DLBC filters give large differences in spectrogram of each channels and some give a more even pattern from one channel to an other. For ex imagine one filter give 5 different timing for FR 40Hz on the x axis for each channel : 50m to 100m. Suppose that an other filter gives a more coherent timing for the same FR say between 62m and 75m. Is one better than the other spectrogram only in't enough to decide?

 

[ppataki]

Some DLBC filters give large differences in spectrogram of each channels and some give a more even pattern from one channel to an other. For ex imagine one filter give 5 different timing for FR 40Hz on the x axis for each channel : 50m to 100m. Suppose that an other filter gives a more coherent timing for the same FR say between 62m and 75m. Is one better than the other spectrogram only in't enough to decide?

I would go for the one with more consistent delay values across the channels
That should provide a more coherent experience