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Discussion Starter #3,121 (Edited)
No.
L&R and subs. It Are the same postion and 1 minute after.
Yes, I can try later to do that.
Sorry still don't understand exactly what your setup looks like and how you've performed measurements in REW.

Do you have 2 subs and you've selected "Bass Control > Off" in the purple case? If yes DL optimizes each sub individually and the combined result can lead to distortions like what you see in the purple curve. It has been discussed in this thread multiple times that this procedure is flawed and will ultimately result in an unpredictable and undesirable response. It's bad practice. Not sure why Dirac supports this in the first place.

Could also be a problem with your JBL/Arcam AVR. These units have had a plethora of firmware bugs. You would need to do more investigative measurements to get to the bottom of the issue.
 

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Sorry still don't understand exactly what your setup looks like and how you've performed measurements in REW.

Do you have 2 subs and you've selected "Bass Control > Off" in the purple case? If yes DL optimizes each sub individually and the combined result can lead to distortions like what you see in the purple curve. It has been discussed in this thread multiple times that this procedure is flawed and will ultimately result in an unpredictable and undesirable response. It's bad practice. Not sure why Dirac supports this in the first place.

Could also be a problem with your JBL/Arcam AVR. These units have had a plethora of firmware bugs. You would need to do more investigative measurements to get to the bottom of the issue.
I used L&R in REW, fronts with subwoofers. Measured together.

Yes, Bass control on. With both curves.
Had not have any problems before with the same procedure.
Could be with the calculation in Dirac since the crossovers are the same. 70 hz in both the dlbc measursements. 80 without Dirac.

Yes, but then it probably would have been with both.
 

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Discussion Starter #3,123
I used L&R in REW, fronts with subwoofers. Measured together.

Yes, Bass control on. With both curves.
Had not have any problems before with the same procedure.
Could be with the calculation in Dirac since the crossovers are the same. 70 hz in both the dlbc measursements. 80 without Dirac.

Yes, but then it probably would have been with both.
So you have 2 independend subs optimized with DLBC. When you measure with the default target curve you get the turquoise colored curve. When you measure with a custom target curve you get the purple curve. Correct? If yes then there's something broken.

Did you re-run BC calculations after applying the NAD curve?
Did you apply the NAD curve to all channels equally?
 

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So you have 2 independend subs optimized with DLBC. When you measure with the default target curve you get the turquoise colored curve. When you measure with a custom target curve you get the purple curve. Correct? If yes then there's something broken.

Did you re-run BC calculations after applying the NAD curve?
Did you apply the NAD curve to all channels equally?
Correct.

Yes, it does that automaticly.
Yes.
 

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Discussion Starter #3,125 (Edited)

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No. You have to recalculate. Maybe you're not using bass control and what you're seeing is the result of what I've described in this post?
It recalculates automaticly with any changes. But would try again later. :)
 

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Discussion Starter #3,127 (Edited)
It recalculates automaticly with any changes. But would try again later. :)
No. Only "Off" and "Upmix only" recalculate automatically. For "Full Bass Optimisation" you have to click the "Calculate" button at the bottom of the right-hand side.
 
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Is it possible to use 3 sub (2 i front and 1 back) , and get automatic full/good correction if you only use the Upmix mode..?
I have the JBL SDP55 .
 

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Discussion Starter #3,129
Is it possible to use 3 sub (2 i front and 1 back) , and get automatic full/good correction if you only use the Upmix mode..?
I have the JBL SDP55 .
Sure. Depending on the individual situation BC can improve on that. You would need to post DL results for all speaker groups for evaluation.
 

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Sure. Depending on the individual situation BC can improve on that. You would need to post DL results for all speaker groups for evaluation.
Ok , thankyou for replay :)
I plan to try maybe add a third sub behind the sofa , so it's good to know what's possible and not.

So far I have been mooe happy with the result doing upmix insted of full BC for some reason.
 

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Discussion Starter #3,131
Ok , thankyou for replay :)
I plan to try maybe add a third sub behind the sofa , so it's good to know what's possible and not.

So far I have been mooe happy with the result doing upmix insted of full BC for some reason.
Care to share some graphs from DL? The difference between "Upmix only" and "Full Bass Optimisation" should be readily apparent.
 

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Care to share some graphs from DL? The difference between "Upmix only" and "Full Bass Optimisation" should be readily apparent.
I have shared some graphs and questions about this earlyer in this tread. Post 2822 The official Dirac Live thread

I am not happy about what BC do in my system, but upmix works fine for me , so I just continue using Dirac in this mode I think.
 

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Discussion Starter #3,133

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I see, it already has been answered: The official Dirac Live thread
You would need to provide more data for a deeper evaluation.
No it's not .
Why dos BC increase GD so much..? That's the mainquestion - the difference in FR is not that important in this exemple above.
I've tried several times and I'm now using time refernce when measuring , and it's always the same result when it comes to GD..

Is this normal , or is it only me who have this experience...? If it's normal , it wouldn't be much point for me to do further investigation around this.
 

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Discussion Starter #3,135 (Edited)
No it's not .
Why dos BC increase GD so much..? That's the mainquestion - the difference in FR is not that important in this exemple above.
I've tried several times and I'm now using time refernce when measuring , and it's always the same result when it comes to GD..

Is this normal , or is it only me who have this experience...? If it's normal , it wouldn't be much point for me to do further investigation around this.
You didn't provide enough data yet. I highly doubt the rise in GD causes a significantly different perception. Rise in GD comes from filters. Here probably mainly from the all-pass filters.

Please show screenshots of the corrected responses in the DL filter design tab for all speaker pairs and both cases – "Upmix only" and "Full Bass Optimisation".
 

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Even though I frequently use REW to assess my setup's performance, I have rarely paid any attention to group delay. I don't think I understand the issue. How does group delay affect audio quality, and is increased GD audible?
 

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Discussion Starter #3,137
Even though I frequently use REW to assess my setup's performance, I have rarely paid any attention to group delay. I don't think I understand the issue. How does group delay affect audio quality, and is increased GD audible?
There have been a couple of studies and yes, excessive group delay can be audible. But, in most cases GD comes with frequency response distortion with the latter being highly audible while GD is not. Just because something is very visible in a graph doesn't mean it is audible.
 

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There have been a couple of studies and yes, excessive group delay can be audible. But, in most cases GD comes with frequency response distortion with the latter being highly audible while GD is not. Just because something is very visible in a graph doesn't mean it is audible.
I am seeing a difference in group delay with DLBC. Any guidelines that you are aware of WRT what would be considered "excessive"?

3077618
 

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You didn't provide enough data yet. I highly doubt the rise in GD causes a significantly different perception. Rise in GD comes from filters. Here probably mainly from the all-pass filters.

Please show screenshots of the corrected responses in the DL filter design tab for all speaker pairs and both cases – "Upmix only" and "Full Bass Optimisation".
I don’t have this now on this computer , so this must wait. But all the graphs in Dirac seems normal to me.
The sound is good also in with BC active , but the bass is a bit slower and more muddy.

But if it is becauce og the filtres then this should be normal for all users , not only me...?
If I am the only noe that have this experience , then I really have to digg deeper in this. But if this is an normal behaveior , I can just let it go...
That is my only question 😀
 
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