Exact -6db pan law (DONE)

hipass · 09-02-2015, 09:40 PM

This was mentioned as a feature request shortly before Nitpicks existed.

The -6db pan law should either not be coded in decibels, coded in decibels using the log form (20log2) or articulated to least three or four accurate figures, e.g. -6.021. The current -6.00 needlessly incurs minor changes to mono levels with any large pan movement. These changes occasionally warrant a tiny level revision, particularly if monitoring on an Auratone "grot box".

It shouldn't matter if -6.00 is a current standard, as the amplitude difference due to a rare problematic mismatch between old and new standards would only be as tiny as those which are just bothersome in virtue of being forever ongoing with the current mixing implementation.

VinodXAgent · 09-04-2015, 01:19 PM

If your room is not that good try to work with -3 dB Pan-Law.
Vinod

hipass · 09-07-2015, 12:59 AM

I set levels in mono, usually with an Auratone 5c single driver monitor, to avoid point-source issues, among other things. The room makes no difference in this context. I only monitor in stereo to set pan positions, and it's an advisable method that many others use too. With a perfect -6.021 implementation, no stereo pan adjustments would make any difference at all to the mono levels, which is the basic point of the -6db law.

Pook2000 · 09-07-2015, 03:43 AM

Quote:

Originally Posted by hipass

I set levels in mono

So would this result in one not having to worry about pan law at all? If you mix mostly in mono, set your levels, pan later, the levels then have already been decided during the mono phase of your mix? So you have nothing to worry about regards pan law?

This approach interests me very much.

ramses · 09-07-2015, 06:01 AM

I have a hard time imagining that a .021 dB difference would be audible in the mix anyway. Are you absolutely certain that you are able to discern this? I'm not trying to slag you off here, but it seems unlikely to me, that's all. I would first test this with a decent ABX comparator to make sure I'm not imagining things, but that's me...

hipass · 09-07-2015, 06:03 AM

Setting levels in mono and panning later can only work with the -6db pan law (and would only work perfectly with -6.021), because panning under every other law changes the overall amplitude.

hipass · 09-07-2015, 06:20 AM

The maximum amplitude difference between 12bit and 16bit versions of the same recording is .017db and it's audible in all kinds of ways to most people.

Admittedly, that's a lively difference, but so are the relative levels of transients and the ever-changing perceived presence of any two tracks.

But really the burden of proof should be the other way around, since changing one little number in the code secures theoretical perfection.

Dstruct · 09-07-2015, 06:58 AM

Did you test it? Maybe the display just says 6dB while it's processing -6.021dB!?

LightOfDay · 09-07-2015, 07:02 AM

Quote:

Originally Posted by hipass

The maximum amplitude difference between 12bit and 16bit versions of the same recording is .017db and it's audible in all kinds of ways to most people.

12bit???

and no, 0.017 are not audible.

hipass · 09-07-2015, 07:43 AM

I did test it, hoping that it was just my imagination causing me to think that the mono levels needed readjustment after panning. The difference in software-measured levels between a mono sum recording of hard panned mono track and the un-panned mono sum was .02dB.

LightofDay, there used to be 12bit samplers, even 8bit, and the difference between those was even more obvious than the difference between 12 and 16 (or 16 and 20, or 20 and 24, etc.) even though the dynamic window between them in each case is still .017 dB. It's just more in your face with lower bit rates since the 24dB difference in dynamic range is then a bigger proportion of the total dynamic range.

Aeolian · 10-28-2015, 02:49 PM

24bit = 144db of DR (in theory)
16bit = 96dB of DR
12bit = 72dB of DR
8bit = 48dB of DR

I'm pretty curious how you derived a .017dB in DR between 12bit and 16bit.

Dstruct · 02-23-2016, 04:27 PM

Check 5.20pre9, might be "fixed" there:

Quote:

+ Panning: optimize pan law calculation, improve rounding

Justin · 03-02-2016, 09:33 AM

Quote:

Originally Posted by Dstruct

Check 5.20pre9, might be "fixed" there:

Probably not, but we'll add a -6.02dB mode soon, for those who are anal about such things!

Justin · 03-02-2016, 09:44 AM

Quote:

Originally Posted by Aeolian

24bit = 144db of DR (in theory)
16bit = 96dB of DR
12bit = 72dB of DR
8bit = 48dB of DR

I'm pretty curious how you derived a .017dB in DR between 12bit and 16bit.

Perhaps they were suggesting that a .02dB difference is representable at the top of a 12 bit scale (the difference between +2046 and +2047), maybe?

LightOfDay · 03-02-2016, 09:50 AM

Quote:

Originally Posted by Justin

Probably not, but we'll add a -6.02dB mode soon, for those who are anal about such things!

optional in the preferences?

Dstruct · 03-05-2016, 12:26 PM

DONE (5.20pre15)

http://forum.cockos.com/showthread.php?t=173807

hipass · 05-07-2016, 06:26 AM

Measured difference is zero, to arbitrary decimal places. I have to call that nice work even if someone had to call me anal.

To the query about .017db, that is half the sum of 0db and -48db (limit of 8 bit resolution), i.e., the loudest addition (saving the other half for reduction) of the lowest 24db of dynamic range at 12bit.

09-02-2015, 09:40 PM	#1
hipass Human being with feelings Join Date: Aug 2015 Posts: 9	Exact -6db pan law (DONE) This was mentioned as a feature request shortly before Nitpicks existed. The -6db pan law should either not be coded in decibels, coded in decibels using the log form (20log2) or articulated to least three or four accurate figures, e.g. -6.021. The current -6.00 needlessly incurs minor changes to mono levels with any large pan movement. These changes occasionally warrant a tiny level revision, particularly if monitoring on an Auratone "grot box". It shouldn't matter if -6.00 is a current standard, as the amplitude difference due to a rare problematic mismatch between old and new standards would only be as tiny as those which are just bothersome in virtue of being forever ongoing with the current mixing implementation.

09-07-2015, 12:59 AM	#3
hipass Human being with feelings Join Date: Aug 2015 Posts: 9	I set levels in mono, usually with an Auratone 5c single driver monitor, to avoid point-source issues, among other things. The room makes no difference in this context. I only monitor in stereo to set pan positions, and it's an advisable method that many others use too. With a perfect -6.021 implementation, no stereo pan adjustments would make any difference at all to the mono levels, which is the basic point of the -6db law. Last edited by hipass; 09-07-2015 at 02:22 AM.

09-07-2015, 06:20 AM	#7
hipass Human being with feelings Join Date: Aug 2015 Posts: 9	The maximum amplitude difference between 12bit and 16bit versions of the same recording is .017db and it's audible in all kinds of ways to most people. Admittedly, that's a lively difference, but so are the relative levels of transients and the ever-changing perceived presence of any two tracks. But really the burden of proof should be the other way around, since changing one little number in the code secures theoretical perfection. Last edited by hipass; 09-07-2015 at 06:27 AM.

10-28-2015, 02:49 PM	#11
Aeolian Human being with feelings Join Date: Jun 2010 Location: Somewhere PRO Posts: 1,049	24bit = 144db of DR (in theory) 16bit = 96dB of DR 12bit = 72dB of DR 8bit = 48dB of DR I'm pretty curious how you derived a .017dB in DR between 12bit and 16bit. __________________ "REAPER... You're simply the best" - Tina Turner

05-07-2016, 06:26 AM	#17
hipass Human being with feelings Join Date: Aug 2015 Posts: 9	Thanks Measured difference is zero, to arbitrary decimal places. I have to call that nice work even if someone had to call me anal. To the query about .017db, that is half the sum of 0db and -48db (limit of 8 bit resolution), i.e., the loudest addition (saving the other half for reduction) of the lowest 24db of dynamic range at 12bit. Last edited by hipass; 05-07-2016 at 10:40 PM.

09-04-2015, 01:19 PM	#2
VinodXAgent Human being with feelings Join Date: Nov 2013 Location: Hamburg Posts: 749	If your room is not that good try to work with -3 dB Pan-Law. Vinod

09-07-2015, 06:01 AM	#5
ramses Human being with feelings Join Date: Jul 2009 Posts: 1,236	I have a hard time imagining that a .021 dB difference would be audible in the mix anyway. Are you absolutely certain that you are able to discern this? I'm not trying to slag you off here, but it seems unlikely to me, that's all. I would first test this with a decent ABX comparator to make sure I'm not imagining things, but that's me...

09-07-2015, 06:03 AM	#6
hipass Human being with feelings Join Date: Aug 2015 Posts: 9	Setting levels in mono and panning later can only work with the -6db pan law (and would only work perfectly with -6.021), because panning under every other law changes the overall amplitude.

09-07-2015, 06:58 AM	#8
Dstruct Human being with feelings Join Date: Jul 2006 Posts: 12,525	Did you test it? Maybe the display just says 6dB while it's processing -6.021dB!?

09-07-2015, 07:43 AM	#10
hipass Human being with feelings Join Date: Aug 2015 Posts: 9	I did test it, hoping that it was just my imagination causing me to think that the mono levels needed readjustment after panning. The difference in software-measured levels between a mono sum recording of hard panned mono track and the un-panned mono sum was .02dB. LightofDay, there used to be 12bit samplers, even 8bit, and the difference between those was even more obvious than the difference between 12 and 16 (or 16 and 20, or 20 and 24, etc.) even though the dynamic window between them in each case is still .017 dB. It's just more in your face with lower bit rates since the 24dB difference in dynamic range is then a bigger proportion of the total dynamic range.

03-05-2016, 12:26 PM	#16
Dstruct Human being with feelings Join Date: Jul 2006 Posts: 12,525	DONE (5.20pre15) http://forum.cockos.com/showthread.php?t=173807

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