# Loudness curve needed for home mixes?



## Drudge (Sep 1, 2008)

Does a movie(Blu-ray/DVD)mixed for home playback need loudness curve compensation?

I know that Disney mixes their BD/DVD releases for home playback and you don't need to engage the Re-EQ function,but is there any loudness compensation that might already be applied to the home release to compensate for the lower than 'reference level' that most in the home listen at? 

Is there any reason not to use a loudness contour with a home mix?


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## mechman (Feb 8, 2007)

Would this be a REW related type of question? OR maybe a receiver type question? I'm a bit unsure where this thread should go. :scratch:


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## eugovector (Sep 4, 2006)

If you have Audyssey Dynamic EQ or something similar built into your AVR, that's it.


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## Drudge (Sep 1, 2008)

I don't have Audyssey DEQ,but I do have my system calibrated with Audyssey Pro and the SEQ.I have a MC-12 which has Lexicon's own proprietary loudness compensation(which isn't based exactly on the FM or RD equal loudness curves) contour,it's not as advanced as the Audyssey DEQ,in the fact that it doesn't do real time analyzing of the source material and perform spectral correction based on that and the main volume setting.

The MC-12 contour changes are fixed curves that change with the volume knob adjustments.

I'm just curious if the mixes meant for the home have any type of contour applied to them to make them sound more balanced at the lower than reference volume levels that most people listen at.


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## Wayne A. Pflughaupt (Apr 13, 2006)

If your system is calibrated for both your room and your normal listening level, then no compensation is necessary. That would only come into play if you decide to listen at levels lower or higher than your normal level.

Regards,
Wayne


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## jaddie (Jan 16, 2008)

Drudge said:


> I don't have Audyssey DEQ,but I do have my system calibrated with Audyssey Pro and the SEQ.I have a MC-12 which has Lexicon's own proprietary loudness compensation(which isn't based exactly on the FM or RD equal loudness curves) contour,it's not as advanced as the Audyssey DEQ,in the fact that it doesn't do real time analyzing of the source material and perform spectral correction based on that and the main volume setting.
> 
> The MC-12 contour changes are fixed curves that change with the volume knob adjustments.
> 
> I'm just curious if the mixes meant for the home have any type of contour applied to them to make them sound more balanced at the lower than reference volume levels that most people listen at.


The problem with a fixed loudness curve is that it 's only right at one specific SPL. You can't derive SPL from a knob setting, it's changing with program material. So any fixed curve applied at any time will not be correct except for moments when the specific SPL matches that for which the curve was developed. That's assuming the correct loudness curve to begin with. It would be foolish for studios to remaster with an assumed, fixed loudness compensation curve built in. Most home video specific mastering addresses two areas: total dynamic range (home mixes are more restricted), and playback in a room without the X-curve, which results in the theoretical elimination of the need for re-eq (thus creating a new nightmare). Not to say that some remastering doesn't include some sort of EQ based on the assumption that home playback is 8 to 10 dB lower than theatrical, but it would be a rather misguided and futile attempt.

Calibrating your room at your normal listening level won't properly correct for a lower playback level, because the correction curve must change dynamically. 

There are three major systems that address dynamic loudness correction: Dolby Volume, THX Loudness Plus, and Audyssey Dynamic EQ. Of the three, only one actually knows the moment to moment SPL (Audyssey), the other two assume based on a knob setting. Only one was created by reverse-engineering human loudness response, again, Audyssey, the others are based on published curves. All three adjust LCR to Surround balance dynamically, but only Audyssey does this by responding to actual in-room levels, the others use an arbitrary compression algorithm.


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## Mark Techer (Jan 17, 2008)

Wayne A. Pflughaupt said:


> If your system is calibrated for both your room and your normal listening level, then no compensation is necessary. That would only come into play if you decide to listen at levels lower or higher than your normal level.


Which is what THX LOUDNESS PLUS is all about.


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## Roger Dressler (Aug 1, 2009)

Drudge said:


> I'm just curious if the mixes meant for the home have any type of contour applied to them to make them sound more balanced at the lower than reference volume levels that most people listen at.


No.


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