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X-curve compensation re-EQ

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I thought WW was well done but prob could use a little BEQ, but not much.  It was very similar to Man of Steel  in the LFE channel, IIRC.  I'll look at it when I get a chance.

Loved the film.  Closest the DC Universe has come to approaching Marvel quality (Batman Begins and The Dark Knight excepted).  Reminded me a lot of Thor, with the 'fish out of water' plotline.

JSS

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Soo...

 

I had a talk with my friend who mixes feature films for a living.

http://www.imdb.com/name/nm0279892/?ref_=fn_al_nm_1

The "x-curve" does still exist, I was wrong there. But... it is not a part of the mix. The compensation for the screen and losses from distance are done during the calibration of the system, per screen. There is no EQ done and it is not a mandate for the home "nearfield" mixes that anything of the sort is applied to the mix itself. Minor adjustments to levels to surrounds and dialog (~1dB deviation from theatrical) are about as offensive as it gets.

 

Sorry to burst yer bubble but.... ;)

 

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Infrasonic, can I get your friend's address so I can send a 24 so your friend can learn to mix the feature films CORRECTLY. :) 

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Just checked some new movies, to verify they will play, and always curious about the sound. 

In one they got the low freqs right, amazing how the very last octave has so huge effect on the overall experience. But since I rarely watch movies these days, the "movie-sound" dialogue is apparent once they start talking - it booms, and the upper freq range has a very strange tonal character.

So re-eq for the rest, doing not only the bass-eq, certainly makes sense.

The problem is to know the eq profile. Doing this properly, for each movie, is just too much work just to watch a movie.

But is it possible to do it right, so that voices have a natural tonal balance, without the excessive boom and strange nasality? Perhaps my speakers are wrong?

Vocal in music does not sound like this, and a typical well-made documentary usually sounds very good. So it is definitely possible, and the problem is how the sound is made in the movies.

The best solution would be if the movies were properly made - no low bass cut to adapt to bass studio and cinema speaker systems, and tonal balance that sounds natural on a reasonably flat system.

The next best would be if they could provide a eq profile with the movie, so that it is possible to apply the necessary re-eq with reasonable effort.

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9 hours ago, Infrasonic said:

Minor adjustments to levels to surrounds and dialog (~1dB deviation from theatrical) are about as offensive as it gets.

Audyssey's Dynamic EQ may do more that that...

Best news I have heard in a while; possibly confirmed by my experience with Star Wars:The Last Jedi, where I guessed the level of playback on an opening night showing within 0.5 'units' on the Dolby Box (confirmed by the theater's general manager).   Good to know the theatrical/home mixes aren't substantially different at Technicolor (still where FilmMixer is at?).

JSS

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7 hours ago, Infrasonic said:

A single sealed 24 for a full sized cinema auditorium?

What could go wrong?

:P

 

But if you'd like to make an offer... he goes by FilmMixer at AVS. PM him.

For the mixing/studio room silly. :)  But hey, most theaters only do 30Hz and up so maybe a single ported 24 would be plenty. :)

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13 hours ago, Infrasonic said:

I had a talk with my friend who mixes feature films for a living.

http://www.imdb.com/name/nm0279892/?ref_=fn_al_nm_1

It appears you mean @FilmMixer  Yes.  He even has an account here.  I remember him posting a bit about Fury and also answering questions about whether bass filters get applied during the production process.

13 hours ago, Infrasonic said:

The "x-curve" does still exist, I was wrong there. But... it is not a part of the mix. The compensation for the screen and losses from distance are done during the calibration of the system, per screen.

It's essential to distinguish between the X-curve target and the X-curve calibration process.  The X-curve calibration process fits the continuous pink noise response measured at the listening position to the X-curve target.

The X-curve calibration process involves EQing the system across its full-bandwidth, and this process compensates for screen and distance losses.

As for whether the X-curve is part of the mix, however, the answer is a lot more complicated then "yes" or "no".  Strictly speaking, neither the X-curve target nor its inverse is applied directly to the mix.  So in that sense, I agree that the X-curve target is not a part of the mix.

However, the X-curve calibration process causes the tonal balance response on the dub-stage to be skewed.  The precise shape of the skew varies between systems, but they share common characteristics: attenuated highs and attenuated lows, relative to a neutral system based on anechoic flat (with smooth off-axis) speakers and no screen effects.  As such, the shape of the subjective tonal balance response curve looks rather unlike the X-curve target itself.

So even if mixers were to try to reverse the effect of X-curve calibration, the inverse of the X-curve target would be the wrong curve to apply.  In all likelihood, mixers aren't thinking about X-curve effects when they do their mixes at all.  They are simply trying to craft a mix with the best sound possible.  EQ is but one of many tools that are likely used on the dub stage to do this.  It would likely to used extensively even if dub-stages were perfectly neutral.  However, unless the mixers are aware of the effects of the X-curve calibration and consciously avoid mixing "through them", the tonal balance skew of the dub-stage will ultimately affect the sound of the mix.

13 hours ago, Infrasonic said:

There is no EQ done and it is not a mandate for the home "nearfield" mixes that anything of the sort is applied to the mix itself. Minor adjustments to levels to surrounds and dialog (~1dB deviation from theatrical) are about as offensive as it gets.

I assume you mean to say here that no EQ is done on home mixes.  I presume EQ is almost always used extensively for the original mix on the dub-stage.

Even still, I seriously doubt that your statements here are true in general.  They may be true for @FilmMixer and how he approaches home mixes but his approach may not be representative of how other home mixes are done.  My guess, based partly on what I hear, is that home mixing practices vary all over the place.  I'd bet that many home mixes are being re-EQed in some fashion.  Furthermore, many are being subject to significant dynamics processing, for better or worse.

Furthermore, I don't consider deviations from the cinema track to be offensive.  I'm not a purist in any sense.  I just want excellent sound quality for my high performing home system, whatever that takes.  I have no desire to duplicate the cinema experience, as it exists now.  Even ignoring bass performance differences, my home system sounds leaps and bounds better when playing back high quality home mixes, presumably those that were re-EQed while being monitored on high-quality neutral speakers in a high quality small-room listening environment vs. a near-field or acoustically dead environment.

13 hours ago, Infrasonic said:

Sorry to burst yer bubble but.... ;)

No bubbles are being burst here.  Maybe I'm all wrong in my justification for doing this, but I can state with confidence that the re-EQ I do provides better sound.  It's not silly subtle audiophile stuff.  It's plain-as-day improvement on titles that need it, even when using fairly generic / coarse corrections.  The opinion(s) of one or more film mixers aren't going to make me change my practice, but they may make me feel disappointed that others are not able to hear these soundtracks at their best.

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I gave the correction a try on a few scenes, bit of a mixed bag tbh. Effects noticed included;

Voices in some scenes were more natural  (less full/warm) though were also less obviously the focus of the scene.

Some scenes took on a certain hollowness/metallic tang which was similar to a sound ISTR from one particular EQ which went wrong and was doing something excessive around 1kHz. 

Some scenes, which involved more ambient noise, were less engaging as if the track had receded into the distance.

I tried ~4-5 scenes (a couple from the island stage, a couple from the later ww1 bit) and a few had fairly inconsequential differences, the 2 that stood out more were the scene in the castle when he tries to chat to the chemist (ambient voices as he walks up to her were receded, their voices were less pronounced but more natural) and the scene when the young diana is asking her mum to let her train and her mum is going on about moulding her out of clay (metallic tang).

I'm afraid I couldn't trial this over a prolonged slice of film because I thought the film itself was borderline terrible which was a surprise given the reviews. I thought it had a bizarrely disjointed storyline that felt like they mashed 3 different films together and was at least 30mins too long. The love story angle was pretty sad too given the main character & the seriousness with which they played the film given the storyline was rather odd. 

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13 hours ago, maxmercy said:

Audyssey's Dynamic EQ may do more that that...

Best news I have heard in a while; possibly confirmed by my experience with Star Wars:The Last Jedi, where I guessed the level of playback on an opening night showing within 0.5 'units' on the Dolby Box (confirmed by the theater's general manager).   Good to know the theatrical/home mixes aren't substantially different at Technicolor (still where FilmMixer is at?).

JSS

That's my point. The difference between the mixing stage and our homes is wildly different.

We keep constantly trying to justify things we do/believe about how we hear things at home and compare it to how things work in a large acoustic space to our living rooms or even how the things we hear are made in the first place.

It must also be made clear what Marc does. He is a Re-recording Mixer. That is, the guy who gets all the stuff at the end and makes sure it works. *insert snarky comment about mixes not working cuz not enough bass or something* He doesn't create the effects. He's not the guy "making the bass". He is making sure all the elements are where they need to be and the levels between them are good. At no point is he EQ'ing anything. There are engineers working alongside (or at other times) that would have done that. So you have to understand when I ask him questions, it's coming from his PoV. There will always be a disconnect between what he does and what we demand as end users. Though his passion outside of work is no different from us. He loves consumer A/V equipment just like us.

Not sure how he'd feel about telling people where or what he is working on currently so I'm going to skip that part. Just not sure if I should give out other peoples personal info, I mean. Apparently he did post here so I'll leave it to him to reply about what he is doing right now.

12 hours ago, dgage said:

For the mixing/studio room silly. :)  But hey, most theaters only do 30Hz and up so maybe a single ported 24 would be plenty. :)

His mixing/studio room IS a full sized cinema auditorium though. ;)

Even a single ported 24 would have a lot of work to do.

Do you make a ported 24 now? I'd like to see that, fo sho! :)

7 hours ago, SME said:

I assume you mean to say here that no EQ is done on home mixes.  I presume EQ is almost always used extensively for the original mix on the dub-stage.

Right.

There is no part in his workflow where he "EQ's" the sound. Somebody else has already done that by the time he gets it.

Also, multiple mixes are made for a movie for various reasons. Comparing one mix to another usually leads to confusion and it should because nobody here created them.

7 hours ago, SME said:

Even still, I seriously doubt that your statements here are true in general. 

 

Well, there ya go.

 

7 hours ago, SME said:

 

They may be true for @FilmMixer and how he approaches home mixes but his approach may not be representative of how other home mixes are done. 

Obviously. You should retain this statement in your head and really remember it. :P

7 hours ago, SME said:

My guess, based partly on what I hear, is that home mixing practices vary all over the place. 

Yes. The illusion we put upon ourselves is that following standards will "level the playing field" but that is not the case in reality.

7 hours ago, SME said:

I'd bet that many home mixes are being re-EQed in some fashion. 

Yes, of course. That is how they sound how they sound. Everything that is sound that isn't pure untouched recordings of life, are artificially made. Creations born out of a computer or mixing board. There is nothing "pure" in the music we listen to and especially the movies we watch.

7 hours ago, SME said:

 

Furthermore, many are being subject to significant dynamics processing, for better or worse.

That goes without saying for everything that is produced.

7 hours ago, SME said:

Furthermore, I don't consider deviations from the cinema track to be offensive.  I'm not a purist in any sense.  I just want excellent sound quality for my high performing home system, whatever that takes.

We all do and we all have our own opinion on how it should be done. ;)

7 hours ago, SME said:

 

  I have no desire to duplicate the cinema experience, as it exists now.  Even ignoring bass performance differences, my home system sounds leaps and bounds better when playing back high quality home mixes, presumably those that were re-EQed while being monitored on high-quality neutral speakers in a high quality small-room listening environment vs. a near-field or acoustically dead environment.

Presumably.

7 hours ago, SME said:

No bubbles are being burst here.  Maybe I'm all wrong in my justification for doing this, but I can state with confidence that the re-EQ I do provides better sound.  It's not silly subtle audiophile stuff.  It's plain-as-day improvement on titles that need it, even when using fairly generic / coarse corrections.  The opinion(s) of one or more film mixers aren't going to make me change my practice, but they may make me feel disappointed that others are not able to hear these soundtracks at their best.

Yes, of course. To achieve the best sound, you should EQ to personal taste. ;)

...to personal taste.

 

......to personal taste.

 

:P

 

 

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12 hours ago, Kvalsvoll said:

Just checked some new movies, to verify they will play, and always curious about the sound. 

In one they got the low freqs right, amazing how the very last octave has so huge effect on the overall experience. But since I rarely watch movies these days, the "movie-sound" dialogue is apparent once they start talking - it booms, and the upper freq range has a very strange tonal character.

So re-eq for the rest, doing not only the bass-eq, certainly makes sense.

The problem is to know the eq profile. Doing this properly, for each movie, is just too much work just to watch a movie.

But is it possible to do it right, so that voices have a natural tonal balance, without the excessive boom and strange nasality? Perhaps my speakers are wrong?

Vocal in music does not sound like this, and a typical well-made documentary usually sounds very good. So it is definitely possible, and the problem is how the sound is made in the movies.

The best solution would be if the movies were properly made - no low bass cut to adapt to bass studio and cinema speaker systems, and tonal balance that sounds natural on a reasonably flat system.

The next best would be if they could provide a eq profile with the movie, so that it is possible to apply the necessary re-eq with reasonable effort.

Yes.  If your speakers are reasonably accurate, the difference in human vocals and dialog between typical cinematic content and music will be glaringly apparent.  On my system, vocals sound very natural with a wide variety of music including stuff that was probably mixed and even mastered in a tiny room in someone's basement.  Yet many if not most movie soundtracks, including many with multi-100-million-dollar budgets, often have weird, unnatural sounding dialog.  Obviously something is seriously wrong with the movie mixes, and it's not something that can be fixed merely by manipulating levels or applying dynamic range compression.

You also note that well-made documentaries usually sound good.  And in fact, I find that a lot of lower-budget indie-films also sound very good.  How ironic that lower budget films, made by people who probably couldn't afford to rent out a dub-stage, are able to deliver more natural sounding dialog (albeit in the home and not so much the cinema) than big-budget Hollywood flicks.  It's utterly tragic, especially considering how important dialog is to the art itself.  In the 21st century, we shouldn't even have to discuss the issue of dialog intelligibility.  Instead, we should be talking about how well the dialog reproduction conveys the nuances of the actor/actresses voices, or whether it adequately conveys the emotional messages, beyond mere words.  Yet cinema audio dialog routinely fails to convey these details in most cinemas while often failing to even be intelligible in the home.

I don't really blame the mixers for this.  Their job is to do the best they can do with the tools they have, and they must do so under intense pressure and an accelerated time-schedule.  They have to work with the monitoring system on the dub-stage as-is, even it the tonal balance is skewed.  They are also not in a position to develop better standards, which involves a lot more work than simply identifying that there is a problem.

I agree with your "best" solution above.  Cinema mixes should be monitored on a system whose tonal balance is consistent with a reasonably flat home system.  The problem is that the screen adds a variable high frequency loss to the speaker response, which makes it impossible to achieve this goal by simply installing high quality / flat monitors and abandoning the X-curve calibration standard.  Furthermore, it's reasonable to expect some subjective low frequency response variation to remain, despite the use of flat monitors.

What's needed is a calibration method that relies on impulse response measurements, preferably at multiple measurement locations, and corrects the aspect(s) of the IRs that are directly relevant to tonal balance perception.  To do so requires a method of analyzing and reducing the IR data to obtain level vs. frequency data that directly relates to subjective tonal balance.  I don't believe such an analysis method is widely available yet, but it's possible to get close by comparing magnitude-smoothed response to a target curve , one which is likely to look more similar to the Harman target curve than the X-curve target.  Such an approach won't do much to reduce variation between dub-stages and cinemas, but it will bring dub-stages and cinemas a lot closer to home systems.

Note that your "next-best" solution also requires a method of analyzing and reducing the IR data to obtain level vs. frequency data the directly relates to subjective tonal balance.  And it furthermore requires studios to publish IR measurements of their dub-stages.  I'd actually be quite happy if they performed such measurements and published them because it would help me better understand what's going on in those spaces.

It turns out that some IR measurements of cinemas and dub-stages have been recently done and results were published here.  But unfortunately, the publication leaves a lot of open questions.  For one, they did not publish the raw IR data and only published analyzed/reduced information using analysis methods that I find only marginally interesting.  Furthermore, instead of using a high quality sine-sweep measurement system like REW, they relied on a home-brew system that used a continuous pink noise signal and apparently suffered from a very poor signal-to-noise ratio.  That is a big problem because much of the late arriving energy in larger rooms such as these will be from low level reverb.  This sound can considerably inflate power-averaged pink noise measurements even though it may do relatively little to affect tonal balance perception, which is why it's important to capture that part of the response accurately in order to understand what X-curve calibration is actually doing.

Still, there are certain characteristics that X-curve calibrated systems share in common, and it is possible to correct for those common characteristics.  I find a -2 dB/octave high frequency slope works fairly well with a lot of material, but it must always be used together with a low frequency shelf.  A decent starting point on the low end may be a Low Shelf at f0=250.0, Q=0.625, gain=-4.0.  Those two corrections are likely to be a step in the right direction, though a long way off from being ideal.  To me, generic corrections like these yield sound that's comparable to a "good" cinema, which shouldn't be surprising.  Of course, these filters will work a lot better with some films than others, and it's usually beneficial to make additional adjustments.

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8 hours ago, 3ll3d00d said:

I gave the correction a try on a few scenes, bit of a mixed bag tbh. Effects noticed included;

Voices in some scenes were more natural  (less full/warm) though were also less obviously the focus of the scene.

Some scenes took on a certain hollowness/metallic tang which was similar to a sound ISTR from one particular EQ which went wrong and was doing something excessive around 1kHz. 

Some scenes, which involved more ambient noise, were less engaging as if the track had receded into the distance.

I tried ~4-5 scenes (a couple from the island stage, a couple from the later ww1 bit) and a few had fairly inconsequential differences, the 2 that stood out more were the scene in the castle when he tries to chat to the chemist (ambient voices as he walks up to her were receded, their voices were less pronounced but more natural) and the scene when the young diana is asking her mum to let her train and her mum is going on about moulding her out of clay (metallic tang).

I'm afraid I couldn't trial this over a prolonged slice of film because I thought the film itself was borderline terrible which was a surprise given the reviews. I thought it had a bizarrely disjointed storyline that felt like they mashed 3 different films together and was at least 30mins too long. The love story angle was pretty sad too given the main character & the seriousness with which they played the film given the storyline was rather odd. 

Big thanks for giving it a try and offering your feedback!  I'm sorry to hear you didn't like the movie, and I gather that it means that you will be reluctant to re-evaluate the track if I were to suggest a different re-EQ profile to try.  I must admit, I probably shouldn't have posted a configuration or asked for serious feedback until I'd spent a bit more time getting it "right".

I do want to ask you a few questions to better establish context for your comments:

  • Did you implement the JRiver coefficients that you posted here (what I'm calling "v1")?  Or did you calculate new JRiver coefficients, based the updated "v2" config I posted afterwards?
  • What playback level (approximately) did you use to evaluate?
  • How are your speakers calibrated?  Do you use Acourate?  And if so, what kind of target curve do you use for the high frequencies?  Or did you use outdoor / anechoic polar response measurements?

Assuming you evaluated the "v1" configuration, I'm not surprised you heard some upper-mid ringing.  I plotted a comparison of "v1" and "v2", and you can see that "v1" has a sharper peak around 1.9 kHz and a bit more emphasis overall in the 1.5-2kHz range compared to "v2".  I did further work but have yet to publish a "v3" configuration, which emphasizes 1-2 kHz even less.  I hope to take the time to put some finishing touches on v3 this week, so that it is (hopefully) the last revision I publish.

I am a bit surprised that you don't report the reduced brightness to be a positive.  I found a lot of dialog and effects to be quite fatiguing without the re-EQ.  Though how one will experience those things tends to depend a lot on both playback level and calibration method / target.  That is why I'm asking about those things.

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I wouldn't watch the whole film again, don't mind trying some specific scenes though.

>> Did you implement the JRiver coefficients that you posted here (what I'm calling "v1")?  Or did you calculate new JRiver coefficients, based the updated "v2" config I posted afterwards?

the v1 ones

>> What playback level (approximately) did you use to evaluate?

-7

>> How are your speakers calibrated?  Do you use Acourate?  And if so, what kind of target curve do you use for the high frequencies?  Or did you use outdoor / anechoic polar response measurements?

current target rises ~5dB from 125Hz down to 25Hz and is basically flat above that, the correction switches at about 900Hz to an anechoic only correction (based on measurements taken outdoor from 0-60 degrees). The speaker itself is maybe 1dB down from 1-16kHz on axis, graphs in http://www.avsforum.com/forum/155-diy-speakers-subs/2188265-attempting-3way-seos10.html#post54724444

 

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5 hours ago, Infrasonic said:

His mixing/studio room IS a full sized cinema auditorium though. ;)

Even a single ported 24 would have a lot of work to do.

Do you make a ported 24 now? I'd like to see that, fo sho! :)

Haha.  No to a ported 24.  I don’t want to deal with moving and shipping huge refrigerators. :)  

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12 hours ago, Infrasonic said:

That's my point. The difference between the mixing stage and our homes is wildly different.

We keep constantly trying to justify things we do/believe about how we hear things at home and compare it to how things work in a large acoustic space to our living rooms or even how the things we hear are made in the first place.

Yes they are wildly different.  But what if dub-stages were optimized for a flat direct sound response (excepting a bass rise under 100-200 Hz or so), consistent with how home systems typically perform, instead of calibrating to the X-curve standard.  Just how many of those remaining differences would be perceptually relevant?  I think that while some perceptual differences would remain, they would be minuscule in comparison.

Scientific evidence strongly suggests that our brains are highly adaptive to different acoustic environments and attempt to deduce the sound of the source independently of the environment.  That doesn't mean that the acoustic environment has no perceptual effect at all, but rather, the influence of the acoustic environment is perceived independently from our perception of the source sound.  The exception to this is that early reflections in small rooms do influence perception of the source, which is why it's important to either: (1) use speaker with good off-axis response in addition to good on-axis response (preferable); or (2) absorb all the early reflections to prevent the ugly off-axis sound from reaching your ears in the first place.

This means that what matters most to perception is the sound that the speaker is making, possibly filtered by the screen material in front.  Recent measurements of anechoic flat speakers in cinemas indicate that they exhibit an in-room frequency response that is much more similar to the Harman curve than anything like the X-curve target.  The response actually looks vaguely similar to what may be measured from a similar speaker in a *much smaller room*.

So while the differences between the acoustics of the two rooms may be substantial, the relevance to perception is likely to be much less than most people believe.  I'd guess that the differences in direct sound response between dub stages and home theaters accounts for 80-90% of the perceived difference in sound between those environments.  In fact, if cinemas were calibrated accurately to match the direct sound response of small room systems, it would probably make far more sense to prepare movie mixes in a small room studio and only use the dub-stage for a final run-through.

14 hours ago, Infrasonic said:

It must also be made clear what Marc does. He is a Re-recording Mixer. That is, the guy who gets all the stuff at the end and makes sure it works. *insert snarky comment about mixes not working cuz not enough bass or something* He doesn't create the effects. He's not the guy "making the bass". He is making sure all the elements are where they need to be and the levels between them are good. At no point is he EQ'ing anything. There are engineers working alongside (or at other times) that would have done that. So you have to understand when I ask him questions, it's coming from his PoV. There will always be a disconnect between what he does and what we demand as end users. Though his passion outside of work is no different from us. He loves consumer A/V equipment just like us.There is no part in his workflow where he "EQ's" the sound. Somebody else has already done that by the time he gets it.

[...]

22 hours ago, SME said:

I assume you mean to say here that no EQ is done on home mixes.  I presume EQ is almost always used extensively for the original mix on the dub-stage.

Right.

There is no part in his workflow where he "EQ's" the sound. Somebody else has already done that by the time he gets it.

Also, multiple mixes are made for a movie for various reasons. Comparing one mix to another usually leads to confusion and it should because nobody here created them.

I'm not sure what you are saying here.  Does he use EQ while working on the dub-stage or not?  EQ is widely used as a general purpose tool in the process of preparing audio mixes in general.  I'm fairly sure that the vast majority of mixers use EQ as one of many tools in the mixing process.  Even if the samples tracks being mixed sound pristine when listened to in isolation, the total mix usually sounds better if EQ is skull-fully applied to the individual parts.  The reason for this has to do with psychoacoustic masking.  Whenver multiple parts have sound within the same frequency range, the one with higher SPL will tend to mask the  other, and if the SPL is roughly matched, the intelligibility of both will be compromised.  As such, mixers often use EQ to ensure that each part is dominates its own band(s) of frequencies to make it easier to perceive all the parts simultaneously.

To give an example of potential relevance to movies.  A scene may call for the score or music to be playing loud while crucial dialog is being spoken.  The most important frequencies for dialog by far are in the mid-range, so the mixer may attenuate the mid-range in the music to allow the dialog to "punch through".  Likewise, the mixer may also cut the highs and lows of the dialog a bit to allow the music to perceived more easily too.

The above example is actually very interesting if you think about what happens if the tonal balance of the presentation on playback is skewed, relative to the monitoring conditions that were used to create the soundtrack.  Suppose the the high and low frequencies are boosted and the mid frequencies are attenuated, which is exactly what I contend happens when typical cinema soundtracks are played on neutral home systems.  Because the audible part of the dialog largely exists in the mid frequencies and the audible part of the music largely exists the low and high frequencies, the effect will be very similar to having boosted the level of the music or attenuated the level of the dialog on the track!  Furthermore, if the relative attenuation of the mids in the presentation is similar to or larger than the amount of cut applied to the music, then the music will probably begin to mask the dialog.  What is one of the most common complaints that home listeners have about movies played at home?  It's something like: "the music and FX overpower the dialog, and I can't hear what's being said".  Who woulda thunk it?  Sure, this problem can be reduced by boosting the dialog level a bit, relative to the music, but that's like taking a hammer to screws.  It's much better to treat the root cause of the issue, which is very likely inconsistent tonal balance reproduction between the dub stage and the home.

14 hours ago, Infrasonic said:

Yes, of course. That is how they sound how they sound. Everything that is sound that isn't pure untouched recordings of life, are artificially made. Creations born out of a computer or mixing board. There is nothing "pure" in the music we listen to and especially the movies we watch.

That goes without saying for everything that is produced.

We all do and we all have our own opinion on how it should be done. ;)

Presumably.

Yes, of course. To achieve the best sound, you should EQ to personal taste. ;)

...to personal taste.

 

......to personal taste.

 

:P

Of course soundtracks are largely artificial in origin, but that doesn't mean that it's all meant to sound that way.  As far as movie dialog is concerned the vast majority of time, the intent is for the dialog to be perceived clearly and to sound natural in the context of what's being said and what's happening on the screen.  This makes dialog a good anchor element in the sense that if the dialog reproduction sounds natural, there's a good chance that the rest of the mix (at least in the center channel) will sound as the director intended.

And in so far as what sounds natural to us, personal preferences are actually quite consistent.  The way I perceive the color blue may be different from how you perceive the color blue.  And in terms of overall color preferences, I may like the color blue more than the color green.  But if we both look at the sky, we both agree that the sky is blue, and even though I prefer the color green, I will probably be quite disturbed if the sky looked green instead of blue.

Where opinions will actually differ is with respect to technical matters.  What is the best calibration method to use to ensure that different sound systems exhibit the same subjective tonal balance? What reference should our systems be calibrated to?  I don't believe these questions have been adequately answered yet, particularly for low frequencies.  The best answers we have come from the research done by Floyd Toole and Harman, which shows strong correlation between listener preference and anechoic speaker response, on and off axis, when blindly evaluating music.  I have reason to believe that these findings strongly contradict the use of the X-curve standard for calibration and the X-curve target as the reference.  The standard does not achieve consistency between systems.  The reference is, generally speaking, way off what is preferred by listeners for music.

So as far as how "home mixes should be done", I believe re-EQ is an essential part of the process, and I argue this not as a matter of preference but on objective grounds.  It's practically scientific fact that the tonal balance response of the dub-stage and home environment are worlds apart.  What I find mystifying is that the same mixers who work tirelessly and with great skill to EQ dialog to make it sound its best on the dub-stage would fail to notice tonal balance issues that present during playback on home theater systems.  Perhaps there is a widespread belief that the X-curve calibration standard actually achieves tonal balance parity with small room systems, and that the audible differences arise for entirely different reasons.  Perhaps it's also simply a matter of focus.  The mixer(s) are focused on ensuring the best blend between the different parts of the track.  Maybe the movie industry would benefit from a separate mastering step, performed by a separate engineer whose focus is on the package as a whole, similar to standard practice in the music industry.

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12 hours ago, 3ll3d00d said:

I wouldn't watch the whole film again, don't mind trying some specific scenes though.

That's perfectly fine.  Obviously you had no problem identifying a significant resonance problem in the upper mids.

12 hours ago, 3ll3d00d said:

>> Did you implement the JRiver coefficients that you posted here (what I'm calling "v1")?  Or did you calculate new JRiver coefficients, based the updated "v2" config I posted afterwards?

the v1 ones

>> What playback level (approximately) did you use to evaluate?

-7

>> How are your speakers calibrated?  Do you use Acourate?  And if so, what kind of target curve do you use for the high frequencies?  Or did you use outdoor / anechoic polar response measurements?

current target rises ~5dB from 125Hz down to 25Hz and is basically flat above that, the correction switches at about 900Hz to an anechoic only correction (based on measurements taken outdoor from 0-60 degrees). The speaker itself is maybe 1dB down from 1-16kHz on axis, graphs in http://www.avsforum.com/forum/155-diy-speakers-subs/2188265-attempting-3way-seos10.html#post54724444

 

Thanks for the answers.  Yeah, the "v1" config, in hindsight was definitely suboptimal.  One problem that arises when doing this kind of work is losing one's frame of reference because of adaptation.  I thought it sounded pretty OK when I posted "v1", but when I listened the day after, the upper mid issues were more apparent.  The worst offender was the peaking filter I used to try to sharpen the knee at the transition to the high frequency slope around 2 kHz, but even without that filter, some minor excess over the ~1.2-2k range was still apparent.  My guess is that the "twang" you are hearing is mostly ringing from that peaking filter.

While the "v2" coefficients sounded better to me, I suggest you wait for me to post a "v3" config before doing another trial.  It'll be a little while because I need to do more fine tuning and I plan to wait an extra day afterwards and re-evaluate the next day to avoid any adaptation issues like I encountered with "v1".

As for your speaker response, I have a few comments:

First of all, the pseudo-anechoic measurements show a substantial dip of around -1.5 dB between 5 and 10 kHz.  Even though 1.5 dB doesn't sound like much, such a dip over a full octave will have a pretty big audible impact.  I'm not surprised that you reported that the re-EQ sounded more veiled and distant than you would prefer.  Have you considered EQing to try to lift that dip a bit?  If not, you may want to try using a bit less attenuation on the second HF shelf with my re-EQ.

Second of all, if the speakers were producing flat direct sound in the room, I'd expect to see a slight downward slope in the in-room response over the 500-1500 Hz range, where the horizontal pattern width changes.  However, you indicated that your in-room target is roughly flat from 125-900 Hz.  I can't say what the precise slope should be, but as a rough guess it'd probably be somewhere between -1 to -2 dB/octave.  I would also expect to see a slight in-room response dip around the crossover point at 1200 Hz where the power response reaches a minimum, and maybe something very slight at 300 Hz.  Overall, my guess is that the speakers sound a bit thin without that slope, and any upper-frequency issues in the soundtracks you listen to may be more audible and irritating than on an "average" system.

Lastly, you may want to try a bit more bass in the 125-250 Hz range, at least for music.  My current bass boost shelf is centered around 150 Hz, which is based on my use of the Revel Salon 2 as a model reference.  This sounds very good in the bass with the vast majority of my music and delivers much better punch and chest slam than a boost at the lower frequencies.  However, the trade-off is that many movies and some TV soundtracks will have more bass bloat than if the shelf is lower.

Anyway, my critique of your system is a bit off-topic, being that the point of what I'm doing is to try to achieve sound quality improvements on a majority of home systems.  But, I think it's worthwhile to note these details, given their influence on what I believe you are probably hearing.  While it may not have been your intention, your system response appears to provide more of a compromise between for music and for cinema tracks (lacking re-EQ).  As I stated in my first posts, my re-EQ approach targets a music-optimized system, which I personally regard to be the ideal reference.

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6 hours ago, SME said:

Yes they are wildly different.  But what if dub-stages were optimized for a flat direct sound response (excepting a bass rise under 100-200 Hz or so), consistent with how home systems typically perform, instead of calibrating to the X-curve standard.  Just how many of those remaining differences would be perceptually relevant?  I think that while some perceptual differences would remain, they would be minuscule in comparison.

Scientific evidence strongly suggests that our brains are highly adaptive to different acoustic environments and attempt to deduce the sound of the source independently of the environment.  That doesn't mean that the acoustic environment has no perceptual effect at all, but rather, the influence of the acoustic environment is perceived independently from our perception of the source sound.  The exception to this is that early reflections in small rooms do influence perception of the source, which is why it's important to either: (1) use speaker with good off-axis response in addition to good on-axis response (preferable); or (2) absorb all the early reflections to prevent the ugly off-axis sound from reaching your ears in the first place.

This means that what matters most to perception is the sound that the speaker is making, possibly filtered by the screen material in front.  Recent measurements of anechoic flat speakers in cinemas indicate that they exhibit an in-room frequency response that is much more similar to the Harman curve than anything like the X-curve target.  The response actually looks vaguely similar to what may be measured from a similar speaker in a *much smaller room*.

So while the differences between the acoustics of the two rooms may be substantial, the relevance to perception is likely to be much less than most people believe.  I'd guess that the differences in direct sound response between dub stages and home theaters accounts for 80-90% of the perceived difference in sound between those environments.  In fact, if cinemas were calibrated accurately to match the direct sound response of small room systems, it would probably make far more sense to prepare movie mixes in a small room studio and only use the dub-stage for a final run-through.

 

Good discussion so far.

I'd say that the issue stems from the fact that there is some kind of standard developed for large cinemas, so most of the mixing effort is skewed in that direction. There really is no standard for "home" listening rooms, or even studio mastering rooms. Sure we can come up with some rigid standard of what it should be, but the reality is that it will be all over the place. Once it goes to the consumer for playback all bets are off. You might have someone with a badly setup HTIB 5.1 system, another with playback through a soundbar and a third with a 1% system such as many members here or at AVS. A commercial cinema on the other hand, while it may be quite different from the one across town, will be close to other cinemas in the areas of: Acoustics, room design, shape, gear and playback capabilities comparatively.

How much of the optimization for cinema playback is directly put in the mix, versus compensated for at the playback gear / speaker EQ level, is what I really wonder about. It would be best to use the playback gear to handle that for each room, but if the mixes are truly done in a big cinema room to begin with undoubtedly some of that will get baked in.

EQ is a powerful tool but in my experience once things have been EQ'd multiple times at each step in the process it can begin to muddy the waters and cause a loss of cohesiveness of the mix. It has to be used with care, especially with narrowband filters. That's just my experience. After doing some A/Bing with and without EQ at home I don't use any EQ on my subs other than the low pass filter. With EQ was flatter at the main 2 listening seats but didn't sound better to me. I think it may have something to do with the total bass energy output into the room vs measured at a few pinpoint specific points in the space.

 

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11 hours ago, SME said:

First of all, the pseudo-anechoic measurements show a substantial dip of around -1.5 dB between 5 and 10 kHz.  Even though 1.5 dB doesn't sound like much, such a dip over a full octave will have a pretty big audible impact.  I'm not surprised that you reported that the re-EQ sounded more veiled and distant than you would prefer.  Have you considered EQing to try to lift that dip a bit?  If not, you may want to try using a bit less attenuation on the second HF shelf with my re-EQ.

yes that's what I meant by "an anechoic correction", i.e. the magnitude response correction switches to one based on those quasi anechoic measurements of the speaker. Here's a pic to illustrate

https://imgur.com/a/Meaxg

red is the on axis response, green is the filter based on that response and blue is the result of applying that filter

11 hours ago, SME said:

Second of all, if the speakers were producing flat direct sound in the room, I'd expect to see a slight downward slope in the in-room response over the 500-1500 Hz range, where the horizontal pattern width changes.  However, you indicated that your in-room target is roughly flat from 125-900 Hz.  I can't say what the precise slope should be, but as a rough guess it'd probably be somewhere between -1 to -2 dB/octave.  I would also expect to see a slight in-room response dip around the crossover point at 1200 Hz where the power response reaches a minimum, and maybe something very slight at 300 Hz.  Overall, my guess is that the speakers sound a bit thin without that slope, and any upper-frequency issues in the soundtracks you listen to may be more audible and irritating than on an "average" system.

I don't find that, it sounds quite neutral and well balanced to me. tbh generally speaking I don't find upper frequencies to be an issue with this setup, the system sounds quite smooth to me. My old (commercial) speakers certainly needed shelving down in the same room to avoid harshness and fatigue but these don't at all. 

 

11 hours ago, SME said:

Lastly, you may want to try a bit more bass in the 125-250 Hz range, at least for music.  My current bass boost shelf is centered around 150 Hz, which is based on my use of the Revel Salon 2 as a model reference.  This sounds very good in the bass with the vast majority of my music and delivers much better punch and chest slam than a boost at the lower frequencies.  However, the trade-off is that many movies and some TV soundtracks will have more bass bloat than if the shelf is lower.

I find that sort of curve comes out a bit too fat in my room for both music and films. My room does have produce some bloat over time in that range though atm so that may be the root cause of that one. If so that may change if/when I build my screen wall later in the year.

11 hours ago, SME said:

While it may not have been your intention, your system response appears to provide more of a compromise between for music and for cinema tracks (lacking re-EQ)

It's certainly true that I no longer run different filters for music and films as I find the same setup works well for both. Good job really as I I definitely don't have the time (or inclination/knowledge) to attempt to re-eq tracks myself!  

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@SME, I tried the upper-bass/low-mid cut eq on the center now while checking the BEQ, and it worked well for this movie. BooOOomy voices are gone. I have noticed the problem before, but never thinking that this is a result of the calibration on typical monitoring systems, and that it is possible to do something about it. Could also be due to artistic choice to get fuller voices.

There is no real dsp in the chain on LCR/surround in this system, but the processor allows for simple manual graphic eq. Easy to implement a crude eq on the center, to improve dialog.

The problem with eq on the finished product is that everything gets the same eq, and that may not be the best solution. Doing this for the center only, fixes most of the dialog, while keeping the balance as-is on other sound effects in the other channels. Easy to see the obvious flaw - dialog in L-R and panning will be wrong. Since this will be a compromise regardless how you do it, the center only can be a simple and quick improvement on some movies. 

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2 hours ago, Ricci said:

Good discussion so far.I'd say that the issue stems from the fact that there is some kind of standard developed for large cinemas, so most of the mixing effort is skewed in that direction. There really is no standard for "home" listening rooms, or even studio mastering rooms. Sure we can come up with some rigid standard of what it should be, but the reality is that it will be all over the place. Once it goes to the consumer for playback all bets are off. You might have someone with a badly setup HTIB 5.1 system, another with playback through a soundbar and a third with a 1% system such as many members here or at AVS. A commercial cinema on the other hand, while it may be quite different from the one across town, will be close to other cinemas in the areas of: Acoustics, room design, shape, gear and playback capabilities comparatively.

There is no formal standard for homes or home mastering rooms.  However, a very good informal reference is a system using speakers that have a flat anechoic frequency response and consistent off-axis frequency response, and are placed at least a few feet away from walls.  Research by Floyd Toole and Harman of speaker prefer by blinded music listeners suggests that speakers with this kind of speaker are preferred from among many others tested.  The reference is not perfect and does not precisely define what bass response should look like after accounting for the influence of the room.  However for mid and high frequencies, where evidence strongly suggests the speaker sound dominates perception, I believe this reference is consistent and reliable.

Cinemas do rely on formal standards, but unfortunately they are not based on measurement of perceptually relevant quantities.  The informal reference I describe above is defined with respect to speaker anechoic response or what we might call in-room direct sound response.  The X-curve standard on the other hand relies on measurement of continuous pink noise and does not adequately distinguish between sound produced by the speaker and sound reflected back by the room at later moments.  As stated before, perception of mid and high frequencies depends primarily on the sound produced by the speaker, but the reflected sound field depends substantially on other variables such as speaker radiation pattern vs. frequency, room size, listener distance, and properties of the room boundaries.  This means that the same speaker, calibrated to X-curve standards in different rooms, will be EQed differently in each room to satisfy the standard, which implies that the sound will also differ between those rooms, despite the use of the same speaker and the same "calibration".  Furthermore the power-averaged pink noise response of a flat speaker when measured in a typical cinema room will have no resemblance at all to the X- curve target.  Forcing the measured response to conform to the X-curve target typically requires attenuating both high and low frequencies, leading to a speaker sound that will tend to sound heavy in the mid-range when used to play typical music content.

4 hours ago, Ricci said:

How much of the optimization for cinema playback is directly put in the mix, versus compensated for at the playback gear / speaker EQ level, is what I really wonder about. It would be best to use the playback gear to handle that for each room, but if the mixes are truly done in a big cinema room to begin with undoubtedly some of that will get baked in.

As I stated above, a flat speaker measured in a cinema exhibits a power-averaged pink noise response that looks totally different from the X-curve.  So not only is the calibration failing to compensate for perceptually relevant differences between rooms (which would be expected to only appreciably affect bass frequencies anyway), but the calibration is causing the sound in cinemas to deviate substantially from that of other audio systems.  I would guess that X-curve calibrated cinemas also sound worlds apart from PA/music systems used in similarly large rooms.  Compensation for this abnormal response caused by X-curve calibration is almost certainly baked into the mixes, even if not intentionally.

9 hours ago, Ricci said:

EQ is a powerful tool but in my experience once things have been EQ'd multiple times at each step in the process it can begin to muddy the waters and cause a loss of cohesiveness of the mix. It has to be used with care, especially with narrowband filters. That's just my experience. After doing some A/Bing with and without EQ at home I don't use any EQ on my subs other than the low pass filter. With EQ was flatter at the main 2 listening seats but didn't sound better to me. I think it may have something to do with the total bass energy output into the room vs measured at a few pinpoint specific points in the space.

I agree with your general assessment of EQ here, and I agree that it's usually best to limit its use to broad adjustments.  Despite knowing better, I made this mistake in the "v1" config I published for "Wonder Woman".  The narrow-band positive-gain peaking filter near 2 kHz, intended to sharpen the knee at the transition point of the X-curve target shape definitely caused more harm than good.  In hindsight, that filter would only have been beneficial if: the dub-stage used had been calibrated with a similarly sharp knee, and the mixers introduced a negative-gain peaking filter to counter-act the resulting resonance.  My guess is that experienced system calibrators purposely avoid sharpening the knee there because of the resonance it causes.

It's interesting to hear that you avoid using EQ on your subs.  As you know, I've taken kind of the opposite, using aggressive EQ and specialized software to smooth response at multiple measurement locations.  I am able to obtain very smooth frequency response with at those locations, but I cannot make the response precisely flat at each of those locations.  The absolute frequency response varies with location a lot more for mid bass than for deep bass frequencies, and the mid bass is quite a bit hotter closer to the center seat.

All this is well and good, but it lead to another question.  How should I calibrate my response in a broad sense?  Should I calibrate for a flat response at the seat I most often sit in?  Should I calibrate so that the response at every seat is either flat or tilted up toward the low end?  Or perhaps I should calibrate so that the spatially averaged response across all the seats on the sofa is flat?

I decided to try to answer the question by listening and adjusting a low shelf to adjust the balance of deep bass to mid bass.  I purposely sought out passages of music that had significant deep bass content.  I have some electronic music with leads whose fundamentals that play well down into the 30s Hz.  What I found was quite remarkable.  First of all, there was a fairly narrow range of values for which the shelf sounded good.  Any more than +/- 0.5 dB or so from ideal, and the bass quality was obviously inferior.  Second of all, the perceived quality of the bass was actually fairly consistent from seat-to-seat.  It does seem a bit stronger in the center seat, but the balance is mostly the same.  This is the part that is most fascinating because the variation in mid bass response between seats is quite a bit more than +/- 0.5 dB.  Third, the best bass heard in any seat was with a flat spatially averaged bass response.

To emphasize just how unintuitive this results are, I'll note that the measured response in my center seat as the mid-bass maybe 3 dB higher than the deep bass.  Yet, if I use the low shelf to add +1 dB more to the deep bass while sitting in the center seat,, the bass falls apart.  The deep bass lead turns to mud, and the kick becomes boomy and loses most of its tactile punch.

I wish I could conclude from this experiment that "the correct way to calibrate the sub bass" is to make the spatially averaged response flat, but it's not that simple.  The shape of the spatial average depends on which measurements I include in the average.  If I included measurements at locations beyond the ends of my sofa, I would end up boosting the mid-bass even more to make the spatial average flat, and this would probably not sound as good.  Furthermore, the bass definitely sounds inferior in many areas of the room outside of the seating area.  Unlike the sound above 250 Hz or so which is subjectively uniform throughout the room (except in the front corners of the rooms at extreme angles to the horns), the bass definitely sounds different in different parts of the room.

All of this begs for more investigation because it would be very helpful to have a better understanding of bass perception, especially for those situations in which there is not enough time or skill to optimize bass response by ear.

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9 hours ago, 3ll3d00d said:

yes that's what I meant by "an anechoic correction", i.e. the magnitude response correction switches to one based on those quasi anechoic measurements of the speaker. Here's a pic to illustrate

https://imgur.com/a/Meaxg
red is the on axis response, green is the filter based on that response and blue is the result of applying that filter

Thanks for the clarification!

As a slight alternative to the approach you took, you may want to try doing a +/- 30 degree (listening window) spatial average of the anechoic measurements EQing that to be flat instead.  It's hard for me to tell by looking at your plots how much the high frequency response shape varies with angle.  With my SEOS-15, I see up to 1 dB of variation in the response shapes, up to 10 kHz or so.  (The variation is a bit higher above 10 kHz.)  Perhaps the SEOS-10 is better behaved in that respect.

I preferred the sound from flattening the listening window average response instead of the on-axis response.  I also noticed that Harman appears to calibrate their active speakers for a flat listening window response instead of flat on-axis response.

10 hours ago, 3ll3d00d said:
21 hours ago, SME said:

Second of all, if the speakers were producing flat direct sound in the room, I'd expect to see a slight downward slope in the in-room response over the 500-1500 Hz range, where the horizontal pattern width changes.  [...]

I don't find that, it sounds quite neutral and well balanced to me. tbh generally speaking I don't find upper frequencies to be an issue with this setup, the system sounds quite smooth to me. My old (commercial) speakers certainly needed shelving down in the same room to avoid harshness and fatigue but these don't at all.

21 hours ago, SME said:

Lastly, you may want to try a bit more bass in the 125-250 Hz range, at least for music.  [...]

I find that sort of curve comes out a bit too fat in my room for both music and films. My room does have produce some bloat over time in that range though atm so that may be the root cause of that one. If so that may change if/when I build my screen wall later in the year.

One crucial detail I neglected to mention or take into account here is that I generally avoid evaluating in-room response without taking averages of measurements in multiple locations.

In the case of the 500-900 Hz response, if you took measurements across a +/- 30 degree listening window and weighted them for relative distance before averaging, you might see more  slope there after all.  I just took a look at my own crop of measurements and noticed that in areas of changing directivity, both on-axis and MLP measurements stay somewhat flatter than the listening window average measurements.

As for the bass in the 125-250 Hz range, your ears are definitely the final arbiter on any calibration decision.  It's possible that the bloat you are hearing is caused by just one bad resonance.  Such resonances can be difficult or impossible to see in a measurement at a single location because they are hard to distinguish from peaks and dips caused by interference.  However, if you take measurements in multiple locations and spatially average them, problematic resonances are more likely to stand out.  If you can suppress the bad resonance, you may be able to boost the output in that frequency range a lot more without causing bloat.  If it is a room problem, then the screen wall may not fix the problem but it probably can't hurt.

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8 hours ago, Kvalsvoll said:

@SME, I tried the upper-bass/low-mid cut eq on the center now while checking the BEQ, and it worked well for this movie. BooOOomy voices are gone. I have noticed the problem before, but never thinking that this is a result of the calibration on typical monitoring systems, and that it is possible to do something about it. Could also be due to artistic choice to get fuller voices.

I'm not familiar with that track, so I'll have to take your word for it that it is likely a cinema track with excess low frequencies.  You didn't say anything about trying to reduce the high frequencies, which I would probably try doing as well.  However you may have found the low frequency excess to be much more offensive, and I find this is often the case with more recent mixes where the highs are often not pushed as hard as they could be.

You mention that fuller sounding voices may be an artistic choice.  Almost all dialog is heavily processed with EQ to compensate for a variety of problems that arise with trying to record it, so in some sense, *all the dialog you hear is manipulated to fulfill artistic goals*.  However, the goal is almost always to present the dialog with clarity in a way that sounds natural for what is being depicted on the screen.  In most cases, the dialog should not sound so overly full that intelligibility is harmed.

If you pay close attention, you will notice that in many movies, the tonal balance of the dialog shifts depending on the scene.  That's because the sound of dialog does change a bit under different real-life circumstances.  For example, when a listener (or a mic) gets very close to a person who is speaking, the low frequency part of the sound is boosted because of boundary gain effect from the speaker's body.  Some mixers will boost the low frequencies in camera "close ups" to make it sound more realistic.  Low frequencies also tend to be boosted by boundary gain in very close quarters like inside of cars or for actors/actresses whose heads are very close to a wall or corner.  On the flip-side you'll often hear the "radio voice effect" used when the dialog is being spoken through a radio, phone or TV set, to simulate the limited low frequency output of the device.  Often the high frequencies are rolled off as well, and some distortion may be added for a lo-fi sound or for "crackling" effects.

The point here is that when it comes to dialog, artistic intent is usually quite obvious based on the context, even when voices are purposely distorted with EQ as may often be done for robots, villains, or mythical creatures.  It the dialog sounds unnaturally full to you, it probably is, and it is not consistent with director intent, meaning it's either a fault in your system reproduction or it's a mix/master translation problem.

8 hours ago, Kvalsvoll said:

There is no real dsp in the chain on LCR/surround in this system, but the processor allows for simple manual graphic eq. Easy to implement a crude eq on the center, to improve dialog.

The problem with eq on the finished product is that everything gets the same eq, and that may not be the best solution. Doing this for the center only, fixes most of the dialog, while keeping the balance as-is on other sound effects in the other channels. Easy to see the obvious flaw - dialog in L-R and panning will be wrong. Since this will be a compromise regardless how you do it, the center only can be a simple and quick improvement on some movies.

Does the processor allow GEQ to be applied to the other channels too?

I agree that applying the same EQ to all channels may not be the *best* solution, but it is probably much better than applying EQ only to the center.  That is, unless your center channel response is off, the problem of low frequency excess is most likely caused by a soundtrack being mixed in an X-curve calibrated environment or possibly a home-mix room that calibrates to a "flat in-room response" (as is often the case with TV programming these days).  In other words, if the center channel content is hot in the low frequencies, then the content in the other channels probably will be to.

Theoretically, the X-curve calibration process can skew the response of each channel in a given room in different ways.  The left and right channels may interact with the room a bit different than the center.  The situation with the surrounds is even messier.  Often surrounds are calibrated with a target slope that starts at 4 kHz instead of 2 kHz, and IIRC recent real-world measurements suggest that surround calibrations are a lot more likely to be off target than the screen channels, even in dub-stages.

Thankfully, tonal balance is far less important for surrounds than for the other channels, especially the center channel because our hearing is most sensitive to flaws in dialog reproduction.  So far, I've been applying the same EQ to all channels, and I'm pretty happy with the results of that approach.  Though it may still sound better to attenuate the sound of the surrounds less in the 2-4k range.  I'll worry about that some other day when I have the tools I need to do this re-EQ thing much more quickly than I can now.

BTW, here's a random weird factoid.  I have heard that the speakers that get installed on the ceiling in most Atmos cinemas actually have the 4kHz X-curve target slope baked into the passive crossover.  That to me is an explicit acknowledgement by the industry that the high frequency slope in the X-curve serves no acoustic purpose and is just a peculiar feature of cinema audio that continues to survive because of a legacy standard that continues to persist.  Too bad the industry still seems to be ignorant about the low frequency side-effects of the X-curve process.  Perhaps the Atmos speaker manufacturers should be baking in something like a -4 dB @ 250 Hz low-shelf as well?

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Tonight I put in "Toy Story 2" along with a generic X-curve correction.  These older Pixar mixes were prepared on dubbing stages at Skywalker sounds and are extremely tight mixes.  However, they also obviously target an X-curve calibrated cinema rather than a neutral system.  The early "Toy Story" mixes are bright as hell, and I find them intolerable to listen to without correction at more than like "-9" or so. 

My generic X-curve correction provided -4 dB @ 250 Hz with Q=0.625, a -2 dB/octave slope from 2-10 kHz, and a bit more top-end roll-off.  With this correction in place, the brightness was well tamed and the low frequencies sounded very good.  The low-mids and bass in the dialog sounded very clear and natural, and the big bass effects were both powerful and punchy/tactile.

However, there was one lingering problem with this configuration: There was some obvious resonance at 2 kHz, and this was still there even without the 2 kHz knee that I tried using before.  Throughout the film, I trialed a variety of other high frequency configurations which shifted the resonance to various places ... 3 kHz, 4 kHz, 5 kHz, 1.5 kHz.  These are approximate guesses based on my memory of sussing out problems with my own system configuration back before I'd sufficiently refined my systematic approach to get it right, once and for all.  All of these resonances sound a bit irritating (with severity that depends substantially on the bandwidth and gain), but the nature of that irritation is different depending on the frequency.  Resonances at some frequencies are a lot more annoying than others.

After a lot of fussing and fighting, I finally arrived at a sound I could "live with", which had some mild resonance in the 7-10k range (which delivers a kind of prickly ear sensation) and some mild lingering resonance around 2k.  The last iteration also seemed a tad muted in the upper mids, which if corrected might neutralize the prickly resonance.  I don't know whether to publish the config I ended up with because I know I can improve on it a lot.  However, my current process for doing these is very slow, and it gets much harder when I get to the part where things need to be fine tuned.  Keep in mind that 0.25 dB is quite a significant change when doing this work.  A "subtle" change is closer to 0.1 dB.  To me, the tamed lows and highs makes the track much more comfortable and enjoyable to listen to, but the lingering resonances make it sound more flawed, if that makes sense.

I'm thinking I am really going to need a curve-editing app with live-updates to really do these well.  My hope is that with practice and the right app that I could do a high quality re-EQ / meta-data remaster in the time it takes to play through the movie.

On one more note, I encounter problems around 2 kHz more often than anywhere else when applying these corrections.  I also notice problems around 2 kHz more often than anywhere else when listening at cinemas.  I think the problem is due to the abrupt change in  the X-curve slope at 2k.  Subjective frequency response has more to do with relative differences than absolute differences.  The trend changes abruptly at 2 kHz, and even if one avoids "sharpening the knee" there, I suspect that the subjective response on dub-stages and cinemas is a lot less consistent at 2 kHz than at surrounding frequencies because of the abrupt change.  It's kind of a question of "how sharp should the knee be?"  While 2 kHz is certainly not the worst place to have a resonance (I'll take it over pretty much anything between 2.5-4.5k), it still contributes a lot of loudness and "roughness" (for lack of a better adjective) to the sound.  Even a mild (i.e. 0.25 dB) peak around there is reason enough for me to want to back the master volume down a click or two, so it would not surprise me if problems like these motivate cinemas to do the same.

 

Edited by SME
fix typos

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