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maxmercy

The Low Frequency Content Thread (films, games, music, etc)

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Looks like it's roll-ed off a bit below 30 Hz.  Could benefit from BEQ maybe?  I know one thing I really wished for in the Interstellar track was those bottom notes on the organ, down to 16 Hz.  This track looks like it has at least some life down there, but could there be more?

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Is the streamed version a multichannel track with LFE?  Or is it only 2 channels?  If it's 2 channels, it's possible they omitted the LFE channel on the mix down.  Going by memory, I think the LFE channel often gets more 30 Hz hump than the screen channels.

This looks like yet another track with BEQ potential, but that 8 Hz peak looks intimidating, kinda like the one in TIH that overloads my sub amp.  :P

 

Edit: On second thought, I don't see an obvious 30 Hz hump.  Though, the BD version still has a lot more output there, relative to the higher frequencies.  It may still be a difference of LFE vs. no LFE.

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9 hours ago, MrEdge said:

it was a 5.1 track.

Now *that's* weird!  It looks like the streaming version has hotter bass overall as well.  Hotter bass and smoother bottom end roll-off.

Does the disc by chance have a separate 5.1 track on it?  Maybe the 5.1 track on the disc matches the streaming track.  Maybe it is a mix-down from the cinema track vs. home mix for the 7.1.  Apart from bass, did you notice any significant loudness differences between the 7.1 BD vs. 5.1 streaming tracks?

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13 minutes ago, MrEdge said:

Yes it does ill have to check it out. the streaming track is louder even though it graphs the same except the boost in the areas shown, the track is louder even in the dialog areas. the boosted area adds allot and it's insane and goes through your body when listened to compared to the BD:o.

I am sure i am not the only one who have noticed this but in movies where the BD have a DTS-MA track but the UHD of the same movie has Atmos track even though they graph exactly the same the Atmos track is allot louder. i am sure it's in the meta data. a perfect example of this is Alien: Covenant which the Dolby Atmos track is louder by maybe 6db or so when i tried to match it with a spl meter., but it is a common thing Ive been seeing for a while.

Very Interesting.  While nothing here constitutes definite proof, it does seem reasonable to me that the streaming version is a cinema track mix-down; whereas, the BD version is a re-EQed dedicated home mix.  As I've argued before, cinema tracks need quite a bit more low frequency oomph for good impact in an X-curve calibrated cinema.  That's because X-curve calibration undoes the natural in-room bass rise exhibited by an anechoic flat speaker due to boundary gain and reverb build-up.

Of course a lot of people at home also have systems with less bass output, either because they calibrate to a flat curve (e.g. Audyssey) or because their speakers lack BSC or because they have boundary interference problems.  Nevertheless, it appears that recent BD releases with home mixes done at Skywalker Sound Studios have re-EQ to better match systems that perform optimally for music playback.

In terms of the graphs, the streaming version looks 5-7 dB hotter through much of the sub region.  However, the gap may be much smaller after compensating for loudness differences in the mids and highs.  In that case, it may be more accurate to say that the BD version is hotter than the streaming version in the 15-35 Hz region.  Certainly the shift of balance toward deep bass could reduce the apparent level of mid-bass, even if the SPL is similar after compensating for loudness difference in the mids and highs.

There's a good chance I'll buy the BD version of this film.  I may be tempted to try out the streaming version to satisfy my curiosity.  I could give my opinion as to whether the streaming version sounds like it is influenced by cinema EQ, for what that's worth.

That UHD Atmos tracks often sound louder than BD DTS-MA is a curiosity.  Almost all DTS-MA tracks have "0" dialnorm offset, and I don't believe any format supports positive offsets.  It's possible that a lot of Atmos "home" tracks are just mixed hotter than the cinema versions, from which the DTS-MA may be derived from.

Unfortunately, there are still no formal standards for home mixing and apparently no consistency between studios.  For example, I believe (based purely on my subjective evaluation) that Skywalker Sound Studios applies re-EQ to home mixes, whereas most other studios don't.  Skywalker Sound also appears to have a dedicated mix room and to use a calibration/mix level that's comparable (in terms of room size differences) to cinemas, i.e. 80-82 dBC @ 500-2kHz.  Such mixes are likely to sound quieter, in addition to benefiting from more headroom and cleaner micro-dynamics than cinema mixes.

OTOH, it appears that some studios monitor home mixes with calibration as low as (or maybe even lower than) 75 dBC and may still be monitoring near-field in a large room.  Such tracks are likely to sound even hotter than cinema tracks and have more potential for clipping and other problems.  Also under those conditions, the need for re-EQ is likely to be much less obvious for a number of reasons: (1) tonal imbalances are much less obvious and offensive at lower levels especially excess brightness; (2) lack of boundaries reduces low frequency boundary gain that boosts the bass of flat speakers / mid-field monitors in "small" rooms; and (3) per Floyd Toole, rooms with early reflections are more revealing of tonal balance flaws in a speaker, and I'd argue that this extends to soundtracks as well.

From my knowledge, near-field monitoring in a large room is probably the worst environment to monitor a home mix in.  Simply monitoring the mix on the dub-stage system, albeit with a Harman-like curve instead of the stupid X-curve, is likely to offer better translation than "near-field".  Somehow I need to get the industry people over to my house to listen to and compare mixes.  :)

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Holy humped filter Batman!

It looks like they used PEQs instead of shelves to attenuate the low-end, given the sharp rise below 3 Hz.

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Hi - started to watch the old Mel Gibson movie We were soldiers. Saw it many years ago on dvd with a dts sound track. Remember the napalm scenes as good house shakers. Bought same movie as blu ray with dts hd master track and ... what a disappointment ! Found in this thread someone else saying that bluray is filtered and dvd is not. 

What I cannot get into my head is why ? Why does anyone wants to ruin and make a sountrack boring. Is it to favour the ones without subwoofers - the ones that only has tv ? 

Glad that I bought this very cheap - but there is no way of telling before you try it. 

I ended up watching the dvd edition - the bluray was just too boring !

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6 hours ago, Thomasdk1405 said:

Hi - started to watch the old Mel Gibson movie We were soldiers. Saw it many years ago on dvd with a dts sound track. Remember the napalm scenes as good house shakers. Bought same movie as blu ray with dts hd master track and ... what a disappointment ! Found in this thread someone else saying that bluray is filtered and dvd is not. 

What I cannot get into my head is why ? Why does anyone wants to ruin and make a sountrack boring. Is it to favour the ones without subwoofers - the ones that only has tv ? 

Glad that I bought this very cheap - but there is no way of telling before you try it. 

I ended up watching the dvd edition - the bluray was just too boring !

Obviously, they remixed the track for the BD release.  There are many good reasons to do remixes, but unfortunately the quality can vary a lot.

As for filters, chances are that the mixers had no idea what they were cutting out.  Often the systems used for these remixes aren't really up to the task.  I've seen evidence that tiny near-field monitors and a single compact near-field sub, used in a huge room.  Such a sub is likely to struggle to keep up even with the content above 30 Hz and at the lower monitoring levels commonly used.

There are many possible reasons the filters get applied.  First, many mixers assume the content below a certain point does not contribute to the mix and apply the filter as a matter of habit.  Most cinema systems don't extend below 30 Hz either, so this shouldn't be a surprise.

Second, mixers may be applying filters to protect their own equipment or prevent it from distorting.  This is very unfortunate because I'd argue that the mixers ought to be applying such filters to their monitor output and not to the soundtrack itself.  On the other hand, some mixers worry that if they can't hear what's going on "down there", then something they don't want to have on the track may slip through.  I would argue that this happens anyway because of a combination of issues: poor quality monitors (which is most of them), poor quality listening space (near-field monitoring in a large room is a very poor listening environment for hearing soundtrack details), etc.

Third, mixers may be applying filters in order to make the soundtrack louder.  I'd argue that this is something that shouldn't happen for a home remix but probably does.  While home remixes should be monitored at a lower level, consistent with changes in listening distance, room size, and other factors, they are often monitored at even lower levels than that.  The assumption is that home listeners will listen even more quietly than a "room appropriate" reference level, so the mixers want to boost low level details to ensure they aren't lost.  I don't really have a problem with that, but it goes very wrong when mixers start boosting the level of loud content too, in order to "increase impact" or "satisfy director's intent".  The fact is, home listeners don't usually set their volume to a number but do so by ear based on loudness, so boosting loud content will only make home listeners turn down the content more, especially if they hear clipping and distortion that often gets introduced in such a process.

I suspect that earlier home mixes including many BD re-releases suffered more from quality problems than more recent home mixes.  Dedicated rooms designed to mimic home theaters and using better quality monitors (such as the new JBL M2/708 series) are becoming more common.  However, filtering in general is still wide-spread and is more the norm than the exception, as can be seen by following this thread.  We can only hope that, in time, more dedicated rooms are built and equipped with more capable sub systems.  I can understand the concerns about equip a full size dub-stage with subs that extend into the single digits, but in a dedicated home theater mix room, this kind of setup should be much more practical.  We'll see.

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For We Were Soldiers (and Master and Commander to boot) appear to have been filtered for BD release, if the original theatrical track is filtered then there's not much a home mix can do about it I would imagine.  

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6 hours ago, minnjd said:

For We Were Soldiers (and Master and Commander to boot) appear to have been filtered for BD release, if the original theatrical track is filtered then there's not much a home mix can do about it I would imagine.  

That's not necessarily true, at least if the mixers are recent enough.  From what I understand, "mixes" these days are actually implemented in meta-data rather than done literally.  That's to say that a "mix" now-an-days consists of all the original tracks and objects along with instructions regarding how they should be combined.  When an engineer hits "play" or instructs the system to export content for master, everything gets mixed in the DAW on-the-fly.

If that's the case, then the filter(s) may just be meta-data regarding how to process a certain group of sounds or perhaps specific destination channels.  Those filters could in principle be changed with just a few adjustments in the software.  Of course, adjusting the filters is likely to have other knock-on effects such as a suddenly increasing headroom demand in parts that could lead to more aggressive activation of compressors, limiters, and/or more propensity for clipping.

Of course, if it's a high headroom home mix with re-EQ, then there might be extra headroom for a more relaxed filter ... or not.  If a mixer can adjust EQ levels for dialog separate from FX, then he/she might pull back the bass a bit in the dialog while leaving most of the sub effects hotter.  Why not?  Everyone likes more bass, right?  Then again @maxmercy's BEQ work suggests there's already plenty of spare digital headroom in most tracks to not use filters.

Incidentally, I have heard that there is some kind of unofficial limit for bass-managed output that the industry is supposed to adhere to, something like 120 dB total @ reference.  (?)  I think cinemas are told to spec their subs to be able to reach that level of output.  However as evidenced by measurements here, not every soundtrack actually adheres to that limit.

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I think you're right on how sound is done.  It's all ProTools these days, and it stores everything including the mixing desk automation.

However I question just how much effort these studios put into their home mixes.  Do they actually take the time to remix the entire film for home viewing or do they just slap some EQ and dynamics processing on the theatrical track and call it a day?  Take a look at The Force Awakens; there is no good reason for a -3dB limiter other than the fact that they were looking for a cheap way of reducing the dynamic range and that was the solution.  That's why I think the amount of bass filtering in home releases is almost always the same (or worse) than the theatrical track, rarely is it better.

 

Of course it would be a lot easier to figure out if we could just get a peek at a PvA graph for an actual theatrical track.  The Blu-Ray of The Game doesn't count since the theatrical and home mixes on that release were done so far apart (and with completely different mixing setups I would imagine).

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You make a good point and are probably right that at least some home mixes are done with very minimal effort.  We have no idea why the -3 dB limiter was put on the TFA track, and purposeful dynamics reduction is only one possibility of many.  I do believe the TFA track was re-EQed, and I actually think it is very nice sounding as far as EQ balance is concerned.  Of course, that doesn't necessarily mean that they devoted a lot of time to perfecting it.  Maybe Skywalker Sound Studios offers a kind of standard re-EQ filter-set that they recommend to mixers as a starting point that generally works well for content mixed in their cinema track facilities.

Seeing PvAs of cinema vs. home mixed versions of a track would certainly be insightful.  Even better would be to hear from the mixers themselves, but unfortunately, they don't frequent forums much.  And when they do, they often have to confront a lot of negative sentiment about their practices and about the quality of the mixes.  I can't blame them for not wanting to visit when they face so much vitriol, but I also don't believe it's one-sided either.  In some exchanges (not naming any names here) I have noticed a know-it-all attitude and an unwillingness to  consider alternative viewpoints.  I've seen insistence that home systems are inherently inferior to larger room systems or that small rooms can't adequately reproduce the lowest bass frequencies.  (!)

Then there's the stubborn insistence that mixing in the near-field somehow approximates a home environment better than a dub-stage, even though the data I've seen suggests more similarity between a home theater and dub-stage than between near-field and either environment, particularly if the dub-stage is calibrated to a more neutral target than the X-curve.  By itself, the reliance on the X-curve standard is a serious embarrassment to the industry, a problem I don't blame on mixers because they have a job to do which is not calibrating the systems or developing the standards.  Nevertheless, it is for precisely that reason that the insistence of "knowing what's best" for production of home content deserves serious criticism.

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Justice League did the Avengers filter....too bad.  Haven't really gotten into the DC expanded universe.

MrEdge, any idea where in the film that ULF peak is?  It is significant....

JSS

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