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Analyzing Waveforms of Heavy Hitting Movies

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Bossobass Dave    241

SME,

 

I used to use AVR processing/bass mgmt to study the tracks, but there are so many ways that AVRs handle the digital data with various xover and LFE cutoff points and slopes that I only look at the digital data now, no filters, only summation with proper channel levels.  While I know that isn't what a subwoofer amplifier sees, it is the most apples-apples way I could think of doing it.

 

 

JSS 

 

 

Agreed.

 

The exercise is to see what's encoded on the soundtrack.

 

Signal chain disparities are infinite and have nothing to do with what source an amplifier can reproduce. We already have a good idea how systems perform with internal signal manipulation using current test methods. For example:

 

9c6Htew.png

 

A mic'd version of this example, using soundtrack source, would reveal a huge distortion in presentation. That is more a matter of the amplifier/alignment/price/performance/driver(s) relationship than what the amplifier alone might be able to present in a waveform comparison.

 

The better comparison is what happens at the listening position, which includes the room, the system and the signal chain and the typically ham fisted post smoothing EQ.

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Shredhead    131

I'm trying to keep this thread consistent with the sub out from 1 piece of equipment with no alterations to the signal for a baseline to compare film soundtracks.  Max has the best idea with digitally analyzing the soundtrack to purely see a comparison between soundtracks.  This is the next closest step to that as long as I keep it consistent with the output of this player.  Of course if you shape the signal it's going to change the waveform, that was never something that I overlooked SME, it's just not something that I'm getting into in this thread. 

 

I'll get into that when I start to publish the amp testing data that I've gathered over the past year but it will have to be in the bass gear side of things and I'll need enough time to spare to dedicate to the effort.  In my experience when analyzing the waveform of movie content most everything in the signal chain has an affect on it.  Even just the slew rate of the amp itself distorts what the waveform of the source should be.  It's an interesting topic for sure but not one for this side of the forum. 

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SME    211

Shred,

 

I used to use AVR processing/bass mgmt to study the tracks, but there are so many ways that AVRs handle the digital data with various xover and LFE cutoff points and slopes that I only look at the digital data now, no filters, only summation with proper channel levels.  While I know that isn't what a subwoofer amplifier sees, it is the most apples-apples way I could think of doing it.

 

That makes perfect sense if the objective is to analyze the content directly rather than assess what kind of signal a sub  amp is being asked to reproduce.

 

I'm trying to keep this thread consistent with the sub out from 1 piece of equipment with no alterations to the signal for a baseline to compare film soundtracks.  Max has the best idea with digitally analyzing the soundtrack to purely see a comparison between soundtracks.  This is the next closest step to that as long as I keep it consistent with the output of this player.  Of course if you shape the signal it's going to change the waveform, that was never something that I overlooked SME, it's just not something that I'm getting into in this thread.

 

After re-reading this thread from the beginning, I totally get what you and JSS are saying here.  I think this is the right approach for comparing content between films.  However, in an earlier post, you wrote:

 

Stay tuned and I'll show some real world movie content shots of transient waveforms and their time duration zoomed in on to see if that helps pick a burst frequency that most closely matches the stresses that some of the coolest bass hits in movies inflict.  

 

And you followed this post with data for "Bourne Legacy" along with comments about how long an amp capacitor reservoir would need to be able to sustain output in order to reproduce the (mostly 40ish Hz) transient accurately.  That was the context for my comments.

 

If you want to know what various bass scenes demand from your amp, then you need to look at what signal is being fed to the amp or you need to calculate it based on knowledge and/or measurements of your signal chain response up to the amp.  If I had an easy way to get digital data off my discs (i.e., I ran Windows on a computer a Blu-ray drive), I'd consider doing some simulation examples.  If someone wants to send me some source data in a usable format along with a good "representative signal shaping" curve, I could do the required calculation.  It might be good to throw in a representative amp roll-off curve too, because presumably the roll-off will be in the input stage.  In other words, you don't expect heavy energy at 1 Hz to demand much from most amps just because most amps are heavily rolled-off at that point.

 

We can also take this discussion to another thread.

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maxmercy    331

Another thread would be ideal.

 

The signals fed to the SW out can be higher than what is encoded on the disc, as I used to measure through the sub out of an AVR with all speakers set to small and crossed at 250Hz.  There were several films that had >128dB content, clipping the soundcard input setup to to record a max 128dB (Immortals, TF3, and TDKR come to mind).  Replicating that processing in the digital world had very similar results, but still leaves out the DAC step.  Those lowpasses, esp if applied to clipped content in the LFE channel, can make for some signals hotter than expected.  Usually just by a dB or two, but once summed, they make a difference.  

 

That's why I like WCS scenarios to test with, more for the signal chain than anything else, as I have found some AVRs and processors quite lacking in the headroom department when it comes to channel summation.

 

JSS 

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Shredhead    131

Hey SME, fuck off.  I said I want to keep the waveforms in this thread consistent with the output of the player as a database of content to refer to.  I'm allowed to do that fuckface. 

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Ricci    652

Hey SME, fuck off.  I said I want to keep the waveforms in this thread consistent with the output of the player as a database of content to refer to.  I'm allowed to do that fuckface. 

 

So what you're saying is you don't like him or his face...?

 

This is blown out of proportion... I wasn't suggesting change your thread or that it be a long term thing and I don't believe SME was either. To the best of my knowledge I've never seen anyone post an SL or waveform capture comparison of what is on the disc vs the modified signal going into the amp with a capable boosted sealed system. I think that would be really cool information to see posted by someone. Just a couple of screen caps from a heavy hitter movie posted in a different thread, one time, to show what the amps are really being asked to do. I like the format you have been using in this thread and you have access to good equipment and the right sort of system to do it that's why it was suggested.  

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3ll3d00d    72

This is blown out of proportion... I wasn't suggesting change your thread or that it be a long term thing and I don't believe SME was either. To the best of my knowledge I've never seen anyone post an SL or waveform capture comparison of what is on the disc vs the modified signal going into the amp with a capable boosted sealed system. I think that would be really cool information to see posted by someone. Just a couple of screen caps from a heavy hitter movie posted in a different thread, one time, to show what the amps are really being asked to do. I like the format you have been using in this thread and you have access to good equipment and the right sort of system to do it that's why it was suggested.  

I posted some examples in http://data-bass.ipbhost.com/index.php?/topic/304-edge-of-tomorrow-discussion-poll-closed/?p=9425

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Shredhead    131

Yeah Josh, like I said I can show that stuff when I post amp data on the other side of the thread.  And no, I don't like SME.  He can go find someone else to fuck with.  If you think that's not what he's doing then please go find me some of his posts to me that don't end up scrutinizing something I've said/done and derailing the thread while he contributes his usual nothing in return.

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Shredhead    131

220px-Terminator_Genisys.JPG


Terminator Genisys -Atmos track defaulted to 7.1 Dolby TrueHD


Biggest hits seem soft limited to 1.3Vpk which is -6.91dBV from a WCS


Zooming in on waveform for the largest peaks doesn't indicate the use of square waves for the soundtrack.


 


00:02:05


eb811c4879c5bfadbff1143cbe8ba206.png


bf8bbb71d26c5790c9bdcd6a5d9a4fcd.png


 


 


01:28:32


748def2b49d9e16ddfcab332e3227e2c.png


65676aea950620970ffc54aa12319c48.png


 


 


01:45:17


f82c8ffff6272f835b9016f1a18b72c8.png


235f0c4a63b36817fff752f52591e91f.png


 


 


01:47:40


486fa93df76de12212820546b2043071.png


a5c926a6c5e0f22c49ae7feef71d7f8f.png


 


See rest of SL shots here: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=10658


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Shredhead    131

The Man From U.N.C.L.E.


220px-The_Man_from_U.N.C.L.E._poster.jpg


 


Biggest hit -1.08Vpk which is -8.52dBV from a WCS


Zooming in on waveform looks like no square waves were used in production.


This is a fairly low level for the sub out.


 


1:42:45


5ca8a4590f4e8ac02073b5a01ef719b3.png


 


1:45:30


8e81e4607103f90c542ce54d1c2ef2a6.png


c92bd4b0c28dc5050cfc6fc96740e918.png


See rest of SL shots here: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=11046


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Shredhead    131

Ant-Man


220px-Ant-Man_poster.jpg


7.1 DTS-HD MA


Highest amplitude at 1.02Vpk


-9.02dB from a WCS


 


30:58


6ec3c1fa7bd7e7ab8883d7c4469691f4.png


 


31:55


33c3be3dd254639fc9a44919baf09d52.png


 


37:15


5b61e353ebdfbe8fade067547806e973.png


 


This is close to the last few film soundtracks in level and bandwidth.  Seems to be the new current trend of mixing film.


No use of square waves and keeping sub level down a good bit from full output potential.


 


See rest of SL scenes: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=11182


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Shredhead    131

Terminator Salvation -director's cut


220px-Terminator-salvation-poster.jpg


DTS-HD 5.1 Track


 


2 times this soundtrack hits 1.34Vpk which is -6.65dB from a WCS


A lot of loud rumble in this one with only a couple


noteworthy hits below 20Hz.


 


0:41.26


c5ceddc3adb5726624349ef897ea2581.png


 


0:43:52


84bf605058eba4a93b7827067364cbdd.png


 


0:46:00


81c6351cc14a9032bd561dbd0b3cc9e9.png


 


1:30:00


55b2dc7a5e50fcbbe645cd23cb29a023.png


 


Rest of speclabs here: http://data-bass.ipbhost.com/index.php?/topic/503-terminator-genisys-discussion-and-poll/?p=11477

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Shredhead    131

Pan


220px-Pan_2015_poster.jpg


 


-9.45dB from a WCS.  UNFILTERED with strong hits at 20Hz and under! 


Intelligent sound design with spread out rumble and strong hits.


Dynamic looking waveform with more than the usual amount of headroom.


 


0:15:20


7759b05121a4a0b01e35400c1e4f4fa9.png


 


0:18:23


4607e271e5a76151acc340443d77de2f.png


 


0:41:56


8f9ab8d281fc671795ee966c603fa7c5.png


 


1:28:05


f94f4d830cf7389f102bca1ca29dad3f.png


 


Rest of SL's: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=11738


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Ricci    652

Looks like another heavy hitter. Tons of 5-20Hz bass in those captures. Why can't Marvel's movies have this kind of mix and extension?

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Bossobass Dave    241

I don't know why, but I'm liking these movies with a twist on the original. This one is visually excellent and has serious low end, used sparingly but expertly, IMO. I also liked Abraham Lincoln, Vampire Hunter and Maleficent. Quirky, well done, well cast and acted and with superb sound.

 

I also love the waveform analysis. Yet another great tool in the Data Bass bag. Props to His Shredness. B)

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Shredhead    131

Minions


220px-Minions_poster.jpg


(Atmos to Dolby True HD)


Weak bass levels with occasional strong transients centered around 30Hz that push it to -6.52dB from a WCS.


Overall a very low level mix.


 


0:02:05


bbd22878608f85bb9212f0615eed8b20.png


 


0:04:35


cffa9e408b4685bccf8ee3945d9a194f.png


 


0:21:34


43f568a8df19c88de7126f277952f5a5.png


 


1:11:58


43b71f0f60b661ee1c7f4c1a43c7a8f7.png


 


1:14:08


cc6d58eb048953eaa08068b988be37d3.png


 


See rest of SL shots here: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=11777


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Shredhead    131

Thanks, no the 7702 was Beastaudio's and I just ran it through some tests.  It's a fine piece of gear but if I remember right, it won't be supporting DTS X and they are planning on coming out with a new model of it that will.  I don't see why they can't fix this with a FW update but I guess it's been out for a while and they want to change it up.  This thread was done on a player's analog outs that don't have problems with clipping even when put through a WCS test (not the OPPO). 

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dgage    67

I don't know why, but I'm liking these movies with a twist on the original. This one is visually excellent and has serious low end, used sparingly but expertly, IMO. I also liked Abraham Lincoln, Vampire Hunter and Maleficent. Quirky, well done, well cast and acted and with superb sound.

 

I also love the waveform analysis. Yet another great tool in the Data Bass bag. Props to His Shredness. B)

 

I concur on the waveform analysis.  I love the knowledge that is so openly shared on this forum.  Great stuff!

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Shredhead    131

Lone Survivor


220px-Lone_Survivor_poster.jpg


DTS HD-MA 5.1


 


The beginning of the helicopter scene is -3.43dB from a WCS which is a pretty hot peak and it is mostly due to a strong


tone at ~6.5Hz.  I can't believe I'm going to say this but this movie should have been filtered.  I think the sound designers


mic'd a helicopter and didn't have the equipment to realize the level that was captured at 6.5Hz.  The peak hold graph shows


the 6.5Hz almost 20dB higher than at 10Hz and easily 10dB above 20Hz.  Meanwhile, the rest of the sounds used in the movie


are filtered in the 20's and are at a much lower level.  This is why I think the peak at 6.5Hz is unintentional.  This is a dangerous


soundtrack to play hot on any sealed system that is full bandwidth capable and I would be hesitant to play it above reference


level on a ported system too unless I was totally confident in the system's HPF. 


 


0:20:03


e543e1b9788595661b1423057d2cfd74.png


 


0:20:03


046f25d77d0c0b082a8c0d5c4920a3f4.png


 


0:20:03 Vs. Sine wave


-Just to show how much more complex a signal the real thing is in comparison to a sine.


May not be too hard for a well designed small signal preamp to reproduce but if you're swinging over +/-100V with an


amplifier driving a dynamic load, limitations in slew rate will start to be seen.


a5cae45bf0e8b789f899245622bb7a10.png


 


0:21:40


25660f3b5e5ca0e200c5acf157b2d415.png


 


1:00:37


-Most of soundtrack peaks close to this lower level (-13.62dB from a WCS)


d7c5b1e40287d1ea41403a8c2351b1be.png


 


1:00:45


63f711ad0f424ed0bebcf07e083ed34b.png


 


1:44:48


-IMO the only other good hit in the movie at the end.  Still barely anything happening down low.


e150ea2992222561281ecd3bc4de8946.png


 


See rest of SL shots here: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=11800


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Ricci    652

Thanks for the in depth analysis of that scene. That is clearly a very nasty signal. In some ways it looks similar to the 10 tone spectral contamination signal I tried for a while except weighted heavily towards the low end. I quit using that test because it was hell on the drivers and amps both and didn't seem to offer much insight into the systems behavior other than the fact that they don't like it other than at very low volume. Will produce VERY quick heating of voice coils. I'd agree with the assessment as well. They likely captured the sound of a helicopter with very high quality gear and simply didn't have the playback equipment necessary to know just how strong the content is below 20Hz. The rest of the movie being mostly a non event below 30Hz seems to indicate so. Either that or they do keep tabs on what people like us say and thought "they want unfiltered bass, we'll give them unfiltered bass!"

 

I ran this on my XXX system the first time I watched the movie and they didn't have an issue but the playback was about -10 which is typically about what I listen to. Might have to see what happens with a bit more level.

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Shredhead    131

The Last Witch Hunter


220px-The_Last_Witch_Hunter_poster.jpg


DTS-HD MA 5.1


 


Strongest hit at 1:14:25 puts this mix at -5.55dB from a WCS


Unfiltered mix with most of the transient energy around 40Hz. 


I like the sound of 40's punch with some ULF tucked into the mix,


I thought it was a nice break from the typical peak at 30Hz mix and


it had well placed hits.


 


0:02:50


a7591fd8dd102a85738370ed63efc7a2.png


 


0:06:14


992fa56909c72fde16beb3716cfc3271.png


 


0:49:10


72849ed951add12230f8de4c35885bb6.png


 


1:14:25


e2f12c5c0554d582d3afd1f7b4719013.png


 


1:31:33


f32e1be73dbeb35433f7e1ca228bd863.png


 


See rest of SL shots here: http://data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/?p=12014


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