The New Master List of BASS in Movies with Frequency Charts - Page 14

The Lord Of The Rings: The Fellowship Of The Ring (blu-ray, DTS-HD Master Audio 5.1)


That huge -2db spike at 38hz has me worried that it clipped so I'm double checking now, trying to find the scene where it happened.

update: No it wasn't clipping. It's the scene at 46 minutes into the movie where the hobbits are hiding under a tree root and a ghost king on his horse almost finds them. The loud event lasts for a little over 10 seconds and is accompanied by a strong under -14db 23hz signal.

Just watched some scenes of the new extended edition bluray LOTR wow is all i can say the audio quality is awesome and the picture quality is great as well its a must buy.

For all of you in canada HMV has it for $64.99

Red Cliff is awesome! It has the best picture quality of probably anything I have seen. The sound quality is great, too.

Thanks Leto! I have SL all set up as you describe. The only issue I have is getting the audio to SpecLab. What I have is the LD audio was ripped digitally and 'muxed' into DTS-HD MA as not to lose information through re-encoding to DTS 1.5mbps. So this file, and all of my other Blu-rays are stored on my server with untouched video and HD audio, bitstreamed via HDMI to my receiver. If I could find a way to playback these through a software player outputting audio to a device SL can monitor, it would be very easy to graph a ton of films. I imagine though I'd have to use a filter that decodes the HD audio before sending it to an audio device SL can monitor?

Of course this is assuming you can even monitor output devices in Windows 7?

EDIT: Virtual Audio Cable seems to be working for me.

The Lord Of The Rings: The Two Towers (blu-ray, DTS HD-Master Audio 5.1):

Your levels still look to be on the high side.

Here is my chart of the same scene (near the 46 min mark).

Left side is the single LFE channel. Right side is the mixed L, C and R channels.

Throughout the movie, there is no infra on the LFE channel. All infra is just a part of the sound effects placed on the main channels.

I'm sure it didn't clip at all during Fellowship Of The Ring. My charts show all channels.

Your levels as shown in the amplitude bar graph still look to be a bit high.


I use test tones of known dB FS level to calibrate. A test CD is useful for this. Here is a SL calibration test chart taken with a 100 Hz sine wave @ -20 dB FS level.

Not sure how that's possible, unless there are some odd settings in Hypercube doing it. Here are my Hypercube settings:



Maybe I'll try setting it to native processing one of these days instead of DirectShow.

Picked up sucker punch against better judgement but was pleasantly surprised at the extended version. Maybe since I went in with low expectations lol.

I would say 3.5-4 on LFE, some scenes really had some nice action to them.

Are you saying that anything at or louder than -20db should be clipping?

No, I am saying that -20 dB is indeed -20 dB for one channel with that calibration. Clipping occurs above 0 dB FS for a single test sine wave. Note that real wide band program material is not the same as a sine wave test.

The problem occurs when you use multichannel sound. When you add 3 channels of signal plus the LFE signal together, your peaks can be up to a theoretical +15 dB FS. Signal levels are reduced in a mixer built in to the DD decoder, so the dB numbers on the waterfall and spectrogram are no longer calibrated when more than one channel is used at a time. Overload AGC may also be applied if the combined signal levels get too high.

A second problem with SL is that the ampliitude graph on the right hand side is linear and not a log scale. Your peak signal should hardly ever be much over 50% (about 6 dB down from clipping).

REW dB FS generated signals also are calibrated to read as calibrated for SpectrumLab in my system.

Can you translate that into English for me please? Are you saying that my waterfall charts are/show clipping? Before I make waterfalls, I check my levels with Goldwave's vu meter to make sure i'm not clipping. I set the level to the highest I can set it using what I think is the loudest scene in the movie, without clipping. Are you saying Goldwave is wrong and that I should use another vu meter?

Turn the volume down so the peaks on the SpectrumLab amplitude graph on the right hand side are just a bit above the 50% level. That is a ballpark chart of the combined signal level (AKA linear amplitude). Near 100% is too high.

The 50% amplitude level gives you about 6 dB of headroom on the dB scale.

I am using the Voxengo Gliss EQ VST plugin with J. River Media Center 16 to analyze peak output. It's spectrum analyzer is very accurate and shows the digital representation of the audio stream. To check the accuracy, I used soho54's Audio Test DVD and played test tones for the left speaker at 5, 15, 15, 20, 25 and 30 Hz. I then activated bass management and played them again while viewing the LFE channel. As expected, the volume was lower since I output the LFE channel at -10 dB to maintain headroom for the other channels.

I used a 200 Hz crossover on all channels with the low pass at 12 db/octave and the high pass at 48 dB/octave. I set the spectrum for a flat power spectrum density, like Speclab, instead of having each octave contain an equal amount of noise power. In other words, pink noise will show a downward slope from left to right at about -3dB per octave while white noise will show as flat.

The dB scale on the right of the seems to be high by 10 dB. I couldn't find any setting to adjust it. soho54's test tones are recorded at -20 dB, but show as -10 dB.

Here are the left speaker test tones at 5, 10, 15, 20, 25, & 30 Hz:



Here is the LFE channel with bass management on while playing the left speaker test tones:



Here is a clip from Red Cliff Part II from 1:41-2:02 during the naval battle scene showing maximum output. Lots of low bass! Interestingly, all of the low bass is recorded in the front three channels instead of the LFE channel. Also, the LFE channel has content up to 4 Khz. It isn't filtered at 100-120 Hz like most other movies.:

How does it look now? This is the same scene around the 46 min mark in Fellowship:

Looks like clipping is impossible at those levels. AGC can not be activated at those levels either. Levels are not too high and not too low - just right!

Now your color choice for the waterfall is another matter. But that is a preference type of thing.

Just re-evaluated Live Free Die Hard. Ok, ok, it's a five star

Peaks will never be at +15dBFS, theoretically or otherwise.

You're confusing single frequency peaks with total dBSPL peaks of an effect.

SL is fine when bass management is used in the player and the signal is taken from the SW out, which is how it should be done except to satisfy a curiosity as to where a given sound design team may have chosen to place the LFE.

Low end is placed in the sats to keep DD backward compatible with DPL, which is why BM should be used in all HTs... and with SL.

No +15dBFS peaks. Not happening. Please stop confusing people who are contributing to the thread.

Bosso

You are confused there Bosso. SL is only accurate for dB FS levels if you do two things. First you must calibrate the system. Second you must only playback one digital channel at a time with no reduction of sound levels internal to a decoder/controller (receiver/PC software-hardware).

The use of a receiver, BM and SL does not give you accurate dB FS numbers by frequency for multi channel sound. Never going to happen. Multi channel sound levels are reduced by about 15 dB internal to the receiver in order to prevent clipping.

No, I am not confused about the difference between signal level peaks in the amplitude chart (AKA total dB SPL peaks of an effect) and individual dB levels as shown on the waterfall. You can make the dB FS numbers on the waterfall come out to be any number that you want to without changing signal levels in the system and the SL amplitude chart.

For the comparative electrical and acoustic method that you use for your subwoofer tests, accurate dB FS calibration is not important. Just realize that single frequency bin peaks numbers without calibration are just relative numbers.






Sure. They don't mix movies for theatrical release. They mix them for downmixing in a DVD player. Never going to happen.

There is no consistent way that movies are mixed as can easily be seen is SL. A perfect example is the lightning storm of WOTW. Outside of the houses the bass was mixed one way, and inside of the house the bass was mixed a different way. That was not done for any reason realted to what you are talking about.

By the way, which sound effect sounds better in your sytem. WOTW lightning storm inside or outside of the house? My system is only good to 18 hz, so what do I know about how each mix sounds / feels on a full range system.

How about we get back to movies with bass and times when to crank it up if you want start a thread dedicated to waterfalls Etc.

I Agree!

I don't think that's necessary, I think it's a good thread to do either and discuss bass in movies.

I think the bass average chart should be a mandatory inclusion from now on, imho. Its VERY useful. I mean, we have had this type of thread for years now for the specific case of looking for movies or scenes with bass. Having a bass average for a bassy movie is just as important as seeing the detail of a single moment that has bass. Should also really help narrow down and categorize these bass charts. Now we can say, "hey, this is movie is bassy as hell but there is nothing worthwhile below 20hz." or something like that. With the bass averge chart, you now can see the overall bass 'tone' or weighting of the movie. Does this movie have persistent <25hz content? Hell yes it does, look!

The Lord Of The Rings: The Return Of The King (blu-ray, DTS-HD Master Audio 5.1) :


This was my first one with J_Palmer_Cass's suggestion of setting the level to a little over 50% amplitude. First thing you'll notice is that instead of the long term average line hovering around -35db for a bit from 30hz to 60hz, it now hovers closer to -40db.

Curve wouldn't be effected from the amplitude change, and from what maxmercy said a while ago the most important thing about these bass average charts is the curve. So I wouldn't need to redo my previous bass average charts.

Agreed. I don't know if maxmercy was the first to post a bass average chart in these threads but I find it very helpful. From a single screenshot you get so much information. With a quick look at a bass average chart you can tell whether the movie is closer to War Of The Worlds than Close Encounters Of The Third Kind.

Exactly.

SL is accurate relative to the color scale regardless of calibration accuracy, which is not necessary. The offset feature in SL is sufficient to get a good enough relative result.

All properly implemented BM, whether in the player or the AVR, adds the corrective boost after conversion to analog of the summed SW signal, which is then sent to the SW output.

You can search USPTO for Cirrus Logic's 20 years old patent for digital BM and verify. An excerpt:


From Audioholics:


If one's player doesn't properly do BM before feeding the SW output, then that's a separate issue to be dealt with by the one who owns such a poor quality player, such as using the AVRs SW out.

There will never be peaks of +15dBFS coming from the source regardless of the feed method.


Dolby Guidelines:




From a DVD players manual:


Confirming that during downmix, the LFE (.1) channel is discarded. Thus the recommendation from Dolby not to place all LFE in the LFE channel.

Looking at the example of WOTW lightning strikes; the outdoors strikes have far more upper frequency content. When they move indoors, the upper frequencies are attenuated by the fact that they are insulated from the upper frequencies by the enclosed house. This is exactly what happens in real life during an actual thunderstorm, although the WOTW lightning strikes are not actually lightning, but an alien transport method. It's just good sound design

4-10 Hz doesn't 'sound' like anything. It 'feels' quite nerve wracking the first few times you experience it.

Bosso

In that case, I'm probably done contributing. Don't have an easy way to do it while I'm in there watching a movie, and I just don't have the time to do it afterwards.

More trouble than it's worth for me.