Kvalsvoll
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Posts posted by Kvalsvoll
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does that mean there's another 8db in the tank?
Yes.
I am sure there are many soundtracks with higher peak level, what makes this one so special is that this is sustained, constant-level tones lasting several seconds.
Many lfe-effects are made up from something that looks more like pink noise - wide frequency bandwidth, and crest factor may be in the range 6-18dB.
The variation in level and wide bandwith makes it rather hard to notice that the subwoofer system is way above its limits; kind of a forgiving signal.
Example: Skyfall subway ("was that meant for me?"- "No, but this is..").
Transient effects, like cannons, blasts, have a very short initial peak with very high amplitude.
If the initial high amplitude is clipped or otherwise lmitied, this is not something one will easily notice, as you would need a back-to-back comparison with a reproduction that does not limit to be able to tell that something was lost.
Example: M&C cannons, scene in the middle of the film is the best to notice.
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Is putting these settings into a minidsp safe? Doesn't this kill your amp headroom
Not necessarily.
Note that this is not just a bass-boost.
The level of the signal that gets amplfied is very low to begin with - that is why we do the Bass EQ.
This low-level signal is then amplified up to match the level of the rest.
In many cases you will find that the overall peak level has not changed much at all, after applying the Bass EQ.
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Well, I was going to ask a question about whether this method could be applied if you had a minidsp for only the subs and not the LCR or surrounds. Given Fatshaft's experience, I think I'll hold off until I hear more.
The configuration files maxmercy posted are for the nanoavr only.
Other minidsp products can be used for eq, and you can do the eq on the subwoofer system alone.
To get good results with eq on the sub system you should run bass management for all channels.
No, it will not be exactly like individual eq on all channels, but with proper bass management it will be very close for many soundtracks.
The bass eq entries I made have descriptions for minidsp filters, mostly low-shelve.
Those filter coefficients are compatible for all minidsp products.
I have testet a couple of movies running Bass EQ on the subwoofer minidsp, it works very well.
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By your numbers, someone running with the sub trim at "0" and master volume at "0" will clip above 113 dB, which is less than digital full-scale on the LFE channel alone.
Exactly.
With trim at 0, and mv at 0, you will not even get full headroom of the lfe channel alone.
I would think a lot of people run their systems like this, unaware.
If this was interesting I think the moderators/other readers would appreciate if this discussion moved to a new thread in the gear section, as it is kind of OT in the bass content thread.
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This turns out to be quite simple on the Marantz:
- The subwoofer output clips at 4Vrms.
- MV+Trim must be <=-12dB to keep output below clip level at 4Vrms for a highly unlikely 7.1 signal with 0dB level in all channels.
- No combination of signal and trim causes digital clipping before the output clips at 4Vrms.
This means that if you watch at 0dB, the subwoofer trim must be set at -12dB to ensure no clipping is possible.
Here I have -6dB trim for flat, and that is sufficient for practical soundtrack signals.
However, some movies, such as WOTW, Kon-Tiki, will audibly clip if running 3dB hot with trim level at -3dB.
This shows that it definitely makes sense to calibrate subwoofer levels to the lowest possible trim level setting.
Calibrating for 0dB trim will actually loose 12dB headroom before the signal even enters the subwoofer dsp.
This is for my Marantz, other processors/avrs may be different.
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How exactly did you check the Marantz?
I only listened to it, if there is excessive clipping it will be audible.
However, according to the above post, mentioning that trim level can affect headroom, a more extensive analysis should be done to accurately determine what headroom is available, for different trim levels.
This is quite easy to do, only need to monitor the signal out from the processor before it enters the subwoofer dsp.
I find headroom issues to be the largest problem with ordinary avr/processors; they have too high noise floor and trim levels are not sufficient for speaker systems with large dynamics.
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My guess is that the problem arises when we sum the bass into a single SW channel, although it would help if those measuring clipped waveforms mention the method used. Soundtracks are mixed with no bass management (summing).
Measurements of the analog SW out using various discs yields surprising results. Summing signals from sats channels and the LFE channel can cause huge spikes in voltage and clipping in the signal chain so I imagine the same is likely in the digital realm. The SW output, after all, has finite headroom, so the summing aspect needs to be taken into consideration during production.
Just a thought.
Good point, some processors will be fine, though.
I checked this now on a Marantz and all channels at 0dB seems fine.
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Do you have a post BassEQ graph for Ender's Game?
JSS
No, and the peak graph I posted here is from the opening scenes only.
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Ender's Game
Impression:
Improved a lot, from sounding very boomy and rumbling to still very loud in the bass, but now with proper weight.
The bass is quite heavy in this one, with a marked hump around 30Hz, making it sound rather thick, but with too little down low.
Bass EQ fixed that, the balance is better and you can enjoy lots of very low frequency content that was buried just a little too low in level in the original.
It does not hit hard, only a couple of incidents with proper impulses.
The sound track is generally good, no problem watching this at 0dB mv, but run the bass flat, it gets too heavy if you boost it.
Bass EQ:
Low-shelve filter, on bass-managed subwoofer channel:
22Hz +7dB Q=1.4 (MiniDSP new)MiniDSP Bass EQ:
Opening scene original lfe:
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Gravity
Impression:
First, note that many will find this movie quite heavy in the low bass already, and any improvement requires a playback system set up to extend well below 20Hz.
Not a huge improvement, but at least it did not get worse.
Perhaps a litte more natural weight on sound effects like bumps and hits, but not much, I suspect hardly noticeable to many.
In this movie there simply is not much content to retrieve.
The 20Hz is quite strong in this, so the sense of weight and atmosphere is already present.
Below that, there are some effects that could have spectral content lower down, but some of those impacts and bumps are actually made up from the same 20Hz drone, so they act kind of like a drum tuned to 20Hz.
This is also part of the sound design, and artistic freedom must be welcomed, it would be boring if all sound tracks sounded similar.
What is good about this one is the use of surround, the sound follows the characters as they move around you in space.
Why the Blu-ray is 5.1 one can only guess.
This award-winning sound track also has occasional severe clipping of the dialog in the center channel and some in the L and R.
I think this was intentional and part of the sound design here, they are talking over the radio and the added distortion amplifies the sense of distress.
The overall sound presentation is dominated by the todays somewhat LOUD sound design practices, though this is not among the worst ones.
Bass EQ:
Low-shelve filter:
16Hz +6dB Q=1.4 (MiniDSP new)
MiniDSP implementation:
Original LFE:
HS filter 20Hz steep slope, -15..-25dB 10hz.
20hz drone present.
Original LCE:
Severe clipping and limiting in center channel.
20hz drone present in all LCE channels, high level.
Filtered <20hz.
Original SL SR:
Filtered 40Hz, no lf content.
Spectrum shows little content below 20hz.
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Avatar
Impression:
Some scenes improved a lot.
Most notably the flight-scene at 24:00min, and where the big red dragon appears.
Many scene did not contain any ulf, and does not sound much different, but you can choose to see it like that there is variation in how the sound is made, and that in itself makes the sound more interesting in my opinion.
Bass EQ:
Low-shelve filter, all channels:
16Hz +16dB Q=1.0 (MiniDSP new)
MiniDSP implementation:
Original sound track:
lfe:
30hz filter.
no clipping.
occasional content 13-14hz.
c:
filtered 60hz.
no clipping.
no significant lf content.
l r:
filtered 30hz, steep, shelve -20dB.
content all the way down.
much of the ulf content is in the l r channels.
no clipping.
sl sr:
contains filtered ulf content. -
Super 8
Impression:
More impact, more natural sounding effects, this one improved a lot in the lower bass range.
This movie is known for the train wreck scene, but there are several occasions with very impactful hits, where you feel the blasts like a pressure-wave.
Unfortunately the louder sound effects are destroyed by severe clipping, it sounds quite bad.
Bass EQ:
Low-shelve filter, all channels:
17Hz +16dB Q=1.2 (MiniDSP new)MiniDSP implementation:
Original sound track:
lfe:
30hz filtered.
lcr:
30hz filtered.
heavy clipping in all channels.Spectrum LFE channel original and with Bass-EQ:
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Battleship
Huge improvement, but still it does not make wonders out of the rather compressed and loud mastered original sound track.
Sense of weight is improved from non-existing to quite nice.
Also see the RTA spectrum plots in the Why Bass EQ post.
Bass EQ:Low-shelve filter, all channels:
27Hz +12dB Q=1.0 (MiniDSP new)
27Hz +12dB Q=1.0 (MiniDSP new)
MiniDSP implementation:
Peak-Average original:
(Updated 11012015)
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Oblivion
Original soundtrack is quite good, but some Bass EQ at the lowest frequencies makes it even better.
The bass sound sounds more natural and balanced, with much more weight.Impression:
Improves from loud but still overall good to an outstanding, loud, physical immersion.
Bass is a little hot in the mid bass range, could try with a little reduction 30-60hz.
The canyon fight scene improved remarkably good.
Impacts and blasts sound less boomy and more powerful, now you kind of feel it on your whole body.
The ulf was done very well in this film, you just have to dig it out.
There are both subtle, small shakes that you really never hear, you just feel it, and there are those physical moments like the landing scene and the fighting in the canyon.Bass EQ:
Low-shelve filter, all channels:
18Hz +8dB Q=0.9 (MiniDSp new)
MiniDSP implementation:
Peak-Average original and Bass EQ:
Recorded playback from start to coming-in-hot:
Original sound track:
LFE:
Original track is heavily compressed and limited, and filtered at 25-30Hz, slow slope.
L C R, (sl sr sbl sbr):
Original track is compressed and limited, C shows visible signs of heavy limiter distortion.
Filtered at 30Hz, occasional content <30hz exists, sharp slope, shelf type with floor -15..-20dB.
Lots of lfe content in the center channel.
(Updated 16012015)
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How to submit Movies with Bass EQ
Each Bass EQ movie description should have a technical objective description of the equalization, and a subjective impression of how it improves.
Peak-Average graphs of original and Bass EQ filtered gives good additional information, if you have those.The Bass EQ is described by parameters for low-shelve filtering.
Additional screen plot from equalizer software, such as MiniDSP, shows the frequency response and how to implement the filtering.
Example:
Low-shelve filter:
10Hz +10dB Q=1.3
MiniDSP implementation:
The subjective impression is important because the frequency spectrum plots says nothing about how it actually sounds.
The impression should briefly say something about how the Bass EQ improved the sound, and perhaps also inspire others to try Bass EQ on this film.
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How to recognize good candidates for Bass EQ and what to fix
Any movie where sound effects and bass is lacking in weight are potential candidates.
Looking at the Peak-Average graph from the The Low Frequency Content Thread (films, games, music, etc) thread can tell a lot about how a movie sounds.
Kon-Tiki is a film with a good sound track utilizing the whole frequency spectrum, observe that the curve is a slightly tilted line extending all the way down to the very lowest frequencies:
The storm scene has content all the way down:
This film does not need any Bass EQ.
Battleship has met with an accident somewhere in the sound-making process:
There is an obvious drop right below 35Hz, looks like a steep high-pass filter has been applied.
This is something to work on for Bass EQ.
A good target response is likely an approximately tilted straight line, that extends as low in frequency as possible.
Start with applying equalization that bring the Peak-Average curve closer to this straight tilted response.
Evaluation by listening is necessary to determine appropriate equalization, and care must be taken to ensure not to clip the signal anywhere in the chain.
How low in frequency should you try to equalize to flat.
Depends on the original sound design, and whether there is any content to dig out, it may be buried in noise at the very lowest frequencies.
Fixing something destroyed with a 30Hz filter and mangaging to retrieve flat down to 20Hz can make a huge difference.
If you can extend it down to around 15Hz, even better.
Below around 15Hz is questionable, certainly depends on your playback system, as tactile feedback from floor or moving house structure may be required to notice it at all.
The lower you go the greater the risc of amplifying noise instead of usable content, and if you can bring a sound track with virtually no low bass back to life with significant content down to 15Hz, I would say that is a very good achievement.If the filtering was done using a shelve filter it is more likely that there is content to retrieve.
A shelve filter can be recognized by looking for a flat level floor below the first cut-off.
In the Battleship graph you can see the level flats out below 20Hz at around -50dB, this indicates that a shelve filter has been used.
Then you can use an opposite shelve filter to retrieve that lost content.
Gravity, opening scenes (RTA from playback):
This film has a droning, constant tone around 20Hz, as can be seen in the curve.
This is part of the sound design.
The level below 20Hz drops off very quickly, but it is not likely that equalization can bring improvements, because likely there is no content that has been removed.
The relationship between frequency and time dictates that continuous tones, which have a long time span, are narrow in frequency distribution.
Impulse like transients, like cannons and gunshots, have short time span and a wide frequency distribution.
If there are no impulses, there may not be low frequency content to retrieve.
When the Explorer is hit by the debris, there are sound effects added that adds to the sensation of the incident, these sounds are more dynamic and impulse-like:
The spectrum reveals that there is content below the 20Hz drone, and that this content may have been filtered using a steep high pass around 20Hz.
Gravity is another candidate for Bass EQ.
Avatar, flight scene (RTA from playback):
This scene sounds good, the feeling of realism and athmosphere is good.
Right at the end of this scene, where the plane drops down the cliff, there is a sense of weightlessness, making it feel like you are on the plane.
The spectrum reveals why this effect is so good - there is significant content at the very lowest frequencies, peaking around 13Hz.
Avatar, monster stomp-stomp (RTA from playback):
Here the stomps sounds rather boomy and does not have the appropriate feeling of weight and impact.
The spectrum reveals why - the low frequency content below 25Hz is removed.
Considering the previous flight scene, the conclusion is that finding the best Bass EQ for Avatar will be a compromise.
Some scenes could benefit from a huge low-frequency boost, but then other scenes would sound horrible with too much in the low end.
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How to Bass EQ
Update 04.01.2015: Note on q-values for parametric eq on MiniDSP
Bass EQ description for a movie looks like this:
Low-shelve filter:
17Hz +10dB Q=1.3
DSP Implementation:
The parameters for the filter is entered in to the DSP software, and you are ready to watch the movie with improved low frequency reproduction.
The example is shown for implementation using MiniDSP.
If you have a different DSP solution, or other kind of equalization method, the parameters for the filter and the frequency response for the correction is still valid.
You must be able to implement equalization according to the Bass EQ graph for each individual movie.
This can be done in a DSP, if you have something like that in the playback chain.
In a bass-managed system the Bass EQ can be implemented on the subwoofer channel.
This is the easiest way to implement Bass EQ, you simply enter the filter into the DSP already in the chain.
Computer playback is increasing in popularity, and it will eventually be the preferred playback device for all media content.
Then it is likely that equalization can be done very flexible and accurate using a plug-in or built-in processing in the player software.
JRiver media center is an example of player software that can do Bass EQ with individual settings for each move.
A simple graphical equalizer or bass tone control will not be able to provide Bass EQ.
To verify your equalizer setting you can play a noise file and compare the frequency responses - the unfiltered noise should be flat, and noise with Bass EQ should look similar to the Bass EQ curve.
There are two types of analyzers - one will show a flat response for white noise, the other will show flat for pink noise.
An ordinary spectrum analyzer presents energy distributed linearly across frequency, so that the energy between 10 and 20Hz is the same as between 10000 and 10020Hz.
Since hearing is logarithmic, it is better to use a real-time analyzer, which presents content as equal energy for each octave band, so that 10-20Hz is similar to 10000-20000Hz.
The spectrum analysis in Audacity is of the former type, and requires a white noise signal for flat response.
The RTA (Real-Time Analyzer) in REW is of the latter, showing flat for pink noise signal.
REW also has a Spectrum analysis option, which shows flat for white noise.
For most movies the Bass EQ is best to implement using a shelve filter.
In many movies, especially the ones that responds well to Bass EQ, the in-studio filtering was done using some kind of shelve filter, the Bass EQ will then invert that.
A shelve filter with adjustable frequency, slope and gain level can fix it.
Some movies require a very large boost at low frequencies, perhaps in the order +20dB gain below 20Hz.
This requires careful attention to what you are doing.
If such a filter is left in unintentionally, and you play a movie with flat full frequency content, something will overload.
Some movies are quite heavy in the mid bass region, equalizing this down will gain some headroom for the low bass as well as improving the overall spectral balance.
A low-shelve filter with high Q/sharp slope will do this, the response will drop down below 0dB in the range above where the slope ends.
If there is noise at frequencies below usable output, say around 10Hz and below, then this can be removed using a high pass filter, and some more headroom is gained.
If the sound track is mixed very loud and dynamically compressed, there may not be enough headroom for the low bass we bring back, and the only solution is to reduce the level before applying the Bass EQ.
The lost gain is restored later in the chain, perhaps as simple as adjusting the master volume.
Exactly how this is done depends on what it used for equalization; different dsp and software may require different approaches.
If you equalize on the subwoofer system, this headroom issue should not be a problem.
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Why Bass EQ
When movies are mixed in the studio, the sound will be adjusted according to what they hear in that studio.
Sometimes limitations in the playback equipment, such as speaker system, will lead to adjustments that will compromise sound quality.
Typical examples of such undesired adjustments are high-pass or shelve filtering that removes the lowest frequency content.
On a limited system this may sound better, because the removal of content that can not be reproduced anyway will increase headroom for the mid and upper bass frequencies.
When played back on a full frequency range system the filtered version looses weight and impact, and also tend to sound less natural.
If this filtering is done in one of the very final stages of production, then it is a good possibility that at least some of the filtered content can be retrieved.
This is what Bass EQ tries to do.
The better your playback system is, and if you also like it loud, like 0dB/reference, then the difference will be very significant, and on some movies the whole experience is lifted to another level.
But also if you play at lower volumes, say -20dB, perhaps you have some smaller but still nice and good quality subwoofers, then the difference will most certainly be very noticeable.
This is not only about more shake and physical impact at house-wrecking volumes, the overall sound quality is improved when the natural wide frequency range is restored.
Example frequency spectrum plots playing this scene from the movie Battleship:
Battleship, original and Battleship with Bass EQ playback:
There is a huge difference in output at low frequencies, and listening easily reveals that the perceived increase in sound quality is significant and very far from subtle.
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Would it not be great if you could bring back the lost bass in you favourite movies?
Well, perhaps you can.
By applying equalization customized for each movie during playback, it is possible to dig out some of the low bass lost due to filtering and processing in the studio.
Why Bass EQ
How to Bass EQ
How to recognize good candidates for Bass EQ and what to fix
How to submit Movies with Bass EQ
Movies improving with Bass EQ
This is the list of movies that can be improved by applying Bass EQ:Godzilla: King of the Monsters
Transformers:Revenge of the Fallen
Transformers:Age of Extinction
Valerian and the City of 1000 Planets
coming soon:
Master & Commander BluRay
Tron:Legacy
Batman Begins
The Dark Knight
Fight Club
Star Wars: The Phantom Menace
Star Wars: Attack of the Clones
Saving Private Ryan
Wreck-It Ralph
Top Gun
Alien Resurrection
The No Hope Movies
Some movies can not be improved:The Hobbit: An Unexpected Journey
Update sep 16 2014: Changed Bass EQ implementation and description method, updated movie entries.
Update jan 11 2015: Filter parameters for early entries updated to match new MiniDSP implementation.
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Is it possible to get the Norwegian version in the US w/ English subs?
JSS
Yes, but you will have to make it yourself.
By adding the English subtitles from the English version, to the Norwegian 7.1 version, of course this will only work if the versions are similar part from the audio and subtitles.
Not likely that anyone would go through that much trouble just to get the 7.1 soundtrack.
I checked my Norwegian version now, and find that there are no English subtitles.
I also had no idea that the other versions would have a 5.1 soundtrack.
Well, the media business never disappoints when it comes to finding new ways to fail and destroy excellent products, so I guess it should not come as a big surprise that they managed to screw it up.
From what I read in here I find it likely that the 5.1 soundtrack is still very good, and it is likely that it is encoded in Pro-logic and then you will not miss anything significant.
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Rest of world, I believe.
Yes, sorry about that, ROW = Rest of the world.
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Kon-Tiki:
You should try to get the Norwegian release, it has a real 7.1 channel soundtrack.
Seems like they released the "ROW"-version with 5.1 only, at least it looks like the sound is still very good.
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I took the liberty of posting a reference to the analysis of STID on the "End the Lodness War"- group on fb:
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The disease has spread to movies as well, reports indicate that the new movie Star Trek Into Darkness is severely clipped, and compressed.
Given the size of budget for this kind of movie, this failure is a quite remarkable achievement. Disasters never has one single cause, this requires three failures; one - the use of an incapable sound monitoring system, two - decision makers with severe hearing loss, three - incompetent sound engineers with no knowledge of even the most basic signal processing theory.
This movie should have real demo potential, instead it is a movie I will never consider spending my money on.
Reference:
data-bass.ipbhost.com/index.php?/topic/12-the-low-frequency-content-thread-films-games-music-etc/page-65--------
I am very, very, dissappointed.
The Bass EQ for Movies Thread
in Bass Content
Posted
If you already have the 2x4 you can already try the setting maxmercy posted.
Assuming the dsp is on the subwoofer system, apply all the filters listed for the lfe channel.
This will leave out some of the gain for the rerouted bass from l/r channels (because the filter required for those are different from the lfe), but should still give you an idea of what kind of improvement this is.
But be carfeful, those are very high gains in the ulf frequency range, make sure you don't accidentally play something like WOTW or Kon-Tiki, and try it out at a lower mater volume level first.