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Ukko Kari

Real life sounds - instantaneous loudness

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Ukko Kari    2

I found Tom Danley's posts on this subject very enlightening, our ear / brain is not as linear as one would think. Very short duration events that seem to be of average or ordinary levels can be incredibly loud, when one measures the peak output from a microphone on an oscilloscope.

https://www.audioasylum.com/cgi/vt.mpl?f=hug&m=178121

If the forum does not allow direct linking this is the thread title on the Audio Asylum High Efficiency forum, the search function should bring it up:

How to reproduce the full dynamics of a scissor cutting paper without clipping

 

 

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Ricci    637

I've read some things on this topic over the years. I don't doubt that the peak levels produced by some everyday events are quite a bit louder than expected. Dropping a glass on a tile floor, slamming a car door, acoustic drums and cymbals, etc. To me the issue with the entire discussion which I never saw mentioned in that thread is the fact that none of the recordings contain that much dynamic range to preserve the peaks accurately. There might be some rare niche recordings but the typical mixes we listen to for music, broadcast and movies do not. Reproducing a car door shutting or dropping a dinner plate on the floor extremely convincingly is cool and all, but what recordings will allow you to take advantage of such playback capabilities? Some music should have 30 to 40dB dynamic range in the recording but let's say some albums actually get mixed like this to preserve ALL of the dynamics. So your average playback level of digital media has to be turned up 30-40dB to reach the same average playback levels. What happens when you forget to turn the volume down and something as badly compressed as Death Magnetic comes on with the average level 30-40dB higher? It could also cause issues with system noise floor having to use so much gain.

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Ricci    637
2 hours ago, MemX said:

Only very few tunes seem to have Dynamic Range over 30, going from this database!

http://dr.loudness-war.info/album/list/dr-max/desc

 

Right...That's what I mean. If you preserve incredibly high dynamic range with digital media that means your average level is going to be very low volume/signal strength, requiring much more gain to get the average sounds to a typical playback level. I wish there were more recordings like that. Just turn up the volume  and the problem is solved. But the problem is, if you attempt to play a regular heavily compressed song after, it will blow your head off and make the dynamic recording sound weak in comparison. That's exactly how the loudness war started. Get the average level as high as possible. Louder=better or more noticeable.

I'd like to see groups make 2 mixes. The squashed "radio" track and a much lower average volume mix with more dynamics.

I see this issue as separate from your speaker system being capable of producing huge short term output. I consider that a reasonable goal that improves sound quality on a number of fronts.

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SME    201

Lack of content with better dynamics is a real bummer.  I also wish groups would do two mixes.  At least some music BDs have decent dynamics.

High dynamic range mixes could even benefit electronic music, in which e.g. the bass instruments could be mixed a lot hotter.  This way, listeners with capable equipment (including a lot of car listeners) could enjoy more bass without having to compromise the quality of the rest of the track by using an excessively boosted sub level or tilted curve.  Most bass instruments, even in electronic music, have harmonic components going all the into the upper mid-range, which have a big impact on how the sound is perceived.  When one boosts only the sub frequencies, much of that texture is lost, and it can hurt the impact of the sound.

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Ukko Kari    2
9 hours ago, Ricci said:

Right...That's what I mean. If you preserve incredibly high dynamic range with digital media that means your average level is going to be very low volume/signal strength, requiring much more gain to get the average sounds to a typical playback level. I wish there were more recordings like that. Just turn up the volume  and the problem is solved. But the problem is, if you attempt to play a regular heavily compressed song after, it will blow your head off and make the dynamic recording sound weak in comparison. That's exactly how the loudness war started. Get the average level as high as possible. Louder=better or more noticeable.

I'd like to see groups make 2 mixes. The squashed "radio" track and a much lower average volume mix with more dynamics.

I see this issue as separate from your speaker system being capable of producing huge short term output. I consider that a reasonable goal that improves sound quality on a number of fronts.

While I get that Joe Q. Public doesn't want to ride the volume control, it would be nice to have more dynamics for the people with adequate playback capabilities.

 

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Infrasonic    149
On 8/4/2017 at 7:10 AM, Ricci said:

Right...That's what I mean. If you preserve incredibly high dynamic range with digital media that means your average level is going to be very low volume/signal strength, requiring much more gain to get the average sounds to a typical playback level. I wish there were more recordings like that. Just turn up the volume  and the problem is solved. But the problem is, if you attempt to play a regular heavily compressed song after, it will blow your head off and make the dynamic recording sound weak in comparison. That's exactly how the loudness war started. Get the average level as high as possible. Louder=better or more noticeable.

I'd like to see groups make 2 mixes. The squashed "radio" track and a much lower average volume mix with more dynamics.

I see this issue as separate from your speaker system being capable of producing huge short term output. I consider that a reasonable goal that improves sound quality on a number of fronts.

This is the part of all of this that drives me up the wall...

Simple. There is a button on a consumer device that will electronically deal with "blow yer head off" mixes. It's really not that unreasonable task to put on the consumer. While we can be dumb, we are also a lot more in tune with advanced electronics and user interfaces as we deal with them all our life. When someone purchases a new audio device there is bound to be some set up of sorts. Hell, to be even more real about it, these days almost everything has a sign-in and is part of some eco-system. So it's not unreasonable to ask once while putting together some new device you want to use if you want dynamic range compression. Very simple thing that could possible end this crap. Nope. They gotta do if for you.

 

Keep the original on disc... and then let us choose to squash it.

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lilmike    36

"Keep the original on disc... and then let us choose to squash it."

But, louder is better...

It just blows me away that we use such a small fraction of the dynamic range capability of the recording medium. A CD is close to 100 dB, yet the best recordings are barely 30 dB. A Blu-Ray is theoretically capable of 144 dB, yet we see about 35 dB used in most cases.

According to Wikipedia, human hearing has a 140 dB dynamic range.

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MemX    94

I know it's completely subjective, but I find that the radio and other 'flat' tracks with little dynamic range are very wearing to listen to - sometimes I have to turn off and swap to some classical music, simply because it seems to be a lot better recorded, with a much larger dynamic range, and gives my ears a break.

 

It's much the same with films that are the victim of the loudness wars - I'm up and down on the volume controls throughout Star Trek: Into Darkness, whereas something like Oblivion is set-and-forget.

 

What I find most interesting is that if one picks up some CDs from back in the 80s, such as those listed on that link I posted earlier, they do have dynamic range and are recorded a lot quieter than modern stuff - I presume because the loudness wars hadn't started and people actually just recorded stuff how it was played.  So, despite the audio systems being (I assume) a lot lower in quality than the stuff one can buy nowadays, they actually had the quality of recordings and had to exercise their own control over their volume knobs.

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dgage    67

You're getting real close to being that old guy yelling "get off my lawn."  "Back in my day..."  LOL!  But I agree.  One of my favorites is still Dire Straits - Money for Nothing as it was one of the first CDs where I could tell it was recorded better than most of the other records of the day.  Dynamics in spades.

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Kvalsvoll    71
On 7.8.2017 at 8:04 PM, lilmike said:

"Keep the original on disc... and then let us choose to squash it."

But, louder is better...

It just blows me away that we use such a small fraction of the dynamic range capability of the recording medium. A CD is close to 100 dB, yet the best recordings are barely 30 dB. A Blu-Ray is theoretically capable of 144 dB, yet we see about 35 dB used in most cases.

According to Wikipedia, human hearing has a 140 dB dynamic range.

That may be true, but that 140dB range does not apply for short time spans, because the ear has a built-in compressor that adjusts sensitivity according to exposed sound pressure level. If a very loud 140dB peak occurs, the sensitivity is immediately reduced, so that sound at very low spl can not be heard until the ears recalibrate, and that takes some time.

Purpose of this mechanism can be to protect hearing, and also is the mechanism that actually makes it possible to have such a wide dynamic range.

How large is the actual dynamic range, at a given moment, for a given spl exposure? Perhaps someone knows, I am sure there has been lots of research conducted on this. This relationship has attack time, hold delay, depends on peak vs rms level.

This has consequences. We see that hearing is not a time-invariant system, because the output (what we hear) depends on what happened before in time.

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Kvalsvoll    71

Or, there may not be that much research done on this at all. If the subject has little interest outside audio/hifi - because audio research has always had a tendency to focus on technical properties that may not be very relevant, and less on hearing perception mechanisms.

I did a test to find audibility limits for distortion not long ago. Look at these numbers.

440hz:

 

60dB

2h -34dB 2%

3h -50dB 0.32%

4h -50dB 0.32%

5h -53dB 0.22%

6h -50dB 0.32%

8h -58dB 0.13%

 

70dB

2h -34dB 2%

3h -50dB 0.32%

4h -54dB 0.2%

5h -65dB 0.056%

6h -64dB 0.063%

8h -72dB 0.025%

 

80dB

2h -34dB 2%

3h -34dB 2%

4h -43dB 0.71%

5h -65dB 0.056%

6h -72dB 0.025%

8h -76dB 0.016%

 

This data suggests that the presence of a 80dB tone does not reduce hearing threshold when the frequency of the other low-level signal is sufficiently far away in frequency. Because you can see that detection level for higher order harmonics is lower in percentage as the volume increases, and if you plot this data into a frequency response chart, you can see that the detection level remains constant at threshold of hearing around 0dB, with a masking around the fundamental tone. The masking follows the level of the fundamental tone, but far away the detection level remains the same, regardless of fundamental tone loudness. The 80dB fundamental does not reduce hearing threshold, it only masks around the tone.

Then we understand 2 things:

- Dynamic range is at least 80dB for 80dB sound

- Louder means more detail and more revealing to faults in the audio chain

 

So, why did I not test for even louder fundamentals, say up to 120dB? That data could be interesting to have. When I did the test, it was for a different purpose, and 60 to 80dB was sufficient. Louder presents some challenges - more difficult to ensure that the only distortion present is what is being tested for, and listening to tones louder than 80dB up into the midrange is actually so loud it is quite unpleasant.

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Ukko Kari    2

Kvalsvoll: very interesting results, it mirrors other information that I have come across in the past, where 2nd order harmonics are relatively benign in comparison to higher orders. From your data, we can see that higher orders of harmonics are deleterious, and the ear can easily distinguish these from the original signal.

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SME    201

I bet if this experiment were repeated with subwoofer tones, the trends seen would be even more extreme.  The other night, I heard another system with some JBL subs, ported to 25 Hz or whatever, and I couldn't believe how loud they were.  My own subs at the same SPL are barely there.  When bass is reproduced cleanly, there's remarkably little to hear.  It's almost all feeling.

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Ukko Kari    2

Harmonic distortion in my experience makes a subwoofer seem louder than it actually is. Picking a frequency that most commercially available ( Best Buy, etc ) subwoofers can reproduce at a decent level, say 25 hz, can result in 25 hz + 50 hz + 75 hz being reproduced. An SPL meter will integrate these tones and show a high level, however that does not mean the device is capable of reproducing cleanly 25 hz at that level.

 

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Kvalsvoll    71
1 hour ago, Ukko Kari said:

Kvalsvoll: very interesting results, it mirrors other information that I have come across in the past, where 2nd order harmonics are relatively benign in comparison to higher orders. From your data, we can see that higher orders of harmonics are deleterious, and the ear can easily distinguish these from the original signal.

When viewing the results plotted in a fr chart, it becomes obvious and simple - there is masking around the fundamental, and the rest is audible as if the distortion components played by their own, with no fundamental.

A strange observation on thew 2h is that the phase of the harmonic affects perception, and it is possible to find combinations of level and phase that actually makes the tone seem more clean.

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Kvalsvoll    71
30 minutes ago, SME said:

I bet if this experiment were repeated with subwoofer tones, the trends seen would be even more extreme.  The other night, I heard another system with some JBL subs, ported to 25 Hz or whatever, and I couldn't believe how loud they were.  My own subs at the same SPL are barely there.  When bass is reproduced cleanly, there's remarkably little to hear.  It's almost all feeling.

Subjectively, it is more feeling, because the higher harmonics mask the fundamental.

The distortion test was only down to 80hz. I did a different test for detecting threshold of hearing, and found that you always hear the tone before you feel it, even well below 20hz. I tested down to 10hz.

If there is interest in it, I can find the results and notes and post them here.

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maxmercy    330

Interest confirmed.  I have found that in my last room, on a concrete slab, I could hear 8-10Hz without a tactile sensation.  It was a 'pressure', more than a 'sound', almost as if your head was submerged in liquid.  You can see the drivers moving, but can barely 'hear' anything, no floor shaking or pants-flapping, yet it sounded different.   Under 5Hz, I didn't hear anything, just saw cones moving, and probably not enough to be audible (my system is not that capable).

JSS

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SME    201
9 hours ago, Kvalsvoll said:

Subjectively, it is more feeling, because the higher harmonics mask the fundamental.

The distortion test was only down to 80hz. I did a different test for detecting threshold of hearing, and found that you always hear the tone before you feel it, even well below 20hz. I tested down to 10hz.

If there is interest in it, I can find the results and notes and post them here.

Yep.  When listening to pure tones, one hears before feeling, but for typical mixed content, the sub bass mainly contributes feeling, unless the sub is producing a lot of harmonics on its own.  The subs I heard the other night were obviously doing that, and while it impressed the audience with how loud they were, it was a totally different experience from, for example, my viewing of "Thor" last night, which probably involved similar SPL or more.

Actually, there was a kind of funny moment while I was over at the place with the JBL subs.  The host played the Dolby Atmos "Amaze" demo, which has a few effects with modest ULF subharmonics.  Right before the part which there's a time lapse of storm clouds and some words like "thundering bass", I told him "the next effect has 14 Hz in it".  Then the effect hit and the whole house shuddered and there was a loud "THUNK" after which the bass ended abruptly before the effect was done.  Then I saw him running over to the system to turn it down because it had slammed the subs into the limiter.  :)  I wonder if he bottomed the subs on that one?  Whoops.

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Kvalsvoll    71
18 hours ago, maxmercy said:

Interest confirmed.  I have found that in my last room, on a concrete slab, I could hear 8-10Hz without a tactile sensation.  It was a 'pressure', more than a 'sound', almost as if your head was submerged in liquid.  You can see the drivers moving, but can barely 'hear' anything, no floor shaking or pants-flapping, yet it sounded different.   Under 5Hz, I didn't hear anything, just saw cones moving, and probably not enough to be audible (my system is not that capable).

JSS

I can start a new thread on this, the distortion experiment can also be included there. I will then explain how the experiments were done, the results make no sense without knowing the procedure and limitations.

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Kvalsvoll    71
16 hours ago, SME said:

Yep.  When listening to pure tones, one hears before feeling, but for typical mixed content, the sub bass mainly contributes feeling, unless the sub is producing a lot of harmonics on its own.  The subs I heard the other night were obviously doing that, and while it impressed the audience with how loud they were, it was a totally different experience from, for example, my viewing of "Thor" last night, which probably involved similar SPL or more.

Actually, there was a kind of funny moment while I was over at the place with the JBL subs.  The host played the Dolby Atmos "Amaze" demo, which has a few effects with modest ULF subharmonics.  Right before the part which there's a time lapse of storm clouds and some words like "thundering bass", I told him "the next effect has 14 Hz in it".  Then the effect hit and the whole house shuddered and there was a loud "THUNK" after which the bass ended abruptly before the effect was done.  Then I saw him running over to the system to turn it down because it had slammed the subs into the limiter.  :)  I wonder if he bottomed the subs on that one?  Whoops.

I agree about the feeling-part for low freq - hearing is focused on the higher frequencies, so the lows knid of add power and weight to it all.

Commercial subwoofers use to have limiters to avoid possible damage, because most people do not scan content with a spectrum analyzer before watching, actrually, most people do not know what spectrum analyzer is, and neither should they need to.

The Amaze demo is great, but not for the bass, the "powerful bass" moment is only a distorted, rumbling mess. And if the system can not handle the lows on this one, something with heavy low content will be a disaster.

 

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Ukko Kari    2

With loud low bass in a vehicle and could discern 15 through 11 hz as distinct different notes, however under 10 hz, it was all just pressure on the ear drum, like you were underwater, having jumped into a pool.

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dgage    67
7 hours ago, Kvalsvoll said:

I agree about the feeling-part for low freq - hearing is focused on the higher frequencies, so the lows knid of add power and weight to it all.

Commercial subwoofers use to have limiters to avoid possible damage, because most people do not scan content with a spectrum analyzer before watching, actrually, most people do not know what spectrum analyzer is, and neither should they need to.

The Amaze demo is great, but not for the bass, the "powerful bass" moment is only a distorted, rumbling mess. And if the system can not handle the lows on this one, something with heavy low content will be a disaster.

 

Did you read where we found out Lone Survivor's minute-plus long helicopter scene (ch 4-6?) had a 6.7 Hz pseudo sine wave about 10 dB hotter than the rest of the sound track?  Almost blew up 2 of my test Mariana 24s that didn't have limiters. :)  Apparently sound engineers don't know what a spectrum analyzer is either. :)

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SME    201
9 hours ago, Kvalsvoll said:

I agree about the feeling-part for low freq - hearing is focused on the higher frequencies, so the lows knid of add power and weight to it all.

Commercial subwoofers use to have limiters to avoid possible damage, because most people do not scan content with a spectrum analyzer before watching, actrually, most people do not know what spectrum analyzer is, and neither should they need to.

The Amaze demo is great, but not for the bass, the "powerful bass" moment is only a distorted, rumbling mess. And if the system can not handle the lows on this one, something with heavy low content will be a disaster.

 

Yes.  The system had apparently been calibrated using JBL's new SDP-75 processor only hours before, and it sounded like the calibration had set the subs to run real hot, perhaps even boosting them below their tuning.  That's strange because the system is supposed to rely on data about the limits of each sub to avoid excessive boosts.  I'm sure it didn't help that the demos were seriously cranked too, probably beyond cinema reference level at the front seats.

5 hours ago, Ukko Kari said:

With loud low bass in a vehicle and could discern 15 through 11 hz as distinct different notes, however under 10 hz, it was all just pressure on the ear drum, like you were underwater, having jumped into a pool.

That's pretty much what I experience in my room.  Except that at 11 Hz, the floor shakes too much to make a fair judgment.  Below 10 Hz, I'm not sure I'm able to get enough output for any real pressure from sine waves, but I might get some from transients.  I still need to do the HPF test with the Darth Vader cruiser clip in "Rogue One" with BEQ.

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Kvalsvoll    71
12 hours ago, dgage said:

Did you read where we found out Lone Survivor's minute-plus long helicopter scene (ch 4-6?) had a 6.7 Hz pseudo sine wave about 10 dB hotter than the rest of the sound track?  Almost blew up 2 of my test Mariana 24s that didn't have limiters. :)  Apparently sound engineers don't know what a spectrum analyzer is either. :)

Always a risc of blowing something when you develop and test new equipment. This scene is fine on the horns, you can see the cones moving, but you don't hear a thing, and nothing is overloaded. It is very possible that they did not know it was there, because the spectrum analyzers are set up to show from typically 20hz and up.

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