[castleofargh]

imo much of this "under audible threshold" could be compared to high hertz/fps monitors... people said 30fps (24 actually) is enough but people are seeing still differences between 120vs240fps maybe even between 240 and higher fps
kinda wondering if there were a lot of studys suggesting "24 fps is all we need", probably to be honest, which would definitely show that "studys" dont state "facts" like you guys like to suggest

No, it could not. The only parallel is that all sensory systems have limits and constraints. It's a can of worms anyway, there is the FPS of the video and the refresh rate of the screen as 2 independent variables, plus fast refresh rates usually introduce non images between frames (the dumbest way being a gray frame to reduce ghosting). Some systems will extrapolate pictures between frames (effectively changing the FPS value, but also creating frames with images that didn't exist on the recorded video), while some systems will just repeat the same frame until it's time for the next one... Other variables might come into play as a result of all those differences in implementation, like luminosity and dynamic range as the refresh rate increases. Thinking we can draw conclusions about the impact of increased refresh rate (or increased FPS) based on how we happen to feel while experiencing 2 settings or 2 entirely different monitors, is just a case of ignoring all the variables until we think we can correlate what we want to correlate. TBH a lot of audio beliefs about audibility of certain variables rely on that very same logical tunnel vision and cherry-picking of what variable we want to believe is relevant to our experience.
And of course, eyes are not ears. ^_^

Jitter doesn't have one strict finite value for audibility because different types of jitter will stop being noticeable at different levels under different conditions, but of course there is a limit in time and amplitude for any signal and any listener within a given set of testing conditions. Thinking otherwise only makes someone wrong.
By nature, Jitter tends to be louder at higher frequency, so people look for that, but our hearing also loses sensitivity as we get into the treble. What we might barely notice at 2kHz, we're likely to need it to be 20dB louder at 15kHz to also barely notice it. Then there is all the masking caused by other signals, and the way our ears work, lower frequencies mask a wider range of nearby higher frequencies. Which of course is an issue in music if we try to use it to detect something. For those reasons and because some things did get tested properly, we do know for example that the threshold of hearing with music is a good deal worse than the very best testing conditions for the purpose of detecting jitter by ear. A trend that is found for a vast range of variables and hearing thresholds. Music is almost never the best solution to detect small amplitudes or small timings.
From all that work and from measurements of popular devices, it is fair to expect that jitter is rarely an issue that will be noticed. Of course, I'm sure we can find some "audiophile" products with antiquated design and horrible jitter numbers. Don't purchase those, problem solved.

You don't have to accept empty claims about something being inaudible (or audible), even less so if there is no clear statement of magnitude or any supporting evidence presented, but the notion of threshold is a fact. Nothing has infinite sensitivity (be it in amplitude or time), and certainly not human sensors.

 

[bigshot]

its said about so many things that its under the audible treshhold but still seem to matter for a lot of people

Salesmen were using fear of jitter as a selling point a few years ago. That's faded since all the studies show that jitter is far below the level of audibility, even cheap equipment performs as well as expensive components on that score.

while im not sure if i should agree about "digital audio doesnt matter at all"

I said jitter doesn't matter at all.

Honestly, there is absolutely no reason to worry about jitter. If you are interested, search this forum for the keyword jitter with the username nick_charles. He did a lot of research and testing back in the heyday of Sound Science. Dozens of interesting posts there to read. He went out of his way to buy the worst performing player ever manufactured when it comes to jitter specs, and he did a listening test with it. Take a guess what he found out.

 

[bigshot]

I work in animation. I can answer the frame rate question conclusively. The reason 24 frames per second was chosen wasn't because it's visually transparent. It isn't at all transparent. It's just barely capable of smoothly panning without stutters. It was chosen because of math. 24 frames divides in half three times. This makes it easier for editors and animators to plan action and cutting. Editors work in easily dividable numbers so they can keep track of frame counts. There are so called "magic numbers" for edit points, fade outs and ins and musical beats... 8x, 12x, 16x, 24x... They all divide multiple times. They might have chosen 32, which is also a magic number, but in the early days of film, it was expensive and they wanted to keep the footage count of film stock down as far as they could. If you think about it in terms of math, you can totally understand why film runs at 24 fps.

 

[71 dB]

I work in animation. I can answer the frame rate question conclusively. The reason 24 frames per second was chosen wasn't because it's visually transparent. It isn't at all transparent. It's just barely capable of smoothly panning without stutters. It was chosen because of math. 24 frames divides in half three times. This makes it easier for editors and animators to plan action and cutting. Editors work in easily dividable numbers so they can keep track of frame counts. There are so called "magic numbers" for edit points, fade outs and ins and musical beats... 8x, 12x, 16x, 24x... They all divide multiple times. They might have chosen 32, which is also a magic number, but in the early days of film, it was expensive and they wanted to keep the footage count of film stock down as far as they could. If you think about it in terms of math, you can totally understand why film runs at 24 fps.

The "speed" of human eyes depends on the amount to light. In dimmer light eyes work slower and vice versa. 24 frames per second is fast enough for movement transparency in low light conditions, but not enough in bring light conditions. The number 24 is a highly composite number with a prime factorization of 2*2*2*3 which makes it very usable for the reason you mention. 24 fps is also responsible for "cinematic look" which is lost when higher frame/interlaced field rates are used such as those common with video (50i and 60i).

 

[71 dB]

imo much of this "under audible threshold" could be compared to high hertz/fps monitors... people said 30fps (24 actually) is enough but people are seeing still differences between 120vs240fps maybe even between 240 and higher fps
kinda wondering if there were a lot of studys suggesting "24 fps is all we need", probably to be honest, which would definitely show that "studys" dont state "facts" like you guys like to suggest

People said 24 fps is enough to create the illusion on movement (which it is), but that doesn't mean you can't get a better illusion of movement using higher framerates. However, I believe above 100 fps the limits of human vision are met and I doubt anyone could see a difference between 240 fps and higher than that. Even between 120 fps and 240 fps must be really difficult.

 

[Davesrose]

The "speed" of human eyes depends on the amount to light. In dimmer light eyes work slower and vice versa. 24 frames per second is fast enough for movement transparency in low light conditions, but not enough in bring light conditions. The number 24 is a highly composite number with a prime factorization of 2*2*2*3 which makes it very usable for the reason you mention. 24 fps is also responsible for "cinematic look" which is lost when higher frame/interlaced field rates are used such as those common with video (50i and 60i).

24fps wasn't reached due to a scientific reason in regards to the viewer's vision. It was chosen because of it being a good compromise of the cost of film and seeing smooth motion (in any situation that the cinematographer is designing). There was also other implications as far of it being an easily divisible number (that also goes in the other direction of minimal camera shutter speed then being 1/48 as well as projector's shutter being 1/48). One main limitation with 24fps is what kind of movement the camera can perform. If it tilts or pans too quickly, then there will be a stutter. That's one of the arguments Peter Jackson has had with his preference of 48fps. But then the counter argument is that you can avoid stutter by having slower pacing.

Video standards like NTSC then set frame rate to 30fps (or PAL at 25fps). Now HD and UHD standards are 50/60fps. There has been different interpolation methods for converting source 24fps to 30 or 60 frames. Since native 50p/60p TVs are very prevalent now, the "soap opera effect" is something that's widely known. Cinema purists especially will turn off the interpolation (often called truemotion by TV brands).

 

[Davesrose]

Douglas Trumbull was one of the first directors to try to come up with a higher frame rate. He devised a 70mm film system running at 2.5x that of normal film (60fps). He was going to try to have VR scenes in the movie Brainscan to be in 60fps: but it proved to be problematic given the length of the movie (so most scenes were filmed in 35mm, and the VR scenes filmed in 70mm 24fps). 60fps 70mm wound up having some limited use with short segments in motion reality rides.

Interestingly, he did port it over to digital (where you are no longer limited to the physical problems of trying to deal with long film lengths):

 

[bigshot]

And of course this is all a tangent because film frame rates don’t relate to the audible transparency of digital audio at all.

 

[Davesrose]

[sarcasm]I don't know...when I watched Gemini Man in its native 60fps, the clarity in audio was greatly improved, and the height channels were noticeably active [/sarcasm]

 

[bigshot]

My soundstage runs at 120 fps. It’s like a veil has been lifted!

 

[Davesrose]

Ah, see, I spent $1200 on Audiquest GiveMeYourMoney HDMI cables. I find 120fps is too bright with them.

 

[bigshot]

Use a coax cable and you'll lose that HDMI "digital glare".

 

[Davesrose]

Good point....since I've got 7.1.4 speakers, I should now also invest thousands to convert my HDMI Atmos to a chain of stereo processors receiving coax...while I'm at it, wattage of speaker amp also must have to be related to frame rate too!

 

[gregorio]

imo IF things matter its probably jitter & noise on digital transports of any kind

Jitter was an audible problem in the early 1960’s when the first digital audio recorders were developed. By the early 1970’s tentative thresholds were already published in the public domain. By the 1990’s it was a non-issue, pretty much everything was magnitudes below the audible threshold, as ALREADY PROVEN! Also, any noise created by digital transports is eliminated, that’s the whole point of digital audio. So if there is audible noise, it’s either user error or something is broken/faulty.

i myself heared the effects on usb filters/cables ...

Which means nothing here. Maybe there was user error, maybe something was faulty/broken or maybe you didn’t hear any effects, you just experienced perception error/bias. Unless you eliminate these likelihoods, your claims are worthless to science and any discussion based on it.

imo much of this "under audible threshold" could be compared to high hertz/fps monitors...

Maybe they could be compared but to even start a comparison, those high hertz/fps monitors would need to be around a thousand times higher than the visual threshold. Know any monitors like that do you?

people said 30fps (24 actually) is enough

People also said the Earth is flat but this is the science discussion forum, so we don’t take what “people said” as fact. What is the actual threshold, what monitors exceed it by around 1,000 times and who has reliable evidence they can see it?

G