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Nigel Redmon
United States
เข้าร่วมเมื่อ 22 มี.ค. 2013
Practical digital audio signal processing techniques explained.
How many bits can you hear?
Get an idea what level you can hear-how many bits. Give it a try with the announcing voice at typical listening levels, and again with the level turned up as loud as you would care to hear audio.
***Warning***-While this video test is good till you get to 16-bit, TH-cam audio encoding causes all sweeps after that to be the same level. So if you want to get to the really quiet levels, use the uncompressed audio at earlevel.com/main/2021/11/04/...you can even synchronize the audio to the video by opening it in an other window, and starting it about two seconds after the video, then muting the video's audio. Or, go to this blog post, which has the uncompressed audio in a player beneath this video, so you can play both in a single window: earlevel.com/main/2022/04/10/how-many-bits-can-you-hear-video/
The audio signal is designed to be easy to hear, and easy to differentiate from background noise. The signal itself is noise-free, so any noise in the system will be from your audio chain and room noise-in other words, normal listening conditions for you.
The signal is a digital square wave-"digital" because it was computed, not recorded, and transitions are on sample boundaries; the amplitude is at exact bit levels. It's twice the minimum possible signal for each bit level, because it swings between positive and negative bit values. The announcing voice is captured at the default Mac OS level, there is no compression or any other processing.
You can download the 24-bit audio file here, as well as get more information on the test:
earlevel.com/main/2021/11/04/a-listening-test
More detail on the test signal is available here:
earlevel.com/main/2013/03/24/perspective-on-dither
Please subscribe! I have major videos in the works, I need to know these are important to people, to justify the effort.
***Warning***-While this video test is good till you get to 16-bit, TH-cam audio encoding causes all sweeps after that to be the same level. So if you want to get to the really quiet levels, use the uncompressed audio at earlevel.com/main/2021/11/04/...you can even synchronize the audio to the video by opening it in an other window, and starting it about two seconds after the video, then muting the video's audio. Or, go to this blog post, which has the uncompressed audio in a player beneath this video, so you can play both in a single window: earlevel.com/main/2022/04/10/how-many-bits-can-you-hear-video/
The audio signal is designed to be easy to hear, and easy to differentiate from background noise. The signal itself is noise-free, so any noise in the system will be from your audio chain and room noise-in other words, normal listening conditions for you.
The signal is a digital square wave-"digital" because it was computed, not recorded, and transitions are on sample boundaries; the amplitude is at exact bit levels. It's twice the minimum possible signal for each bit level, because it swings between positive and negative bit values. The announcing voice is captured at the default Mac OS level, there is no compression or any other processing.
You can download the 24-bit audio file here, as well as get more information on the test:
earlevel.com/main/2021/11/04/a-listening-test
More detail on the test signal is available here:
earlevel.com/main/2013/03/24/perspective-on-dither
Please subscribe! I have major videos in the works, I need to know these are important to people, to justify the effort.
มุมมอง: 1 738
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All about amplitude modulation. This is background material for an upcoming video on sampling theory, and related articles on my website, earlevel.com. Please be sure to subscribe if you're interested in more videos. It's a lot of work, and I need to know I'm reaching people. Thanks!
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This video presents the “naked truth” on dither and truncation error, by stripping away the original signal of a musical clip and listening at different bit levels. I boost the error to a normalized audio volume for easy comparison of sound quality between different sample sizes, so your listening environment is not critical, but headphones will be a plus. Addition articles on dither, including...
Audio Dither Explained
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This video explains dithering in digital audio-what it is, and why we use it. Additional articles on dither, including examples, are available at earlevel.com: www.earlevel.com/main/category/digital-audio/dither-digital-audio/ Please visit EarLevel Engineering at earlevel.com for more tutorials on digital audio signal processing and sound synthesis.
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This video explains the classic synthesizer ADSR envelope generator, and its implementation in software. For a detailed, multipart tutorial including source code, please see www.earlevel.com/main/category/digital-audio/oscillators/envelope-generators/?orderby=date&order=ASC Please visit EarLevel Engineering at earlevel.com for more tutorials on digital audio signal processing and sound synthesis.
Wavetable Oscillator Basics
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This video demonstrates basic wavetable oscillator techniques. For a detailed, multipart tutorial including source code and examples, please see www.earlevel.com/main/category/digital-audio/oscillators/wavetable-oscillators/?orderby=date&order=ASC Please visit EarLevel Engineering at earlevel.com for more tutorials on digital audio signal processing and sound synthesis.
5 more hours Chris brown 😂
Nice job on this video, appreciate the extra work to make this easier to "see". You are a deep thinker I can tell. Keep on explaining!
Thank you! I appreciate the comments here, I'll work on doing more...
Thank you :)
It’s mind blowing that we can do more with less.
very helpful, thank you
As someone studying digital design this was insanely helpful. The example at 1:15 is nothing short of mind bending.
Thanks for letting me know-glad it as helpful to you!
Great explanation!
Thanks!
How to make square,triangle,saw waves is just add sine wave harmonics to the sine wave of the frequency you want your wavetable wave to be until you think the next harmonic is going to get past 20k hz
can i Like Twice?! Thank you
The best explanation of dither i've ever seen. Thank you so much!
Jennifer Lopez kiss
Great stuff, subbed
Awesome!!
this is another great explanation on your channel. thx
Thanks! Great explanation and great tool on your website.
Genius.
Even 8 years on this video is fantastic. I think an auditory example of the effect of dither would have been nice, but the excellent visual examples more than sufficed.
Thanks for saying. There are examples in my other video on dither: th-cam.com/video/KCyA6LlB3As/w-d-xo.html
Wow, great explanation!
Thank you very clear
Nigel, you are a humble yogi imparting wisdom amidst a vast ocean of misinformation. I love you ❤️
Thank you Sergio!
Keep generating content please 😍
Thank you, much appreciated
Good job
Thanks!
The catch here is that TH-cam encoding only leaves 16-bit audio, and 17-24-bit sweeps are rendered at the same level as 16-bit. Here's a workaround: Go to this blog post, which has the uncompressed audio in a player beneath this video, so you can play both in a single window: earlevel.com/main/2022/04/10/how-many-bits-can-you-hear-video/; as noted on the page, you just need to start the audio player two seconds into the video (when the green meter appears, as the sound starts), and mute the video's audio.
Just wanted to say I found your channel and love it
Thanks you!
Well yeah if you're toggling the least significant bit with a fixed full scale we're just losing 6db for each bit added to the resolution. You're just proving that 16 bit is enough to cover the human sensitivity range (from effectively complete silence to painful to hear)
I don't get it. What exactly is the signal here? A sine sweep? And why is it getting quieter with rising bit depth? Do you add the bits "on top" so that the volume effectively *_halves_* with every additional bit? I don't get it.
Click "show more", in the info above to get a little more detail, and a full explanation of the signal is at www.earlevel.com/main/2013/03/24/perspective-on-dither. The signal is a digital square wave, you can see the harmonics sweep down in the scrolling spectrogram. Two main reasons why I went with a digital square wave over sine sweeps: First, I want it to be easier to hear-I'm not trying to MAKE it difficult to hear, I want the listener to have a sense that this easy-to-hear signal becomes difficult to hear sooner than they might have thought. Second, a sine would have progressively worse signal-to-noise ratio, and require dithering, whereas the digital square sweep is alway exact at any bit depth. Thanks for being the first comment!
It shows you effectively how low the noise floor is, based off 0 dbfs. For example, 16-bit at -90.3 dBFS means you could set your speakers to play at 90.3 dB above the noise floor (in a very quiet room say 30 dB). This would mean the loudest parts would be 120.3 dB (painfully loud, most home audio or headphones won’t get close to this) with the noise floor effectively inaudible. The demo shows that anything above 16-bit for playback is kinda pointless however higher bit depths are very useful in mixing and mastering the final output. Gives you extra headroom before bringing the final output down to a more reasonable 16 bits per sample.
You remind me of _'Sweet Dither Bitter Jitter'_ paper which published many years ago. Wonderful video.
I couldn't find that paper, but thanks!
So useful. Thank you so much.
Bro thank you so much. This is an AMAZING explanation of dither, you are an amazing teacher. Turning such a complicated subject into something easy to understand is insanely difficult, yet you managed to do it. Thank you
Thank you so much, it helps to know-be sure to subscribe if you haven't so you don't miss my (long delayed, but I won't let another year go by) intuitive explanation of sampling theory...
thank u senor
nice explaination, I understand it immediately but why I can't access your website? I want to read more
Thanks! You should be able to reach the website at earlevel.com...it's probably because the link has "http", from back before the site was secure-only. I'll update it...
The best explanation in youtube !! Thanks!!!
Thanks, I appreciate you saying!
Super explained
Excellent. Best I've ever heard...
Thanks, David
Excellent explanation of dither. Thank you!
Appreciate it, Svein
so in in 24bit recording, rendering a 24 bit mix, I shouldn't need dither? and here is a question, if i used a 16bit sample in a 24bit recording, is their any steps reverse order here, to avoid issues
oh, self dither, so it seems to me dither is only for electronic or direct imput instrument recordings...
@@TEN-TIMES-HARDER It never hurts to dither 24-bit truncations, but it also won't even be heard. Now, some would say, "why not just said always dither, and make it easy on everyone?". The reason I make this point is because some feel that every external send in your DAW (out to a hardware reverb, compressor, tube EQ...) must be properly dithered or you project will be ruin. This is an unnecessary complication-besides the extra setup, there is the paranoia of making sure there are no further gain changes after the truncation, etc. And it's for something that impossible to hear. The truncation distortion of at 24 bits is far below the noise floor of any electronics possible (you can't escape Johnson noise and shot noise). If that weren't enough-for people who aren't electrical engineers, and doubt that fundamental truth-your ears can't hear it (people get fooled by reading that the ear has 140 dB of dynamic range-they forget that you will have permanent hearing damage if you exercise that extreme for even a few seconds on the loud end, and on the other end you're limited by the inherent noise in your room, noise of blood pumping through your veins, and the minimum energy required to deflect your eardrum (it's not massless). If that were enough, only the most artificial cases of computed music won't already have far more than enough of a noise floor to self-dither, as you say. The bottom line is that it's unhearable for several fundamental reasons.
Nice explanation. Although it's not centered around graphics I would add that pure randomness is the "naive" way when dithering an image. There are other less random algorithms that make the perceived image quality much better by placing the pixels in specific patterns. You briefly touched on this point for audio at the end.
Thanks for making this video!
Great
I still don't get it... Lol
Watch it one more time :-D
Short version: Limited resolution (sample size) results in a grid of possible values. The grid can possibly result in patterns in certain audio material that sound like the audio is distorted. By jiggling the grid a tiny bit, randomly, we don't get error patterns that line up with the audio signal-instead of a distorted signal, it sounds like the clean signal plus a tiny bit of hiss. Analogy: Close one eye and spread your fingers in front of your view, and read this. Your fingers will block some words. Jiggle your hand side to side, quickly, a small amount. Now you can read all the words, even though there is a little blur in front of them. The blur is better than the blocking.
Nice work !
Thank you so much! I was freaking out as I render 24 bit wav and FL Studio kinda suggests there's no need to dither at 24 bit but this clarification helped me loads as I've already rendered atleast 50 tracks without dither (24 bit)
Glad it helped, and thanks for letting me know!
Great content - your articles on earlevel.com are a reference I often point people to.
Thank you-I do appreciate it.
The visual analogy at 0:35 with pixels has blown my mind 🤯. I've been wondering what dithering is for about 10 years now, it always seemed something too difficult to understand for a regular musician, but thanks to you, I know what I'm doing now haha.
Great explanation!
Brilliant. Much respect, Nigel. Your way of explaining these three 'techniques' in light of the underlying principle makes for an excellent understanding of signals and systems. Your talent may be needed in schools and stuff. Thank you!!
Thanks!
Excellent teaching, Nigel. Clear as daylight, quick as the proverbial fox, and entertaining beyond compare. Me likes.
Much thanks, Morris
What a great visual demonstration of the concept in the beginning!
Hi Nigel, thank you for the video. Like the articles on earlevel.com I like how you use a strong theoretical approach as foundation and work your way up to the practical applications. Much appreciated and looking forward to more videos. Thanks for investing the time and energy to share knowledge. I recently became (re-)interested in DSP.
Appreciate the feedback!
Well explained. Thank you for this and I'm already looking forward to watch your next video
Thanks!