Music Technology 101: Sampling Rate and Bit Depth Explained

In this short video I will explain two widely used terms in music technology: sampling rate and bit depth. We'll also take a look at analog to digital conversion along the way.

Category:

Education

Tags:

• music
• technology
• sampling
• bit
• depth
• rate
• tutorial
• lesson
• explanation
• analog
• digital
• conversion
• sound
• card
• interface

[mikevanstaveren]

Thanks for the video! I have a question I hope you can answer it:

I dont really understand quantization, if you sample a audio track, at 44.1 Khz or higher, you have dots, like you showed in your video, if you connect the dots, you get pretty close to the original soundwave you drew on paper.

Why then is there such a thing a quantization? Why is it needed?

[MangoldProject]

@mikevanstaveren Your math paper analogy is good, with one caveat: think of the soundcard as the "grid" on the paper, not the paper itself. You DO play connect the dots, BUT not the original waveform's dots - first, when doing Analong->Digital, you're "warping" the input dots to the closest positions on the grid. When doing Digital->Analog, you're connecting the RECORDED (warped) dots. This "connect-the-dots" does NOT match the original waveform. It may be very close, but not exact.

[MangoldProject]

@MangoldProject As for why quantization is needed: it's a necessity. Ideally, we'd like to do away with it, but your computer has finite memory and processing capabilities, so it must store the voltage of the recorded waveform using a finite set of numbers. It's part of the price you pay for going digital (analog waveforms also have "effective" resolutions because of signal to noise, etc., but that's a different story.)

[mikevanstaveren]

@MangoldProject Thanks for your answer! So the more "Grid" your sound card has to "warp" dots the more accurate your sound is going to be! I just saw a nice analogy on you-tube, of a camera, the sample rate is the times the camera take's a picture, and the bit-depth, is how accurate the colours are i.r.l.

But what is kbps all about then? Is it how much info you stream from your device to the speakers?

And why is an mp3 128 kbps (and never xx bit and xx khz ) How are they connected?

[MangoldProject]

@mikevanstaveren kbps means "kilobits per second". It doesn't tell you anything specific about the sampling rate or bit depth. For example, an uncompressed 8-bit, 16kHz recording is (2^8 bits) * 16000 (per second) = 4096 kbps. Same goes for a 9-bit, 8kHz recording (=2^9*8000=4096 kbps). Note these numbers are much higher than the average 320 kbps MP3s use. That's because MP3s use lossy compression to reduce the number of kbps (without significantly degrading the quality).

[Fusionicon]

What are the equations involved ?

[MangoldProject]

@Fusionicon: I'm not sure what equations you're referring to. If you're talking about a particular statement made during the video, let me know at what time so I can review it.

[jabellae1]

I love your explanation... really you made me happy!

[manalexxxx]

ok i understand the denser the audio (8 bit---- 16 bit----- 24 bit) the better the sound quality. but the hertz? what is that again? so 16 bit -- 24 bit to 44.1 Khz -- 88.2 khz. how do these two work together? explain a little bit better pls.

[MrGolden94]

Thanks man, this helped me with my college essay alot! Love it :)

[domagoj19zg]

thnx man!!! 

[CallusDnb]

Excellent tutorial mate.

[jpelayo22]

thank you this video is being used in class as i Type this comment 

[rapagameover]

Thanks!!! this is really usefull

[childofconvienience]

Really really good you explained it perfectly so I could understand it without any troubles though I am not even a native speaker yet.

Oh and btw=) At the end you say "eye" instead of "ear"=)