Ok, so I only just passed my science exams when aged 16 so my science knowledge is really shaky so bear that in mind; I've read so many posts on this forum and elsewhere to try to understand what I can expect to get sound quality wise from my audio equipment and from audio sources and wanted to check I'm on the right lines. I'm posting here though because it's a science forum and I trust scientific explanations over the waffle I have been trained to write as a flaky humanities graduate. If you can help with a few questions and check if my understanding is right then that would be really helpful.
1. Is it worth paying for 24 bit audio files with 48khz or higher, as opposed to CD quality tracks with 16 bit at 44khz?
part a: bits - my understanding: bits are related to volume levels. A 16 bit audio file can record up to 96db of dynamic range, so the difference between the quietest sound and the loudest sound on the CD is 96db. 96db is really loud. I would only benefit from having 24 bit audio if I was listening to music that was set at a volume where the loudest parts were more than 96db louder than the quieter parts. A whisper is about 30db in volume when I sit a couple of metres from the speakers. So, if my amp was set so that I could just hear a recorded whisper (let's say the sound engineer finished the CD with this 30db whisper as the quietest possible sound on the CD), and the loudest sound on the CD was 96db higher, that would be around 126db loud and that would not be a pleasurable experience. So I really don't need more than 16 bit audio?
part b: hertz - my understanding: hertz (in this context) refers to the number of times an analogue sound wave is sampled each second and converted into a digital value. So, if a musical performance was sampled only 30 times a second, it would be a 30hz recording and would be virtually impossible to listen to with pleasure because it would have missed so much of the performance. It is possible to capture an analogue sound signal perfectly if it is sampled twice the number of times per second as the sounds frequency expressed in hertz (from Nyquist’s theorem, ok - I’ve butchered it). So, if there’s a low note at 250Hz and it is sampled at 500Hz, that analogue signal can be captured digitally perfectly and later perfectly converted back into the analogue realm. So, because a CD is sampled at 44.1khz, it can send an accurate analogue signal to the amp providing the recording has frequencies of 22khz or less. As I’m an adult, I can’t hear any frequency above 22khz (and I can’t even hear that), so I don’t need to buy music that is sampled at a higher rate than 44.1khz?
2. How good does my DAC need to be so that I can’t hear the difference with a better DAC?
My understanding is really confused here. I’ve read on this forum (guess what, I can’t find where), that if a DAC has a Sinad of 96db then that should be transparent for a CD recording. So is it right to say that the Sinad measurement (which I get means ‘total harmonic distortion + noise’, but I don’t get what that actually means) means that any sound at a decibel level up to the Sinad value will be processed transparently, ie a DAC with 93db Sinad will process nearly all of an audio CD’s transparently, ie all but any information from 94db-96db?
3. Do I even need CD quality or is 320Kbs good enough?
My understanding: a CD quality track plays at a much higher bit rate (1,411 Kbps) than a 320Kbps track and this means more musical information is transferred each second the amplifier. So, theoretically CD could sound better than 320Kbps compressed files (which is entirely different to saying it sounds better in practice)? I’m aware of the huge arguments people have over this in practice, so I’m just focusing my question on in theory.
Any help is much appreciated.
1. Is it worth paying for 24 bit audio files with 48khz or higher, as opposed to CD quality tracks with 16 bit at 44khz?
part a: bits - my understanding: bits are related to volume levels. A 16 bit audio file can record up to 96db of dynamic range, so the difference between the quietest sound and the loudest sound on the CD is 96db. 96db is really loud. I would only benefit from having 24 bit audio if I was listening to music that was set at a volume where the loudest parts were more than 96db louder than the quieter parts. A whisper is about 30db in volume when I sit a couple of metres from the speakers. So, if my amp was set so that I could just hear a recorded whisper (let's say the sound engineer finished the CD with this 30db whisper as the quietest possible sound on the CD), and the loudest sound on the CD was 96db higher, that would be around 126db loud and that would not be a pleasurable experience. So I really don't need more than 16 bit audio?
part b: hertz - my understanding: hertz (in this context) refers to the number of times an analogue sound wave is sampled each second and converted into a digital value. So, if a musical performance was sampled only 30 times a second, it would be a 30hz recording and would be virtually impossible to listen to with pleasure because it would have missed so much of the performance. It is possible to capture an analogue sound signal perfectly if it is sampled twice the number of times per second as the sounds frequency expressed in hertz (from Nyquist’s theorem, ok - I’ve butchered it). So, if there’s a low note at 250Hz and it is sampled at 500Hz, that analogue signal can be captured digitally perfectly and later perfectly converted back into the analogue realm. So, because a CD is sampled at 44.1khz, it can send an accurate analogue signal to the amp providing the recording has frequencies of 22khz or less. As I’m an adult, I can’t hear any frequency above 22khz (and I can’t even hear that), so I don’t need to buy music that is sampled at a higher rate than 44.1khz?
2. How good does my DAC need to be so that I can’t hear the difference with a better DAC?
My understanding is really confused here. I’ve read on this forum (guess what, I can’t find where), that if a DAC has a Sinad of 96db then that should be transparent for a CD recording. So is it right to say that the Sinad measurement (which I get means ‘total harmonic distortion + noise’, but I don’t get what that actually means) means that any sound at a decibel level up to the Sinad value will be processed transparently, ie a DAC with 93db Sinad will process nearly all of an audio CD’s transparently, ie all but any information from 94db-96db?
3. Do I even need CD quality or is 320Kbs good enough?
My understanding: a CD quality track plays at a much higher bit rate (1,411 Kbps) than a 320Kbps track and this means more musical information is transferred each second the amplifier. So, theoretically CD could sound better than 320Kbps compressed files (which is entirely different to saying it sounds better in practice)? I’m aware of the huge arguments people have over this in practice, so I’m just focusing my question on in theory.
Any help is much appreciated.