[RRod]

  144 dB and 192 dB of dynamic-range, respectively.  So yeah, pretty much what you said

 

Let's keep in mind, guys, that the vast majority of music has no more than 20dB of dynamic range.
 
That being said, bit-depth determines more than just the dynamic range of music.  Ever tried listening to an 8-bit music file?  If so, you should have been able to perceive that just because 8-bit can reproduce almost 50dB of dynamic range (more than enough for any and all music) does not mean it won't sound like crap.  That's because it also determines thingss like the level of the noise-floor relative to the main signal, amplitude of harmonic distortion, etc.

 
I have a few metal tracks that I can take down to 8bit with no issues, but like you said it doesn't take much dynamism at all to get those 8-bit artifacts to pop through. It's still fun to look at DR/loudness range and try to predict if a track will work that low

 

[goodyfresh]

   
I have a few metal tracks that I can take down to 8bit with no issues, but like you said it doesn't take much dynamism at all to get those 8-bit artifacts to pop through. It's still fun to look at DR/loudness range and try to predict if a track will work that low

Glad to know I'm not the only guy who's nerdy enough to spend freetime playing around with a converter (dBpoweramp in my case), converting things down to 8-bit and then seeing what I can and what I can't hear a difference on

 
So seriously though.  24-bit and 32-bit.  Over 140 and 190 dB of dynamic-range, REALLY?  As you said, fully-utilizing that wouldn't just be stupid, it would be physically dangerous, and in the case of the over 190dB range for 32-bit, actually DEADLY.  As in, sound on that level would literally be the same thing as (the sound from) shockwave from a fricking nuke going off in your face, it would reduce human flesh, blood, and bone to an indeterminable pile of mush, lmao.  It wouldn't be the same as experiencing the shockwave itself, but would be like the sound from it, and the effect ont he human body would pretty much be the same, i.e. it'd get ripped to shreds.
 
http://www.gcaudio.com/resources/howtos/loudness.html
 
"140dB--Loudest sound recommended for exposure WITH hearing-protection."
"180dB--Death of hearing tissue."
"194dB--LOUDEST SOUND POSSIBLE!"
 
Loudest sound possible means just that. . .sound at that level would create waves with such a large amplitude that their troughs would become actual VACUUM, in the atmosphere at average pressure at sea-level here on earth.  Any "sound" beyond 194dB in our atmosphere at sea-level would no longer actually be a soundwave, but rather an actual shockwave, in terms of the physics of what would be happening.  So that yes, sound in the range of 190 to 194dB would have the same general effect on living tissue as the shockwave from a large explosion.  Meaning that 32-bits of dynamic range could literally reduce a human being to nothing more than little teeny bits and pieces.  Lol.

 

[KeithEmo]

  Glad to know I'm not the only guy who's nerdy enough to spend freetime playing around with a converter (dBpoweramp in my case), converting things down to 8-bit and then seeing what I can and what I can't hear a difference on

 
So seriously though.  24-bit and 32-bit.  Over 140 and 190 dB of dynamic-range, REALLY?  As you said, fully-utilizing that wouldn't just be stupid, it would be physically dangerous, and in the case of the over 190dB range for 32-bit, actually DEADLY.  As in, sound on that level would literally be the same thing as (the sound from) shockwave from a fricking nuke going off in your face, it would reduce human flesh, blood, and bone to an indeterminable pile of mush, lmao.  It wouldn't be the same as experiencing the shockwave itself, but would be like the sound from it, and the effect ont he human body would pretty much be the same, i.e. it'd get ripped to shreds.
 
http://www.gcaudio.com/resources/howtos/loudness.html
 
"140dB--Loudest sound recommended for exposure WITH hearing-protection."
"180dB--Death of hearing tissue."
"194dB--LOUDEST SOUND POSSIBLE!"
 
Loudest sound possible means just that. . .sound at that level would create waves with such a large amplitude that their troughs would become actual VACUUM, in the atmosphere at average pressure at sea-level here on earth.  Any "sound" beyond 194dB in our atmosphere at sea-level would no longer actually be a soundwave, but rather an actual shockwave, in terms of the physics of what would be happening.  So that yes, sound in the range of 190 to 194dB would have the same general effect on living tissue as the shockwave from a large explosion.  Meaning that 32-bits of dynamic range could literally reduce a human being to nothing more than little teeny bits and pieces.  Lol.

 
You're right - there is almost certainly no need for a dynamic range even as wide as that offered by 24 bits of depth in a recording that you're simply going to play as is. However, there are two "exceptions". First off, you need to differentiate between overall dynamic range and "local" dynamic range" (meaning dynamic range over a short time). In the case of listening to music, what that means is that we've all been assuming that you're going to turn the music on and let it play - so you're going set the level to where the loudest parts are comfortable (or, at least, non-lethal). However, not everyone listens to music that way all the time. So, for example, if you were to start listening to your favorite classical CD, with the level set so that the loudest parts were quite loud, the 16 bit CD audio would have plenty of dynamic range. But, if you manually turn it up 30 dB on the quietest spots "to hear them better", then the noise floor, or even digital artifacts, may be audible at that point - because, by raising the gain by 30 dB, you've also raised the noise floor by 30 dB (which makes the "effective S/N ratio" of your CD at that moment about 65 dB). So, if you're the kind of person who "turns it up to hear the details in the quiet spots", then using 24 bits, or even 32 bits, will prevent this from happening.
 
The other case is really the same thing - but when you're making a recording or editing it. If you've ever made your own recordings, then you know that you can't always predict exactly how loud things will be in advance. In a real studio setting, with time for sound checks, this isn't usually a huge problem. However, in less formal settings, it's usually very difficult to predict what's going to happen, and not at all uncommon to find yourself diving for a level control when things get loud (assuming you prefer to avoid limiters and compressors). Room acoustics change - a lot - when the audience arrives, and suddenly finding yourself recording from the fifth row instead of the twentieth can make a huge difference. You may also find that things get a lot louder when the commentator stops talking and the music starts.
 
If you've ever tried to record using a cassette deck, or a digital recorder that only supports 16 bit audio, then you know how difficult it can be to select a recording level low enough that you're positive you won't get any overload, yet high enough to avoid the noise floor of your recording equipment. Even though most micrphone preamps don't really have 96 dB of dynamic range anyway, between the various level controls on the mic preamp, the input pads on your equipment, and the unknowns of your source, having a recorder that operates at 24 bits makes it a lot easier to pick a level that's safely below even the remote possibility of overload, yet safely above the noise floor. (This is partly because you have more adjustment range to use, and partly because, even though portable recorders really don't have much more than 90 dB of "real" dynamic range, ones designated as 24 bit devices usually are quieter than 16 bit ones.)
 
The same is a lot more true during editing - where different tracks may be boosted or cut in level - sometimes drastically. With editing, you also have the issue that any noise or artifacts that are present may be "magnified" when you add tracks together, and many types of processing actually boost the audibility of certain types of artifacts, as well as introduce new artifacts and mathematical rounding errors of their own. If you're mixing multiple tracks, recorded at different levels, and applying different processing to each, it's not unusual to raise and lower the level many times, and over a very wide range, over the entire process. And it's pretty obvious what's going to happen to the noise floor if you take a drum recording, recorded at a relatively low level to begin with, and boost the treble by 15 dB to "sharpen it up a bit". (I'm sure you've heard otherwise good sounding commercial recordings where the background noise jumped in level when a certain instrument or performer joined the mix; and various types of dynamic processing are well know to introduce "breathing" if the noise floor is even slightly audible before you apply them.) Making sure that the noise floor is FAR below audibility provides a safety margin against this. This is why most audio editing software actually converts the audio to be edited to 32 bits, or even 64 bits, and operates on it  at that bit depth. 
 
This isn't entirely limited to "process editing" either. For example, if you play a two-channel recording in simulated surround using Dolby PLIIx, you may find that certain artifacts and types of noise are exaggerated - because the decoding process "pulls" those sounds to the rear channels and raises their level. This was a major problem in the latter days of SQ4 four channel - where the typical decoder would specifically "misidentify" background noise and "place" it in the rear channels at boosted and varying levels - the result was that what sounded like relatively innocuous tape hiss or record surface noise in the front channels might end up sounding like a very audible and annoying desert sand storm in the rear channels. And, in modern equipment, you may find that your room correction system has "eaten up" 10 or 12 dB of dynamic range by boosting the high frequencies to compensate by a slight high frequency droop in your speakers, or a little extra absorption in your listening room.

 

[RRod]

   
You're right - there is almost certainly no need for a dynamic range even as wide as that offered by 24 bits of depth in a recording that you're simply going to play as is. However, there are two "exceptions". First off, you need to differentiate between overall dynamic range and "local" dynamic range" (meaning dynamic range over a short time). In the case of listening to music, what that means is that we've all been assuming that you're going to turn the music on and let it play - so you're going set the level to where the loudest parts are comfortable (or, at least, non-lethal). However, not everyone listens to music that way all the time. So, for example, if you were to start listening to your favorite classical CD, with the level set so that the loudest parts were quite loud, the 16 bit CD audio would have plenty of dynamic range. But, if you manually turn it up 30 dB on the quietest spots "to hear them better", then the noise floor, or even digital artifacts, may be audible at that point - because, by raising the gain by 30 dB, you've also raised the noise floor by 30 dB (which makes the "effective S/N ratio" of your CD at that moment about 65 dB). So, if you're the kind of person who "turns it up to hear the details in the quiet spots", then using 24 bits, or even 32 bits, will prevent this from happening.

 
Wait, so now we're justifying 24-bits by an effect we can get from dynamic compression? I find that the only reason I turn up the volume to hear quiet parts is because they've fallen near my room noise, in which case the artifacts you talk about would have to punch through the same room noise.

 

[KeithEmo]

   
Wait, so now we're justifying 24-bits by an effect we can get from dynamic compression? I find that the only reason I turn up the volume to hear quiet parts is because they've fallen near my room noise, in which case the artifacts you talk about would have to punch through the same room noise.

 
For the sake of discussion, let's talk about a cassette, which might typically have a S/N ratio of 60 dB; and let's assume that the cassette is "well recorded", so the loudest sound on it really is recorded at 0 dB (actually an unrealistic situation for a cassette), and I'm listening to my tape at a nice comfortable level. Now, I happen to notice that there are very quiet voices in the background; those voices are at a level of -30 dB, which is only 30 dB above the noise floor on my cassette. Now, when the music stops, I crank the volume up 30 dB to make those voices loud enough to make out. And, at this point, with that 30 dB of extra gain, which boosts both the noise floor and the voices equally, my S/N is only 30 dB.
 
However, if that recording was on a CD, which has a S/N of about 96 dB, and the voices are at the same -30 dB level, they are still 66 dB above the lower noise floor of the CD  (because the voices are at the same level but the noise floor is much lower). And, when I boost the level by 30 dB so I can hear the voices clearly, at that point I will still have a much more listenable S/N of 65 dB. (But, at a S/N of 65 dB, the noise will still be audible. However, with the -140 dB S/N of a 24 bit file, it would not.)
 
The fact is that we humans actually CAN hear a dynamic range of somewhere around 90 dB or 100 dB - if you allow for some time lag. If I walk into a well-designed concert hall, before the crowd arrives, I might actually be able to drop a dime and hear it hit the floor; and, when the full orchestra comes in and starts to play, at the loudest parts they may well be 100 dB louder that the sound of that dime hitting the floor; and I can hear both. It may take a minute or two for my ears to adjust between hearing one and hearing the other, but they could certainly both be included on a recording.... or that recording could contain both crashing crescendos from the full orchestra, interspersed by tiny tinkle taps of a 3" silver hammer on a tiny bell, not to mention the assorted breathing, chair bumping, and sounds of fingers contacting strings common in live recordings. (I'm sitting here in a very quiet office right now, and I can hear my own breath, and the sound it makes if I rub two fingers together a foot in front of me. I'll leave it to you to calculate the dynamic range it would take to accurately record both the sound of my fingers rubbing together and the slamming of an office door.) 
 
It also so happen that we humans have evolved to be much more sensitive to certain sounds than others. For example, I personally wouldn't know if a cello sounded "perfect" or "a little bit off", but, like most of us, I am quite sensitive to the way human voice, and even breathing, sound - so I notice it if the intake of breath between words in a song sounds wrong. Likewise, many people are very sensitive to the low level sounds that make up "room ambiance", which are what allow us to recognize different rooms, or to hear with our eyes closed whether there are two people or a half dozen in our living room. Different people vary widely in terms of how sensitive they are to this sort of thing - which is one reason why I would "prefer to be safe than sorry" when it comes to accurately recording and reproducing "acoustic information". (I haven't heard very many recordings of a cymbal where I honestly couldn't tell with my eyes closed whether I was listening to a recording or a real cymbal - there in the room with me.... try it some time. To me this means that obviously something is still not quite prefect in the process.)     

 

[goodyfresh]

   
Wait, so now we're justifying 24-bits by an effect we can get from dynamic compression? I find that the only reason I turn up the volume to hear quiet parts is because they've fallen near my room noise, in which case the artifacts you talk about would have to punch through the same room noise.

Dynamic compression is absolute crap and I hate it   Haha.

 

[RRod]

   
For the sake of discussion, let's talk about a cassette, which might typically have a S/N ratio of 60 dB; and let's assume that the cassette is "well recorded", so the loudest sound on it really is recorded at 0 dB (actually an unrealistic situation for a cassette), and I'm listening to my tape at a nice comfortable level. Now, I happen to notice that there are very quiet voices in the background; those voices are at a level of -30 dB, which is only 30 dB above the noise floor on my cassette. Now, when the music stops, I crank the volume up 30 dB to make those voices loud enough to make out. And, at this point, with that 30 dB of extra gain, which boosts both the noise floor and the voices equally, my S/N is only 30 dB.
 
However, if that recording was on a CD, which has a S/N of about 96 dB, and the voices are at the same -30 dB level, they are still 66 dB above the lower noise floor of the CD  (because the voices are at the same level but the noise floor is much lower). And, when I boost the level by 30 dB so I can hear the voices clearly, at that point I will still have a much more listenable S/N of 65 dB. (But, at a S/N of 65 dB, the noise will still be audible. However, with the -140 dB S/N of a 24 bit file, it would not.)
 
The fact is that we humans actually CAN hear a dynamic range of somewhere around 90 dB or 100 dB - if you allow for some time lag. If I walk into a well-designed concert hall, before the crowd arrives, I might actually be able to drop a dime and hear it hit the floor; and, when the full orchestra comes in and starts to play, at the loudest parts they may well be 100 dB louder that the sound of that dime hitting the floor; and I can hear both. It may take a minute or two for my ears to adjust between hearing one and hearing the other, but they could certainly both be included on a recording.... or that recording could contain both crashing crescendos from the full orchestra, interspersed by tiny tinkle taps of a 3" silver hammer on a tiny bell, not to mention the assorted breathing, chair bumping, and sounds of fingers contacting strings common in live recordings. (I'm sitting here in a very quiet office right now, and I can hear my own breath, and the sound it makes if I rub two fingers together a foot in front of me. I'll leave it to you to calculate the dynamic range it would take to accurately record both the sound of my fingers rubbing together and the slamming of an office door.) 
 
It also so happen that we humans have evolved to be much more sensitive to certain sounds than others. For example, I personally wouldn't know if a cello sounded "perfect" or "a little bit off", but, like most of us, I am quite sensitive to the way human voice, and even breathing, sound - so I notice it if the intake of breath between words in a song sounds wrong. Likewise, many people are very sensitive to the low level sounds that make up "room ambiance", which are what allow us to recognize different rooms, or to hear with our eyes closed whether there are two people or a half dozen in our living room. Different people vary widely in terms of how sensitive they are to this sort of thing - which is one reason why I would "prefer to be safe than sorry" when it comes to accurately recording and reproducing "acoustic information". (I haven't heard very many recordings of a cymbal where I honestly couldn't tell with my eyes closed whether I was listening to a recording or a real cymbal - there in the room with me.... try it some time. To me this means that obviously something is still not quite prefect in the process.)     

 
Yes I get what you meant about hearing noise; I was pointing out realities of listening to music in actual normal environments. Going from fingers rubbing to a door slamming indeed takes a lot of dynamic range, but you are assuming that we actually hear the door slamming in a perfect way, when we in fact have mechanisms to protect us from sudden loud sounds (so how loud are we actually hearing the door slam)?
 
Still it remains that listening to a recording by pumping up the volume at certain spots isn't how we listen to actual live music, where you just have to take what you are given. And there's the issue of timbre as well: a cello playing piano but with the volume cranked up does not sound like a cello playing forte with the volume at actually listening levels. So I don't really take to arguments about noise that require we "break the rules", as it were. I have no doubt many "passed" ABX tests online dealing with dynamism have been obtained by jacking up the volume.
 
I was just listening to an album that is one of the more dynamic (high DR and loudness range) in my collection, and indeed if I jack up the very quietest parts I can hear noise. But when O Fortuna comes blaring back in I'm reaching for the volume, and that's in my quiet back room with sealed cans on. So really, how much more range do you want?
 
The cymbal example seems to be leaping a bit from dynamic range to just sound in general. Many recordings will have the drums/cymbals manipulated separately from the rest of the instruments, which to me is probably a bigger culprit in why they might sound "off". But that's not a sample/bit spec issue.

 

[RRod]

  Dynamic compression is absolute crap and I hate it   Haha.

 
If done moderately it's quite useful, especially when you have a toddler running around who takes quite a few dB of dynamic range from the room

 

[goodyfresh]

   
If done moderately it's quite useful, especially when you have a toddler running around who takes quite a few dB of dynamic range from the room

OH well you didn't mention the part about the toddler before!  That changes EVERYTHING   Haha.

 

[KeithEmo]

   
Yes I get what you meant about hearing noise; I was pointing out realities of listening to music in actual normal environments. Going from fingers rubbing to a door slamming indeed takes a lot of dynamic range, but you are assuming that we actually hear the door slamming in a perfect way, when we in fact have mechanisms to protect us from sudden loud sounds (so how loud are we actually hearing the door slam)?
 
Still it remains that listening to a recording by pumping up the volume at certain spots isn't how we listen to actual live music, where you just have to take what you are given. And there's the issue of timbre as well: a cello playing piano but with the volume cranked up does not sound like a cello playing forte with the volume at actually listening levels. So I don't really take to arguments about noise that require we "break the rules", as it were. I have no doubt many "passed" ABX tests online dealing with dynamism have been obtained by jacking up the volume.
 
I was just listening to an album that is one of the more dynamic (high DR and loudness range) in my collection, and indeed if I jack up the very quietest parts I can hear noise. But when O Fortuna comes blaring back in I'm reaching for the volume, and that's in my quiet back room with sealed cans on. So really, how much more range do you want?
 
The cymbal example seems to be leaping a bit from dynamic range to just sound in general. Many recordings will have the drums/cymbals manipulated separately from the rest of the instruments, which to me is probably a bigger culprit in why they might sound "off". But that's not a sample/bit spec issue.

 
I guess that all depends on what you expect from a recording.
 
If I actually had "an all access pass" to a concert, I really might wander into the venue while it was still empty, sit down, and hear the sounds from the air conditioning system, and the scuff of the musicians' shoes as they sat down, and the rustle of papers being arranged on the music stands. At this point the "gain" of my ears would be at it maximum sensitivity - and at that moment I could probably hear that tiny sound made by my fingers rubbing together. Then, as the music started, my ears themselves would automatically reduce their gain so the loud parts weren't painful - at which point I wouldn't be able to hear my own breathing, or my fingers rubbing together. (I would be able to experience that huge dynamic range because of the automatic level control built into my ears.) However, if I had my recorder turned on from the moment I walked in, and I wanted to actually record and reproduce that entire experience, then my recorder and my playback system would in fact need to be able to reproduce that entire dynamic range as well.
 
To look at it another way, the 0 dB to 140 dB SPL scale is specified as being the range from the quietest sound a human being can hear to the threshold of pain, so, arguably, in order to properly reproduce "every sound that a human can hear at the proper level", a recording (and the playback system that goes with it) really should be able to cover that range. And, if it doesn't, then there is room for improvement. In fact, as with most design criteria, I would prefer a safety margin, so my recording and playback system should have at least a little bit more range than that. Cymbals are difficult to reproduce for a number of reasons, one of which is that they have a very wide dynamic range (the initial burst of energy when the drumstick hits the cymbal is massively powerful). Very few recording and reproduction chains can reproduce this successfully, so virtually every recording has at least some limiting and compression applied to the cymbal tracks, and the same holds true for the sharper drums like snare drums. (It also seems difficult to reproduce wire brush cymbals without their sound "blurring" in such a way that they sound like the simple burst of white noise produced by a steam valve, and I do hear significant differences in how different DACs reproduce them with some speakers - however, since I have one or two very good 16/44k recordings which seem to reproduce them perfectly, it obviously doesn't have anything to do with extended frequency response.) 

 

[RRod]

   
I guess that all depends on what you expect from a recording.
 
If I actually had "an all access pass" to a concert, I really might wander into the venue while it was still empty, sit down, and hear the sounds from the air conditioning system, and the scuff of the musicians' shoes as they sat down, and the rustle of papers being arranged on the music stands. At this point the "gain" of my ears would be at it maximum sensitivity - and at that moment I could probably hear that tiny sound made by my fingers rubbing together. Then, as the music started, my ears themselves would automatically reduce their gain so the loud parts weren't painful - at which point I wouldn't be able to hear my own breathing, or my fingers rubbing together. (I would be able to experience that huge dynamic range because of the automatic level control built into my ears.) However, if I had my recorder turned on from the moment I walked in, and I wanted to actually record and reproduce that entire experience, then my recorder and my playback system would in fact need to be able to reproduce that entire dynamic range as well.
 
To look at it another way, the 0 dB to 140 dB SPL scale is specified as being the range from the quietest sound a human being can hear to the threshold of pain, so, arguably, in order to properly reproduce "every sound that a human can hear at the proper level", a recording (and the playback system that goes with it) really should be able to cover that range. And, if it doesn't, then there is room for improvement. In fact, as with most design criteria, I would prefer a safety margin, so my recording and playback system should have at least a little bit more range than that. Cymbals are difficult to reproduce for a number of reasons, one of which is that they have a very wide dynamic range (the initial burst of energy when the drumstick hits the cymbal is massively powerful). Very few recording and reproduction chains can reproduce this successfully, so virtually every recording has at least some limiting and compression applied to the cymbal tracks, and the same holds true for the sharper drums like snare drums. (It also seems difficult to reproduce wire brush cymbals without their sound "blurring" in such a way that they sound like the simple burst of white noise produced by a steam valve, and I do hear significant differences in how different DACs reproduce them with some speakers - however, since I have one or two very good 16/44k recordings which seem to reproduce them perfectly, it obviously doesn't have anything to do with extended frequency response.) 

 
We need to decide if we're talking music or the gamut of hearing; I don't think anyone wants their music to have a 140dB dynamic range. I mean really, imagine surfing a 24-bit audio internet with cans that could deliver 24-bits sitting on your ears and tell me you actually want this. Besides, if I recorded my whole day there's no way I'd need 140dB for it. Even if I went to a metal concert tonight, I wouldn't need it, since I'm never in an environment that's much quieter than a library.
 
Wanting a safety margin is of course sensible, and hence why you won't see much contention on here for recording at 24bit. But saying it's necessary for delivery isn't on as solid ground, especially with noise-shaped dithering out there.

 

[KeithEmo]

   
We need to decide if we're talking music or the gamut of hearing; I don't think anyone wants their music to have a 140dB dynamic range. I mean really, imagine surfing a 24-bit audio internet with cans that could deliver 24-bits sitting on your ears and tell me you actually want this. Besides, if I recorded my whole day there's no way I'd need 140dB for it. Even if I went to a metal concert tonight, I wouldn't need it, since I'm never in an environment that's much quieter than a library.
 
Wanting a safety margin is of course sensible, and hence why you won't see much contention on here for recording at 24bit. But saying it's necessary for delivery isn't on as solid ground, especially with noise-shaped dithering out there.

 
I agree - I don't think  anything past 16 bits is NECESSARY for most people, in most situations, either.... by which I mean specifically that regular music, well recorded and properly mastered, can almost certainly sound good enough when recorded at 16 bits that there would be no audible difference by using 24 bits instead.
 
I guess the difference is that I'm inclined to see safety margin as a necessity in and of itself. (If you had asked me, as an engineer, to design a system to reliably record a certain range of frequencies and a certain dynamic range, I would absolutely have set parameters somewhere around 50% OUTSIDE the required range - and not touching it. In other words, if you had requested a frequency range of what humans can hear, and a dynamic rage of 90+ dB, I probably would have chosen 24/96k as "being able to deliver that with a reasonable safety margin".)
 
I can understand how that didn't happen with CDs - because the constraints of the available technology barely allowed the inventors to squeeze an hour of music onto the requisite sized disc with a bandwidth of 20 Hz to 20 kHz. However, now that we have virtually unlimited bandwidth and dynamic range available, it seems a shame not to add a reasonable safety margin - just in case - simply to reduce costs by a (very) few cents. (It's sort of the same reason why, if I needed a two quarts of water, I'd probably fetch a full gallon jug, and then pour out the excess, rather than risk getting exactly two quarts and coming up short.)

 

[RRod]

   
I agree - I don't think  anything past 16 bits is NECESSARY for most people, in most situations, either.... by which I mean specifically that regular music, well recorded and properly mastered, can almost certainly sound good enough when recorded at 16 bits that there would be no audible difference by using 24 bits instead.
 
I guess the difference is that I'm inclined to see safety margin as a necessity in and of itself. (If you had asked me, as an engineer, to design a system to reliably record a certain range of frequencies and a certain dynamic range, I would absolutely have set parameters somewhere around 50% OUTSIDE the required range - and not touching it. In other words, if you had requested a frequency range of what humans can hear, and a dynamic rage of 90+ dB, I probably would have chosen 24/96k as "being able to deliver that with a reasonable safety margin".)
 
I can understand how that didn't happen with CDs - because the constraints of the available technology barely allowed the inventors to squeeze an hour of music onto the requisite sized disc with a bandwidth of 20 Hz to 20 kHz. However, now that we have virtually unlimited bandwidth and dynamic range available, it seems a shame not to add a reasonable safety margin - just in case - simply to reduce costs by a (very) few cents. (It's sort of the same reason why, if I needed a two quarts of water, I'd probably fetch a full gallon jug, and then pour out the excess, rather than risk getting exactly two quarts and coming up short.)

 
The safety margin has existed on the recording side for many years now (when did the first 20-bit recordings start to happen?) And on the delivery side you have things like dithering and oversampling that have also been around for a while to help make things easier. And all of this was still not using up all that 16-bits could offer on the playback side, because having that much dynamic range in a recording is pretty much super annoying.
 
Here's a screenshot of one of my more dynamic albums, recorded in 1985:

 
I did the following:
.found the softest section
.gained it down 15dB without dither
.gained it back and listened to the difference; nothing there to hear
.put this back-to-back with the loudest section of the piece
 
Here's the result. I literally have to max out my volume to get that quiet section where I want it (in isolation), and there's no way I want the loud section to play at that level. The only option I have to possibly enjoy this would be to move to a quieter room, and I'm already at 37dBA in here. So yes, maybe in a 20dB room I might detect some differences from the gain, but that is not where about 99.999% of people listen to music (my out-of-the-air figure
 
And this is Mahler, fergawdssake. For much more normally dynamicked music, 16bits is already a safety margin. Now if recording engineers want even more safety for tracks like above, great. And if they don't want to bother with making 16-bit masters then fine. But don't charge me any more for it, which is really the brass tacks here.

 

[nick_charles]

 
And this is Mahler, fergawdssake. For much more normally dynamicked music, 16bits is already a safety margin. Now if recording engineers want even more safety for tracks like above, great. And if they don't want to bother with making 16-bit masters then fine. But don't charge me any more for it, which is really the brass tacks here.

 
LOL - Mahler is my go to for dynamic range demonstrations - even Mahler does not go much above 60db DR (10 bits give or take...)

 

[RRod]

   
LOL - Mahler is my go to for dynamic range demonstrations - even Mahler does not go much above 60db DR (10 bits give or take...)

 
Yeah, -65 to -70dbFS is the best RMS I've seen in the stuff I have.