Bigshot,
How much do you think that one's personal preferences in music affect what aspects of sound reproduction they value the most? If I understand correctly, you are particularly fond of classical music, which, I think, tends to have much less content in the highest octave of human hearing, than, say, modern rock or metal, which feature much more percussion (notably the cymbal crashes).
The most important frequencies to the reproduction of music are the ones covered by Fletcher Munson. Next in importance are the mids below that. Then the bass and treble at the ends. Then the sub bass. Dead last is the top octave. It accounts for 10% of the range and far less than that of music.
That said, I definitely agree with this ranking of relative importance. For reference, I listen to music which varies from late baroque through modern classical to 60s and 70s classic rock and progressive rock through modern progressive rock, progressive metal, and hard rock. I don't listen to really any pop, hip-hop, country, or electronic anything. I don't know how those genre's might affect my priorities for sound reproduction. Maybe folks who favor pop, hip hop, and/or electronic dance type genre's might place bass quantity (and quality? maybe not?) higher up in their priorities? I'm not sure if there are electronic genre's that would use oodles of super high frequency synthesized sounds? I would find that painful, but the dog might rock out to that.
It's sort of funny (at least, I get a huge kick out of the fact) that the least important frequencies in music are the ones that make music files so stinking big. It's the highest octaves that take up all the disk space, just for the sake of satisfying Nyquist theorem for those frequencies. Every extra octave makes the file double in size.
Because this thread is lacking in sample calculations (at least to my satisfaction), let's do one:
If we assume that we can hear from 20Hz to 20kHz, then we can hear a 10 octave range. The octaves are (in Hz):
Code:
Octave: Start: End: Nyquist: 1 20 40 80 2 40 80 160 3 80 160 320 4 160 320 640 5 320 640 1280 6 640 1280 2560 7 1280 2560 5120 8 2560 5120 10240 9 5120 10240 20480 10 10240 20480 40960
Every time another octave needs to be captured in a recording, the resulting file size doubles. For the less technically inclined (do they every visit this forum?) we call a doubling in size with a unit increase "exponential growth", which is the the mathy way of saying something gets awfully expensive in a hurry. The theoretical minimum size of an uncompressed PCM file (per second) is the [Nyquist frequency] times [the bitdepth of the recording] times [the number of channels e.g., 2 for stereo]
.
If we ignored the top octave, and only recorded music up to 11025 Hz (i.e., sampled at 22.05 kHz), we would cut down the file size by 50%. If the music is band limited below 11kHz, then the recording with sampling rate of 22050 Hz would still have
exactly the same fidelity as a recording at 44100 Hz (or 88.2kHz, or 192 kHz, or 32 million THz, or whatever 30x super DSD is, etc.). This is throwing out 1 octave out of 10, i.e., the 10% of the range that bigshot mentioned above. Adding additional octaves beyond 20kHz extends the "musical range" by only a small fraction (
"musical range" is in quotes, because nobody can even hear those frequencies) at the expense of doubling the file size for each extra inaudible octave.
176.4 kHz audio increases the octave range of the recording by 20% over the 44.1kHz version,
all of it inaudible to humans, at the expense of increasing the file size to 400%. Your pet bats will thank you, though!
This is not a "glass is half full" vs "half empty" kind of thing. (well, one might say that 96kHz recordings are half full). For HiRes formats, this is a "glass is twice as big as they need to be (or four times, etc..)" kind of thing.
I recommend that we change the term "High Resolution audio" to "Highly Inefficient audio". I bet it will sell even better! You could shorten it to "High-In" audio. I wonder how this will go over in the other forums.
Cheers