[…] I started asking myself, what is it we would be missing if these albums were downsampled to 88.2 and 96kHz?
Put another way, we could ask “Is there something musical about the highest octave in these 4x samplerate files?” This highest octave for 176.4kHz files would be audio containing 44kHz to 88kHz, and in 192kHz files from 48kHz to 96kHz.
Archimago, who does detailed analyses of digital audio files, finds that there is nothing in the higher end of very high resolution audio files. Nothing. While there is some audio content above 44.1KHz, there is nothing above 88.2 or 96 KHz. In fact, he finds that some very high resolution albums – including a few by Neil Young – are just up samples from lower resolution masters. In other words, a scam.
There’s an interesting comment by a reader:
Anyway, I have taken high sample rate files and done a steep filter removing everything below 20 khz. The reverse of the normal brickwall. That leaves only the ultrasonic material. I then slow it down to 25% of normal speed for playback. This is almost like upping your hearing to 80 khz. Even when you do this, there just isn’t much up there to hear. It isn’t loud at all. To think this, masked by the music, and well above your hearing will make a big difference becomes a clearly ludicrous idea at that point.
In short, this person deleted all the audio content that we can hear, to find if there was anything in the very high frequencies. While there was some audio, it’s too weak to hear. Archimago replied:
Yup. I’ve tried the same thing… High pass the stuff >20kHz, either slow it down or pitch shift down and have a listen. Most of the time noise and even if it’s correlated to the underlying music, usually extremely low amplitude and hard to imagine how the human ear can can even perceive or how most speakers would even accurately reproduce the sound without “supertweeters”!
I’m sure some folks will still comment on the idea that this stuff somehow adds to the “ambiance”.