I wanted to post a few words of warning about Bandcamp. It can be a great site for discovering new music and getting lossless downloads, but Bandcamp doesn't check the contents of what the artists provide for sale on their site. It is entirely caveat emptor.
Here's an example. Glass Hammer (a prog rock band from Chattanooga) recently started selling "96/24" versions of their albums on Bandcamp. The problem is, they're not 96/24 files. A basic FFT analysis shows that all these albums are brick-wall filtered at 22 kHz. No higher-frequency content in any of the tracks. Here's an example of one track from the Cor Cordium album:
I also ran these tracks through Bitter and Audio Diffmaker. Here's a 30 s wav file of the differences between the "hi-res" and CD version of the Perilous track "The Years Were Sped":
FYI, Bitter would show any use of the additional bit depth and Audio Diffmaker subtracts one time-aligned signal from the other, leaving the output as the mathematical difference between the two. This lets you easily hear/observe artifacts that might be missing from lower bit-rates, lower sampling rates, mixing/mastering differences, etc. The result of the above is total silence. Actually, there is some content there, but it's entirely inaudible to humans, since it contains nothing but insignificantly low-amplitude differences in a very narrow post-20 kHz roll-off. There are zero differences within the audible frequency range.
The upshot of all this was that Bandcamp refunded me my money and I deleted the files that were simply padding out my hard drive with zeros. Thank you Bandcamp. But in the meantime, neither Bandcamp nor Glass Hammer have pulled these albums. They're still available for sale today:
Steve Babb (the band's bass-player) responded to me as follows:
Bob Katz of Digital Domain created these files from our original 24 bit files and delivered them back to me exactly as they are labeled. Beyond that I don't know what to tell you. I've already received email from others who have purchased them telling me what a vast difference there was between the 24/44 and the 24/96 tracks.
Play the wav file I linked to above. Play it at the loudest volume you can on your most powerful amp and see if you can get a young child (somebody 60 years younger than Bob Katz) to listen too. There is zero chance of any human being hearing a difference, let alone a vast one. When pushed, Steve forwarded me a response from Bob Katz (their sound engineer). I quote verbatim:
Be sure to listen with your ears, not your eyes :-). But seriously, yes, it is true that these Glass Hammer files originated at single sample rate.
When I mastered them, prior to mastering, first I upsampled them to 32 bit float at 96 kHz, using the world's best sample rate converter: the Weiss Saracon. All my processors, analog and digital, perform better measurably and sonically at the higher sample rate. You can read my book, "Mastering Audio: The Art and the Science", for a technical explanation why the processing performs better at the double sample rate.
After mastering with both analog and digital processors at 96 kHz, I then went two more generations in order to produce the Glass Hammer standard rate CD: First I downsampled to 32-bit float/44.1 kHz. Then I dithered to 16 bit at 44.1 kHz. The result sounds smaller and a bit harsher than the original 96 kHz master.
In addition, most chip-based D to A converters perform better at the higher sample rate as well. This is also explained in my book.
So, by playing the 96 kHz/24 bit files you are getting the benefit of the warmer, wider, purer reproduction of my original masters. Granted, there is no high frequency material above the original Nyquist frequency of Glass Hammer's original files, but it is very debatable whether the ears can detect or get any benefit from those additional high frequencies. In fact, the debate continues on whether 96 kHz files sound better because of the increased bandwidth or the better filtering!
Bottom line: It sounds better, it is better. If Glass Hammer recorded and mixed their original files at 96 kHz, there might be additional information above 22.05 khz, or there might not, depending on the original instruments. The live drums and cymbals would exhibit additional harmonics. But whether you can hear them is debatable, although I am very convinced that recording and reproducing them at 96 kHz sample rate sounds better. We just are not sure why, and looking at an FFT is a pretty deceiving situation because our brains are very quickly fooled by my eyes. Until we can do a like-for-like blind test with single variables, that part of the mystery will remain. I can assure you that you are getting the benefit of listening to a greatly improved and earlier-generation master compared to the master used for the compact disc. Use your ears and report back and tell us if you agree on the sonics.
Lastly, I want to point out that Glass Hammer is selling these 96 k files at a reasonable price, largely because they did not originate at the 96 kHz rate, so that folks like you with FFT measuring gear won't complain, and will hopefully use your ears and also learn the provenance from the mastering engineer.
There's so much BS here I don't know where to start. You can basically drive a truck through each and every sentence he utters. For those of you that don't know Bob Katz, he's the sound engineer who's been railing against the "hi-res mafia" for not letting him sell up-sampled CD masters on HDTracks:
Kudos to folks like HDTracks for actually caring about the quality of what they sell. I can certainly see Bob's dissappointment though. Imagine you had the opportinity to take every recording ever made, quickly run it through an up-sampler and then sell it at twice the price of a regular CD; that would be faster and more efficient than printing your own money. Just one tiny problem here Bob - it's fraud.
Of course, there's a certain irony in selling fake hi-res files. If you knowingly purchase a jar of snakeoil and get home to find the jar empty - well, you probably don't have much legal recourse ;-) As I said at the top... caveat emptor.