Why Audio Formats Above 16-Bit/44.1 kHz Don't Matter
Musical records vary enormously in their recording and mixing quality. Albums like Daft Punk's Random Access Memories, most of Lady Gaga's pop work, Robin Thicke's Blurred Lines, and many others are simply masterfully recorded/mixed.
Obtaining an audiophile-quality 24-bit/192 kHz version of a poorly put-together track does nothing to make it sound better. As a matter of fact, in all of our blind tests, we couldn't tell the difference between 44.1 and 176.4 kHz, or 16- and 24-bit recordings. While those formats do have a place (namely, in the recording studio where the mixing headroom is a real advantage), they don't seem to add anything to consumer audio. Based on our experience, 16-bit and 44.1 kHz provides the best audio quality you're able to experience. Everything beyond that format tends to be a waste of drive capacity and, since the high-def recordings are more expensive, money as well.
Downsampling a 176.4 kHz track to 44.1 kHz using a high-quality resampler should prevent clipping and yield an output that you can't distinguish from the original. So, if you somehow find a 176.4 kHz recording in your hands and your hardware doesn't natively support it, don't worry. Resample it to 44.1 kHz and know that you're, in practice, not losing any of its fidelity.
Pretty much all modern DACs oversample inputs before the analog conversion (sometimes to a fixed rate [Benchmark converts everything to 211 kHz internally] and sometimes to a input-dependent rate, which is still usually pretty high). Besides the loss of audio frequencies above 22 kHz, which are inaudible, there should be very little difference between a native signal at 176.4 kHz converted to 211 kHz and a native signal at 44 kHz converted to 211 kHz.
The main advantage of 24-bit versus 16- is greater dynamic range (144 dB compared to 98), but that's practically irrelevant. Many of today's records succumb to the loudness war, where dynamic range is artificially compressed in the production stages. Michael Jackson's "Black or White", shown in the figure above, is a great example of this phenomenon. Even if the dynamic range of records wasn't becoming smaller, you'd be hard pressed to meaningfully experience a larger dynamic range in music. As a test, try some of the unscientific but directionally interesting tests on our conclusions page.
Monty at xiph.org has a separate and far more exhaustive discussion of this topic, and I encourage you to read it if you find the subject matter interesting. For our part, we're limiting ourselves to what we hear and understand, which tells us there is no difference between 16- and 24-bit, or 44.1 and 176.4 kHz.
DSD is a bit of a different story. SACDs are vanishingly rare. Any suggestions that the DSD64 format will pick up steam seems highly unlikely to us; even the academic world cannot decide if it is better than multi-bit PCM. The technicalities differentiating DSD and PCM are very complex, though high-quality DSD and PCM recordings shouldn't sound all that different. Both DSD64 and Red Book PCM are, in essence, hi-fi formats. Moreover, it's extraordinarily challenging to compare them in any objective way since DSD and PCM encodings are often obtained through separate masters. When they are not, the DSD encoding comes from a PCM master (what's the point, then?) or an eight-bit DSD called DSD-Wide, which has more similarities than differences from regular PCM. We just have to rely on subjective opinions on this one.
