44.1 kHz vs 48 kHz Okay, let me start by stating I do not believe there is an audible difference between the two that adults can hear. Children maybe, but not adults. Children may be able to hear a difference with audio that goes up towards 20 kHz tones because anti-aliasing filters are not perfect and have an impact on frequencies close to but below Nyquist. With 48 kHz Nyquist is 24 kHz and with 44.1 kHz Nyquist is 22.05 kHz so with respect to 20 kHz that some children can hear, a 48 kHz sample rate gives a little more headroom for the ADC anti-alias drop-off below Nyquist to only affect frequencies above 20 kHz. But for adults I don't think it matters. Secondly, for playback I believe the super high definition frequencies are a waste. Digital Signal Processing is science and a properly functioning DAC will produce perfect waves from data below Nyquist. In simplest terms, think of polynomials. Given any two sample points, if you know it is a line you can perfectly reproduce an analog version of the line. More won't allow you to produce a "better" line, you have enough information to make a perfect analog line. Any three sample points, if you know it is a parabola, you have enough data to make a perfect analog parabola. Or if you know it is a circle, a perfect analog circle. Digital waves are not lines or parabolas or circles but the point is you can take discrete sample and create perfect analog representations, and with digital signal processing, what we need to be able to make a perfect analog signal is a sample rate at least twice the highest frequency we wish to reproduce. With a little headroom for issues like imperfect anti-aliasing filters that remove the frequencies we don't want to reproduce. 96 kHz or 192 kHz sample rates have value in the mastering process but not for playback within our audible range. The superior sound of vinyl that many of us (myself included) enjoy is the result of artifacts from the medium, artifacts that are pleasing to our ear. They can now allegedly be reproduced in digital with filters, though I suspect the slight variances that happen during vinyl playback may be part of the magic of vinyl. With respect to 16 bit vs 24 bit audio, I do believe some people may physically be able to tell the difference but I'm guessing only with the volume turned up so loud that it would damage your ears and you wouldn't be able to tell the difference for long. At typical listening volumes, the noise floor of 16 bit is below what we can hear already. But back to the purpose of this thread, 44.1 kHz vs 48 kHz. There is not an audible difference in my opinion, but I believe that unless you are mastering an audio CD, digital audio should be mastered to 48 kHz for playback. Here's why. When the DSP in your computing device mixes audio, they need to be at the sample rate. Digital audio at a different sample rate has to be re-sampled. I don't know how many of you build your own PCs, I build my own even though it is more expensive because I like to pick goes into it. In the old days, when building a PC there was an audio cable that went from the CDROM to the sound card. The reason for this, in the old days computer sound cards could only process 48 kHz PCM data, so 44.1 kHz PCM data would have to be re-sampled and that would take processing power. So the CDROM drives had an audio cable feeding analog audio to the sound card for playback, avoiding the need for re-sampling. Nowadays, most sound cards can do 44.1 kHz and re-sampling doesn't tax the system as much, so that audio cable is not needed. But if your sound-card is set at 48 kHz, those 44.1 kHz audios are re-sampled every time they play. Many sound cards switch between the two. If nothing is playing, and a 44.1 kHz audio is played, then the sound card will operate at 44.1 kHz and not have to re-sample. If a 48 kHz audio is played, it will operate at 48 kHz and it does not have to re-sample. This usually works well, but switching sample rates it is operating at can be a source of problems if the drivers are buggy. The 44.1 kHz sample rate really was only ever used for Audio CD. It was also used for digital downloads because some people liked to burn audio CDs of their digitally purchased music, so 44.1 kHz meant no re-sampling was needed. People don't burn audio CDs nearly as much now, so I don't see a reason to keep using 44.1 kHz. Digital video is on the increase and digital video uses 48 kHz sample rate, I think digital audio should follow suit and use 48 kHz as well. If we phase out 44.1 kHz, sound-cards will pretty much only need to deal with one sample rate and switching between the two won't be needed. Occasionally re-sampling 44.1 on the fly would be required of a sound card set to only operate at 48 kHz but that is not difficult to do today. Buggy drivers that crash when a sound-card switches aren't an issue if it never switches. This is actually something I do when I rip a CD. I rip to a single file, and while I do archive that in flac as ripped, I also then re-sample to 48 kHz and after the re-sample, split the tracks. There isn't an audible difference, when I first started doing this, I did re-sample loop - Source CD -> 48 kHz -> 44.1 kHz -> 48 kHz etc. 100 times and I was not able to hear any differences between the final result and the the original 44.1 kHz. If doing it back and forth 100 times on my test loop (Struntz & Farah - Primal Magic) did not produce an audible difference, then doing it once isn't going to cause an audible difference on any music, even if some players re-sample back to 44.1 kHz (e.g. playing it on a smart phone). Interestingly, the developers of the Opus codec seem to have the same philosophy - 44.1 kHz is not a native sample rate for Opus, if you rip an audio CD to opus it will re-sample it to 48 kHz while encoding. So nutshell, it is my opinion it is time to phase 44.1 kHz out. Keep things simple for the sound-card, keep playback set to 48 kHz and re-sample the deprecated legacy sample rate when it is played. For new recordings, record to 48 kHz. For ripping CDs, the CD has to be 44.1 kHz on the CD but for lossy encoding, re-sample to 48 kHz either manually or by using a codec like Opus that does it for you. That's my opinion. Of course do what you want, it is just my opinion. In reality it probably is not a big deal, I'm famous for over-thinking things, but I like KISS and while re-sampling my CD rips may not appear KISS on the surface, keeping my sound-card at 48 kHz is KISS.