Is there really a difference in sound between lower sampling rates like 44.1 and 48 KHz and hi-res such as 88.2 and 96 KHz?
Yes there is but it’s not for the reason you might think. It’s not likely to be the difference in high frequencies that you’ll hear. The range of human hearing is 20 Hz to 20 KHz. A 44.1 KHz sample rate (the sample rate of audio CDs) does reduce the high frequencies a little bit above 18 KHz. Higher sample rates do preserve these ultra high frequencies. Even a 48 KHz sample rate can represent frequencies up to 20 KHz (the limit of human hearing). However the truth is that studies show most people over the age of 30 cannot hear anything above 17 KHz and this reduces further as you get older.
Yet people reliably report that high sample rates like 88.2 and 96 KHz sound better than 44.1 and 48 KHz. The reason for this, as the legendary mastering engineer Bob Katz explains, is in the way currently designed digital to audio converters (DACs) work. When converting from digital to analog for playback, it is very difficult and expensive to produce an undistorted signal with lower sample rates like 44.1 or 48 KHz. There are at present no commercially available systems that can reproduce these sample rates without distortion. However, once you are at a high sample rate like 88.2 or 96 KHz a good converter can produce a completely undistorted analog signal with ease. So the difference people are hearing, is not the high frequency content, but the fact that lower sample rates cause the converters to distort the analog signal. For the tech minded, this is due to ripples in the bandpass filter cased by restricted high pass bandwidth in lower sample rates. For more in formation and detail on this we recommend Bob Katz’s excellent book Mastering Audio: The Art and the Science 3rd edition.
There is another very important reason to record at either 88.2 or 96 KHz. Digital processing tools work much better at 88.2 and 96 KHz than they do at lower rates. This can have a big effect on the quality of the sound both during mixing and mastering.
Also the audiophile market has moved to hi-res audio. Hi-res music vendors require 88.2 and 96 KHz.
These days more and more music is being recorded at 88.2 or 96 kHz. There are various reasons for this. One important reason is that many audio plugins used in mixing cause aliasing (unpleasant digital distortion) at the lower sample rates of 44.1 or 48 kHz. However recording at 88.2 or 96 kHz will mean that this distortion does not occur. Some plugins oversample the audio to reduce or remove this distortion, but many do not (including many from the major vendors). This distortion accumulates with each plugin used so the results will vary a lot depending on how your album is mixed. However since recording at 88.2 or 96 kHz avoids this whole problem, it’s worth considering.
We can work at any bit depth or sample rate, so don’t despair if your music was recorded at lower rates.
The difference in sampling rates is a lot more subtle to the point where they may not be noticeable on all listening systems. Many people record at the lower rates of 44.1 or 48 KHz due to CPU restrictions of the mixing computer. Although these rates are fine, 88.2 or 96 KHz will sound slightly better on many playback systems, especially audiophile systems. If your target market might be audiophiles, 88.2 or 96 is recommended.
It’s not that these higher rates actually contain extra musical information, the issue is to do with the filters playback systems need to use to decode digital. Higher rates allow playback systems more room to work, and many will sound better as a result. Some people even record at 192 KHz, however there is some evidence that rates this high are actually less accurate due to the maths involved.
We feel that 88.2 or 96 KHz are a very safe bet, and this is what we recommend, unless your mixing computer can’t handle them. If you have recorded at 44.1 or 48 do not change to a higher sample rate. The difference between this and higher rates is small and will not make or break how good your music sounds.