Sample rate is one of those settings in your DAW that can be tricky to get your head around. It doesn’t help that there’s a lot of wildly varying information out there on the subject. I’m going to demystify sample rate, debunk some myths and tell you exactly which sample rate you should use for home recording.
What is Sample Rate?
When we record audio it starts off as an analog signal, whether that’s the signal coming from your guitar, or the signal that a microphone picks up when you sing into it – it’s all analog. Now, for your computer to be able to understand that audio signal it needs to convert it into a digital signal. Normally your audio interface will be performing this job.
During this process, snapshots (or samples) are taken of the audio. And those snapshots are taken so fast, that the audio can be represented in full on a digital system. The sample rate, is how many of those snapshots are taken every second. For example, the common sample rate of 44.1kHz, will take 44,100 snapshots of the audio every second.
How Sample Rate Affects Audio In Practice
But how does it actually affect the audio? The more samples the better, right? Well yes and no. It’s true that the more samples of the audio taken (so, the higher the sample rate), the smoother the resulting waveform will be, but once you’ve hit a certain number of samples per second, humans cannot tell the difference.
According to the Nyquist Theorem of sampling – a sample rate of double the audible frequency spectrum is enough to perfectly reproduce the original signal. The audible frequency spectrum is 20 Hz to 20,000 Hz at its absolute best (although in reality, most humans can’t accurately hear at the very top of that). Therefore, 44.1kHz (being over double that) is more than enough to accurately represent the audio.
Industry Standard Sample Rate
This is why 44.1kHz is the industry standard for CD audio. And if you’re wondering what that extra 4.1kHz is for, it’s because when the signal is converted, frequencies over the audible frequencies are filtered out with a low pass filter. That extra 4.1kHz gives the low pass filter some space so that it doesn’t affect the very top end of the audible frequencies.
Why do people use higher sampling rates then, like 48kHz, or 96kHz or higher? Some engineers claim that they can hear the difference, that the higher sample rates give a smoother or ‘warmer’ sound.
I’m not sure if this is the case for everyone who claims it, especially as a result of just the sample rate change, but there are so many other factors that could result in this experience.
- Their converters could do a better job…
- The specific plugins that they use may work better with audio of a sample rate
- The engineer might be a dog
- Or it could be the good old fashioned placebo effect
It’s very difficult to know as there are so many variables, outside of the science of the Nyquist Theorem. The issue is that when an engineer recommends a particular sample rate based on their personal experiences in their studios, you might find it doesn’t relate the same in your studio and to your ears.
Ultimately though, even the differences that some claim to hear are negligible at best, and the average listener isn’t going to notice any difference. Especially once the music has been converted to the industry standard 44.1 kHz and played back on a streaming service or sound system that further affects the sound.
Sample Rate vs. Frame Rate
I’ve seen a lot of engineers compare audio sample rate to video frame rate. I get that it makes it easier to understand the concept behind sample rate, but in reality, they are nothing alike. The perceivable difference between two standard video frame rates, for example 25 FPS (often used for TV), and 60 FPS (that many video games run at) is staggering. There’s a significant improvement in the experience to the vast majority of consumers – the smoothness, the responsiveness when playing a video game in a higher FPS, and so on.
This isn’t the case when comparing sample rates. 44.1kHz and above in theory perfectly represents the audio. That’s not the case with video with the frame rate standards we have today. It’s not a helpful comparison and it can be misleading.
Some suggest recording at 96kHz and above simply for future-proofing reasons. That perhaps in the future a higher sample rate will become standard and your classic recordings will become redundant. But these high sample rate files take up way more hard disk space and more CPU power, all just for a ‘just-in-case’ scenario. And upsampling exists. Think about it, those old records that were recorded to tape decades ago, have they been lost to the ages? No.
What Sample Rate Should You Use?
This is why for recording music or dialogue at home, I recommend recording at 44.1kHz.
If you’re recording for film or TV, you’ll need to use 48kHz simply because that’s the industry standard. And for sound designers who do a lot of pitch shifting and time stretching, they may need to go higher. But if you’re just recording music for CD and streaming, 44.1kHz is absolutely fine. It’s the sample rate needed to accurately represent the entire audible frequency spectrum. And in 99.9% of cases, no-one will notice the difference.
Ultimately it’s something that you don’t want to have to worry about. With a sample rate of 44.1kHz your system will run smoother, the files will take up less space and you won’t have to worry about any compatibility issues. The tiniest of recording and mixing decisions can affect your music far more than a higher sample rate would. So focus on the production itself.
One last point before I go, I’ve seen some engineers suggest that you should use higher sampling rates to attract clients to your studio. Now, if you’re someone who works with clients and one of them specifically requests a certain sample rate, or they send you audio in a certain sample rate to work on, then go right ahead and work in that sample rate if your system supports it. But the majority of clients aren’t likely to know or care – they just want a quality product. And advertising sample rates is redundant in my opinion. It’s not something that’s going to win you or lose you clients.
I hope this has been helpful to you. Is there anything that you’re still unsure about? Please let a comment below and I’d be happy to help!
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Happy to help, Declan!