Hi can someone explain me oversampling (plugins)
what is it?
why should we use it?
when/how should we use it?
does every plugins has this feature?
big thanks.

 

Lots to unpack with your questions!

The main reason oversampling is used is to reduce or eliminate aliasing. Aliasing occurs when frequencies above half the sampling rate are "mis-identified and get "reflected" back into the audio range - basically frequencies appear that are musically unrelated to the input signal, and that generally sounds bad!

Oversampling reduces or eliminates aliasing by increasing the sampling rate which means that the Nyquist frequency (half the sampling rate) also gets increased.

Of course, you don't get something for nothing. Oversampling also has downsides because the process involves filtering which can introduce problems with phase, transient response, etc.

Also, because you're adding more samples, the processing load increases accordingly.

Have a look here:

https://www.youtube.com/watch?v=qh-ybrG0qIg

 

I'm not an expert, but oversampling is used to reduce the aliasing effect: an issue which is caused in the digital world when calculated values go out of bounds. As a consequence, these values are reflected back in the audible range as harmonics. Especially in saturation and distortion plugins, aliasing can happen easily. But it could also happen during EQing or synth sound creation. The oversampling raises the audio kHz range, so that the values don't go anymore out of the range.

 

Oversampling is a digital audio processing technique that temporarily increases the sample rate of an audio signal within a plugin. For example, if your session is running at 44.1kHz, oversampling might process the signal at 88.2kHz or higher before downsampling it back to the original rate. This helps reduce unwanted artifacts like aliasing, which occurs when high-frequency content exceeds the Nyquist frequency (half the sample rate) and folds back into the audible range as distortion

Whats is Oversampling in under 3 minutes

 

Last edited: Apr 1, 2025

Oversampling increases the bandwidth of the signal and reduces unwanted artefacts (= side effects) that are created when digitally processing audio signals within a limited bandwidth. These unwanted side-effects are referred to as "aliasing" and tend to sound unpleasant.

Aliasing is produced when applying saturation / distortion in the digital domain (eg plugins in a DAW). Especially when digitally applying distortion, saturation (eg guitar amp plugins, analog emulation plugins with saturation) aliasing can occur. It's more likely to occur when you heavily distort signals with lots of high frequency content like hi-hats / cymbals or instruments playing at a higher octave. Its less likely to occur when you are saturating bass tones.

2 times oversampling a 44.1kHz sampling rate signal will increase the bandwidth to 88.2 khz

The downside of oversampling: it severely increases the CPU load and can introduce additional latency, which makes it difficult to use oversampled plugins in a live setting.

If you don't use tons of heavy distortion you have nothing to worry about. If you do, chances are your productions could benefit from oversampling.

 

The discoDSP - Discovery Pro VSTi is one of the few that offers oversampling and upsampling.

 

Since most people already gave the answers that matters, I'll just answer this:

If you are doing any process that adds a considerable amount of distortion (saturation, compression, limiting, clipping), it can be a good idea to enable it. My rule of thumb is pretty simple:

- Will enabling it make the plugin considerably more taxing on the system? If so, then I won't.
- Is the plugin one of the important processes that affect a wide range of sounds (like master bus processing)? Then yes.
- Can I hear a difference with it on? If not part of the second point, then I don't need it.
- Am I purposefully overdoing the effect? Then I might enable it.

People often get too worried about aliasing, even though they can't for sure say it's there without looking. So instead of worrying about something I can't hear, I just ignore it until I can hear it. If it happens, then I'll deal with it.

 

It kills your cpu performance without any audible effects, perfect for placebo listening A/B.

Mastering limiting is the only use.

 

I tend to agree and mostly skip it... But with the TBTech Vintage Suite I think I hear a relevant difference.

 

That "I think" you are saying is what scare me most!