Better Sound with Hi-Quality EQ8

The EQ8 has a Hi-Quality setting that is not enabled by default. We are able to find the Hi-Quality setting by right-clicking on the EQ8's title bar and selecting "Hi-Quality" from the contextual menu that appears. Once that has been done, the EQ8 will be in Hi-Quality mode, but what exactly does that mean?


This is a question that took me quite a bit of investigation to find the answer to, and one that requires more explanation than I intended for these particular videos, but this series is all about sharing esoteric knowledge (as it relates to Live of course) so that is what I will do right now.


When Hi-Quality mode is enabled on the EQ8, the audio being fed into the EQ is oversampled by a factor of 2 (meaning the sample rate of the audio is doubled. If your session's sample rate is 44.1kHz, enabling Hi-Quality will make the audio being fed into the EQ8 88.2kHz). Then the EQ changes are calculated at the doubled sample rate, and finally the audio as it leaves the EQ is undersampled by a factor of 2, or basically brought back to it's original sample rate.


Why does this happen? It all has something to do with what is referred to as the Nyquist Point. The Nyquist Point is one half of your sample rate, so if your session's sample rate is 44.1kHz, the Nyquist Point will be 22.05kHz, which is right at the upper limit of human hearing, and just beyond the furthest right edge of our EQ8's GUI. Any audio that produces a frequency higher than the Nyquist Point cannot be accurately reproduced digitally and will have aliasing or digital distortion as a result.


Because of this, the EQ8's frequency range was initially limited to 22kHz on the high end (when working on a session with a 44.1kHz sample rate). If your EQ is in normal mode (not Hi-Quality), and you create a notch on the 4th EQ point (reduce the gain all the way on the 4th point), start to increase the Frequency on that 4th point. You'll notice that as you get closer to the Nyquist Point (22kHz when working with a 44.1kHz sample rate), the curve of the EQ gets squashed so that the curve doesn't extend beyond 22kHz. Now, enable Hi-Quality mode and try the same thing. Notice how the EQ curve remains intact no matter how close you get to the Nyquist point.


So what does this mean in terms of practical application? Well, it means that you will probably only notice the effect of the Hi-Quality EQ8 if you're working on a session with a 44.1kHz sample rate, and the improvement will really only be noticeable on the higher frequency sounds effected by the Hi-Quality EQ8. As for specific instances for when you'd want to use the Hi-Quality setting and not, I think that is really for the individual to research a bit further, do a few A/B comparisons, and decide for themselves.