When hi-quality mode is enabled, on the eq8 for example, 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.