To build on Chayro's post, I have an SPL Qure parametric equalizer which has the Qure processor. In addition to the normal 3 bands of parametric EQ the Qure processor messes with the signal's phase and adds a mid/hi boost which is intended to clarify vocal/instruments and reduce digital harshness. It also adds around 1-2 dB to the signal. I personally don't like the effect and never switch it into the signal path, but if is definitely noticeable.
I'm not saying that the SPL Qure is the same as the QOL device, but just pointing out that phase manipulation devices are fairly common and do have a sonic effect.
I'm not saying that the SPL Qure is the same as the QOL device, but just pointing out that phase manipulation devices are fairly common and do have a sonic effect.