EQ3 changes audio even when set to Unity Gain

[c7n]

OK so, within the last 6 months I have started using EQ3 a lot just because someone showed me it works as a highpass / lowpass filter with very low cpu usage. You can set the filter frequency, but you don't have control over the filter "Q". That's perfectly fine when all you want to do is remove lows and or highs in your various tracks to make room for other elements.

However this weekend I was in the studio with a producer I haven't collaborated with before, and he refused to use EQ3 at all initially and then showed me that EQ3 even set at unity gain and with no frequency bands turned off, will change the sound.

He used several different midrange sounds and each one was notably effected by simply dropping an EQ3 on the channel, you can reproduce this by simply dropping an EQ3 on a track then turning it on/off to a:b the sound.

Is there another "CPU Light" way to remove unwanted high / low noise which doesn't involve EQ8 or Auto Filter... each of those seems to use more cpu. Would I be better off simply dealing with the CPU hit incurred by using EQ8 if I wanted to minimize unwanted changes to the audio?

[mr.adl]

EQ3 changes the sound, it´s even stated in the manual. It´s not supposed to be "clean".

[Khazul]

Well spotted!