New one : lowest steep , bands are 40, 100 Hz , difference is about 5-6 db and i see how the sinusoide is moving on the output scope. But even i use the "band coupling" ( i guess in this condition there is no difference) - the sinusoide still moving a little . But if in this condition i enable the lowest monitor - man the shaking is even bigger. That is why are my fears about the bass..
Flat tops are not helping too. Still unauthorized sounds added to the single 33 Hz freq.
In the Old MB bands are the default frequ`s and they are even closer - 43, 86 Hz , but no any moving/shaking of the signal.
Looks like this "shaking" is enough big problem that adds weird sound to the bass.
Something is causing a strange generation in the lowest band/bands . Like self-generating amplifier
P.S: I just tested with old MB without AGC , only the input amp + old MB - there is as little as possible shaking . Is the issue "amount of attenuating/decreasing" related too ?