As i was at full stop, while waiting for the Akula to move near me, i imagine the towed array was in fact falling to the sea floor, and so that's why it was making all those parasites.
But i was using the sphere array for that detection, and the AI crew has not been able to detect the Akula passing near (considering that i was at the port entrance and the water were shallow, i imagine the distance between my 688 and the Akula must have been very very small, i just hoped there would be no collision).
Moving to get the towed array in function, while being that near an Akula would have been suicide as i doubt the Akula sonar AI crew would have been as blind as mine, and i was forbidden to attack, but the Akula had no such orders
I believe the accelerated time may have been a part of that AI crew blindness problem, as it is possible the AI scripts calculations and loops may have "jumped" a bit in such case.
I will try without accelerating time when i will be in the port entrance again to see if it was indeed the problem.
Thanks for the brightness/gamma settings idea, i never thought of doing that, it should help.