Dear @deep_333 : I really appreciated your post and you can be sure that I will do all those.
Tou touched a critical issue in the subs correct integration to the room/speakers: PHASE that almost no one really speaks about when are talking of subs and " playing "/changing with comes with very high rewards that for me were unexpected to say the least.
By coincidence and before read your post last nigth I was " playing " with subs Phase making some changes ( btw, we modified the phase control in the HGS to go from only two phase positions to almost continuous changes. My HGS have several modifications made it by a friend and me: I changed the stock internal wiring from the drivers to the amp for pure silver KK cable, I by-passed all the internal fuses and changes passive and active parts in the input board and internal crossover circuit board. Even I change the damping foam by long hair virgen wool. The subs are at around 20 cm. from the floor and have a dead weigth of 30kg at the top plate. ) and I did it using CD MUSIC source as " Day after Tomorrow " that at its very first track comes with deep bass made/using synthesisers and I use other film soundtracks as Gladiator and the like and late in the nigth I gone to sleep but not totally satisfied.
So, I wake up early today and followed playing with phase changes this time doing with LPs mainly using the Telarc 1812 that has a wide kind of different bass frequency ranges and recorded with acoustic instruments and not synthesiser that’s different and after the changes with the phase finally I was truly satisfied with and learned the critical importance of PHASE about.
Thank’s for your knowledge advise. I’m just learning what it’s exiciting to me in that critical sub/speaker subject. Thank’s again.
R.