thank you for your answer.
I had not read this characteristic.
I have just made the modification in Mconfig.

with cinema, it is much better.

Meridian : 861v4 /800v4/HD621
Earthquake Sound Cinenova Grande 7 + 2 x CLASSé CA-M400
Cabasse : Passific 3 ; Ambrose 2 ; Baltic 2 ; Sirocco + 2 x Earthquake Sound SuperNova MKVI 15" Special Version ( 1500w).
Chinoppo M9201 + GIEC 5700 + Nvidia Pro
JVC N7 + HD-Fury Wrroom .