The paper focuses on changes in the acoustic parameters of multi-purpose audience space for symphonic music without bot architectural and complete reconstruction. Old analog and modern systems with digital signal processing are analyzed using active field control (AFC). The AFC3 system from Yamaha, Moscow, Russia, installed in the Great Hall of the Tyumen Philharmonic is considered. The diagrams of early reflections are obtained by computer acoustical simulation of the Great Hall. The control measurement results confirm the effectiveness of the proposed solutions. The intrinsic reverberation time is 1.1 s. The AFC3 system provides the increase in the reverberation time up to 2.65 s. For the first time in Russia, the electronic shell is constructed for the fly-loft stage in the Tyumen Philharmonic, that allows improving the acoustical conditions for musicians.