It is hard to tell without speaking to the OP, as some one who has worked in motion picture sound I have some thoughts:
Take care of the basics
The compressor will work to raise the level of the softest sounds, while leaving audible levels alone.
Take care of the basics
- Horns are positioned facing the middle of the audience, not the back wall and ceiling.
- Measure your speakers at multiple locations and apply corrective EQ as needed.
- Control resonances to modern standards.
- Minimize or eliminate noise such as A/C units, outside sounds.
- Ensure all 3 speakers are operating optimally. Horns and woofers are both producing correct output.
- Ensure your overall speaker levels are properly calibrated.
- Some movies such as LoTR are produced with excessive dynamic range. To hear the softest voices requires too high a volume, which you then suffer through far too loud effects.
The compressor will work to raise the level of the softest sounds, while leaving audible levels alone.