Hi guys and thanks for your rapid response. I have attached a sample of one of my midifiles with all the sysex messages I use. Just to mention, I use a roland mc50 mk2 for creating my files then save them on to my laptop. The sound canvas goes directly into my desk and then thru the PA. I'll try to explain more clearly what i'm trying to achieve: At the start of each file using sysex, I turn on the insertion effect on channel 2 and select 14 Compressor. Now when I scroll down within the compressor window, the settings are - Attack 72, Sustain 100, Post Gain +6, Low Gain +12, High Gain 0dB, +PAN 0, #Level 104, EFX to Rev 40, EFX to Cho 0, EFX to Dly 0. I'ts the EFX to Rev 40 that I want to reduce.. Really all I want is to produce a more punchier, tighter, even volumed bass sound from low notes to high notes on my sc8850..without adding any more equipment to my set-up....I already have one knee replacement.. Just as a matter of interest, can u add compression to individual drums on the 8850? Apologies for repeating from my original post..