What volume should I be able to take my stereo to?

I have a JVC KD-R418 deck set to high gain all my bass treble an mid are at 0 and its hooked up to a Alpine MRP-1000 mono amp and a Alpine 1023D Type R 600RMS 1800peak and the amp from the professional car audio place was set so gain is almost full bass eq is almost 0 and the lp filter was at 100 which I put it down a bit to about 75, my volume on my deck goes to 50 but where from 0-50 should I be able to take it without damaging the sub by pushing it to hard?? and should I maybe change any of my amp settings from what the pros set it to?