SubSerpent

I've been using the DWedit program to try and increase the range at which my sub can hear another one. I know certain things like range, sub speed, etc play factor but it always seems like my Seawolf begins to hear another sub at about 5-10 nm when the other sub is doing high speeds. Is there a way to boost it up to 15nm or higher that I can hear them in passive sonar mode? Where is this "editable" within the DWedit program? The most I have been able to find is how to make my passive sonar 100% accurate which is not what I want. I don't want it to be 100% right all the time, but I do wish to be able to hear other submerged contacts at further ranges.