Hearing is a really nice thing to have. I marched snare in h/s for 4 years and vanguard cadet corps last year. Next year I plan to do a corps if I don't get cut. A while ago I got scared because my ears were cutting out when I was at a concert because of playing snare. However, my ears haven't done that in a long time. If your system is tuned very clean and you have very balanced highs you can withstand a lot more than clipping subs with cranked highs. However, 158db is insane. You're seriously going to be having hearing problems in the immediate future if you keep running your system that loud. However, having a comp spl car doesn't mean you have to have your system cranked while you're in it. You can always keep your vol low for the daily drive but at the comps crank it while you're outside of the car to get that 158db+. Anyways, good luck with your hearing and the spl comps. Peace.
-Ryan