How can i prepare myself mentally for an upcoming subwoofer competition?

Put ear plugs and ear muffs in your back pack.  Put the back pack in your car.

It's pretty hard to mentally prepare for a brainless competetion when you have no brain. 

This has to be a joke, right?

I don't know.

I was never forced into such a dilemma.

Maybe a therapist can help you?

It's a "Car Audio Competition". Not a subwoofer competition. You would need to spend about $12,000 to $15,000 to buy high output alternators, powerful amplifiers over 6,000 watts, powerful subwoofers with high XMAX and RMS power, etc...

Mr. anonymous, Steve Meade is still a healthy living man with his previous 30,000 watt system. But I don't know how his hearing frequencies are now after hearing LOUD high ends and low ends over 100 dB for a prolonged period of years.

Get a good night's sleep. Take earmuffs to the comp.

Pray to Steve Meade the night before. He will be with you in spirit making sure every watt pumps out of your subs with power. 

 (Now that i think about it he might even be there in person, the guy spends most of his time at subwoofer shows)

Get yourself into a sensory deprivation tank.

Get plenty of rest and stay hydrated. No sex until after the competition.