I know this is an odd one guys but I'm serious and was hoping that one of the "speaker gurus" on here might be able to give me a better understanding of SPL, decibels, etc... I have heard of competition car stereo systems that are literally capable of killing people. What I'm wondering is- A: Is this true? B: If it is then- What sound pressure levels are needed to theoretically kill or seriously injure human beings, fuzzy woodland creatures, etc...? What frequencies, and at what levels can/does this occur? How much power would be needed to achieve these levels? I'm having a disagreement with a fellow bassist who does not think these things are capable of happening. He is standing on the argument that if this was so people would be dropping dead at concerts all over the world. I would like to provide him with the actual physics, numbers, whatever... of the phenomena so that he might believe me. I will then construct a massive RIG-O-DEATH and travel the galaxy destroying all those who defy my wrath! Mwuu HA-AA-AA-AA! I mean, um... provide him with the math! Also, the formula to determine how loud a given speaker enclosure/design will get would be pretty awesome too. bgavin?