Quote: Amen on that. I have my sub just for accentuating the bass (just a little over-emphasized to compensate for the road noise), but from time to time I like to turn that s**t loud... and it can get really loud, I think the "best" measurement I got was 136dB @ 60hz, which means near-instant ear damage, so yeah it's dangerous. And thats only out of a single propperly amplified 500rms Alpine Type R, don't know how much power you have, but assuming you have 1000rms that would be approximately +3dB over my mark. I know it's bad, it's just that it's so awesome to actually feel the power of the woofers from time to time... By the way, JL Audio has an iPhone / iPod app for basic SPL measurement. I'm not sure if it supports an external mic or just the iPhones, but it can give you a rough estimate if you don't want to spend on a calibrated mic.