hi, I have a 99 sentra gxe, and about a year ago, i put a sony 75 by 4 amp in it, and half the amp (150 W) is powering my JL W6. However, my amp recently crapped and I had to send it in to sony for service. My JL is still sitting there. when I told this to the people that sold it to me, they told me I was "underpowering" the amp, and it damaged the amp. Is that true, or just bull? I hate car audio places because they ALWAYS try and make you spend more than you say you will. So, am I really "underpowering" this JL w6 12''? or will my Sony amp at 150 W suffice? it's now in a ported enclosure, and I'm thinking about getting a sealed enclosure for it. let me know your input! i appreciate it! thanks!