I heard from a coworker that to get twice the volume, the amp needs to provide around 10 times the wattage but still I think that 300W is going to be noticeable.

Although I'm not saying a difference in 300 watts really matters to me when we're talking 800W vs 1100W considering I'm only using 350W right now and I'm pretty happy with the volume. I just want a subwoofer with higher power handling so that it doesn't begin to sound sloppy at louder volumes like it currently does.

 

Well as the "story" goes, double the power and (possibly) get an increase of 3db's

 

^ as most have seen it doesn't work that way at SPL in cars (double power and get one or 2 dB)... maybe OK in home audio though

you might see 1dB with the 300 watt add (the 300 watts would have been significant (2 to 3dB) under 500 watts)