I had a soundstream xxx-6500 on a single 18 @1 ohm about 4,000 rms, and it took it fine. in fact i used this same sub @ a local comp with the gain opened and the sub never even broke a sweat. The sub belongs to my nephew, i just borrowed it for a few days. fi makes one of the most abuse tolerant subs i have ever played with. If you look in the general section there is a thread called fi demo in Hawaii, scroll down and you will see a video of my car taken on the day of the competition. its the ugly red hatch the install was done in 2 days so i apologize for the messy install, and the but ugly wall. oh on a side note, i also had a chance to change the ports and tune low to see if the sub could take 4000 watts @ 30hz, and it took it like a champ. I did set the gain on my amp with a scope so of course there was no clipping going to the sub. the car took first place in its perspective class. hope this helps, aloha.
