4200 watt burp -- 149.8 dB
Two 3500s @ 1 ohm each nominal strapped, only set as high as the sub would allow before acting funny mechanically (leaving gap).
I did not clamp it at 149.1 but I was running just two 2000s @ 1 ohm each nominal... my rise is to ~3 ohms per amp. So it was ALOT less power. I did not gain much going to 3500s as it wasn't liking it mechanically.
I think this sub would do better with alot less port area... IMO, it doesn't have enough motor force to really pressurize this giant port. But all in all it did quite well.