unsure which model it is...? i dont know much about systems thats why i got it done by the store
on my first sub i never took it passed 20 on the HU (for all of those who have alpine HU, you will know they go to at least 30, unsure because im not game to go passed 20)
after the 2nd sub was installed and retuned i was told i can go up to 28 on most recordings but i still didnt go passed 20 because it was decent enough
i hope its covered by warranty, the whole install cost close to 3k