I was looking at the specs for the MM1040 and the MM1040um (ultra marine), and they look exactly the same. Although the MM1040 says that the warranty will be voided if used in "free air", and the MM1040um was designed for free air. But there is a $50 price difference, is this a ploy to get more $$?
I know you attach the word "marine" to anything and it increases the price, does polk do this too? :p
I think I want to put this in a box from what I have read, it will sound much better. Can anyone attest to this? Even if the sub is designed for free air?