Well the Type R's are a very capable sub. It can be used for SQ, SQL or even SPL if in the right install. They are no where in the same league of the "supersubs" but is a very good sub none the less. It holds it's own agents w6v2's and other subs like that. There are others better (XXX, W7, etc.) but for $100 each you can't go wrong. Plus Alpine has the new Type X comming out... I wonder how that will stack up to the rest of the big boys.