I had two 15" Diamond Audio TDX's receiving maybe 350 watts apeice cuz i didnt want to upgrade my alt. I sold one to someone on ebay and the other to a friend. My friend bought a Hifonics BX1605.
After hearing his and mine, i found that with his TDX it can go louder and lower then my four RE12's, but the RE's are so much more musical to me, not to say taht the TDX didnt sound good or anything like that. When you blast that TDX you cant really listen to music properly in my opinion. Overall i am completely happy with decision. Just though i would give you all an update if any of your were interested