I have a 3 cubic foot ported bass cab with a 200 watt 1X15 - 8 ohm speaker loaded in it. I want to upgrade the speaker with either an Eminence Delta 15LF rated at 500 watts or an Eminence Legend rated at 300 watts. The Legend cost about $125. The Delta cost about $100. The Legend has a cast aluminum frame. The Delta has a steel frame. I intend to use the 1X15 - stand alone with an LMII head. What speaker would you use? Thanks.