When you ask for Power Resistors always specify NON INDUCTIVE.Metal-Mite®Aluminum Housed Axial Lead Wirewound, 5 watt to 50 watts
http://www.ohmite.com/cgi-bin/showpage.cgi?product=89_series
Audio Gold Resistor Family, specifically designed for high-end loudspeaker, 3 watt to 50 watts
http://www.ohmite.com/cgi-bin/showpage.cgi?product=audiogold