Thanks for the clue-by-4. One more stupid question. I have a pair of Kappa 15's. My take on the efficiency graphs is its a 98dB/W driver. Eminence rates the PSD2002 at 105dB. Does that mean I need the -8dB x-over, or is the PSD2002 more efficient once mounted on a horn? I thought I saw 110dB in one of your x-over docs. thx, Chris