From TalkBass Wiki
This circuit, added to a small board after the Eminence PXB2:500 crossover, adjusts the average sensitivity of the 18 Sound 6ND410 midrange driver downward ~ 3 dB to better match the Eminence 3015LF woofer's sensitivity. It has enough duty rating for even the stoutest use of wattage that the 15/6 can handle. Simply run wires from the high-pass section of the crossover to this fixed-value L-pad, and from it to the midrange driver. One source for the resistors: Parts Connexion.com
Here's a photo of BurningSky's L-pad:
back to Fearfulâ„¢ 12/6 & 15/6