dummy coil? not sure what that means...it's a voice coil and it functions as such. Not using it means that the magnetic force generated by the coil system is halfed...less force to push the cone equals weaker bass. Secondly, as far as I know, based on the current CVR manual, Kicker plainly states that "both coils are to be connected to a source of amplification."

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2004 300M SPECIAL
Alpine CDA 9833
Alpine Pxa-h701
Alpine Rux-c701
Rockford fosgate p400-4
Rockford fosgate p4004
Hifonics BX 1205D
JBL c608 GTi
JBL p693
Infinity 2.5" center channel
Alpine type R 12"(2)
all active SQL set up with 1900 watts rms