OK. Given that, and pending any further info you might be able to provide after the equipment is unboxed, and given also that the 604c is specified as an 8 ohm driver, I suspect that with this particular equipment what would be best is:
-- Connect Output 1 to the amps via the shortest possible cable length. And preferably with cables having low capacitance, for example Blue Jeans LC-1 (12 pf/foot).
-- Connect Output 2 to the sub’s crossover/amplifier via whatever cable length is necessary. If the output impedance of Output 1 with the cap upgrade is anything remotely close to the original 100K spec it would not work well with the sub.
-- Connect the speakers to the amps via whatever cable length is necessary.
Generally speaking, low speaker impedance (which is not the case here) tends to increase the importance of minimizing speaker cable length. High output impedance of a component providing a line-level signal (which is certainly the case here) tends to increase the importance of minimizing interconnect length (although much less so in the case of a sub, for which cable effects on the treble region are unimportant). The use of unbalanced as opposed to balanced interconnections also tends to increase the importance of minimizing interconnect length.
Again generally speaking, my reading of the many previous threads in which the long speaker cable/short interconnect vs. short speaker cable/long interconnect subject has been discussed has been the same as yours, that "the preponderance of opinion is to put the amps near the speakers" (quoting from one of your earlier posts). However the specifics of your particular equipment appear to greatly overshadow any such generalities. Bill (Grannyring) had it right!
Good luck. Regards,
-- Al
-- Connect Output 1 to the amps via the shortest possible cable length. And preferably with cables having low capacitance, for example Blue Jeans LC-1 (12 pf/foot).
-- Connect Output 2 to the sub’s crossover/amplifier via whatever cable length is necessary. If the output impedance of Output 1 with the cap upgrade is anything remotely close to the original 100K spec it would not work well with the sub.
-- Connect the speakers to the amps via whatever cable length is necessary.
Generally speaking, low speaker impedance (which is not the case here) tends to increase the importance of minimizing speaker cable length. High output impedance of a component providing a line-level signal (which is certainly the case here) tends to increase the importance of minimizing interconnect length (although much less so in the case of a sub, for which cable effects on the treble region are unimportant). The use of unbalanced as opposed to balanced interconnections also tends to increase the importance of minimizing interconnect length.
Again generally speaking, my reading of the many previous threads in which the long speaker cable/short interconnect vs. short speaker cable/long interconnect subject has been discussed has been the same as yours, that "the preponderance of opinion is to put the amps near the speakers" (quoting from one of your earlier posts). However the specifics of your particular equipment appear to greatly overshadow any such generalities. Bill (Grannyring) had it right!
Good luck. Regards,
-- Al