I have been reading several conflicting ways to connect my 7004's & 2500 & Rythmik sub. Some say to connect them with just speaker wire & that will give me plenty of use of the built in subs. Others say this will not allow me to benefit from the 7004's built in subs, that I must connect them using the LFE. Which is correct??? I want to benefit from the 7004's + benefit from the F12SE sub. I am not sure that I can connect the 7004's, 2500 + the stand alone sub from the sub out on the older Pioneer 45 receiver that I have. In time, I want to upgrade that too, but for now I will have to make due.
The BP7004's tweeter, midrange, and subwoofer drivers share the same crossover network - the Linkwitz Riley Crossover.
Any bass signal (including LFE) fed to the BP7004 via speaker wire will be sent automatically to the built-in internal subwoofer.
However, if your receiver is like my Denon receiver, when you set it up to have at least one subwoofer (like Rythmik sub), and lowest crossover point is 40Hz, it will automatically send all signals from < 40Hz to the subwoofer and all signals > 40Hz to the main speakers (BP7004).
If you set the receiver up as NO SUBWOOFER, then all signal from 20Hz - 20kHz will be sent to the BP7004, and thus the internal sub would get all bass signal.
Thus if you ALSO fed the BP7004 via the LFE input, you will then get signal < 40Hz sent to the BP7004's internal sub.
However, I don't think the BP7004's internal sub can handle that much bass below 30Hz anyway.
So I would recommend just connecting the speaker wires to the 7004, and forget about the LFE on the 7004. Let the 7004 handle all the frequency from 40Hz - 20kHz, and let the Rythmik sub handle all < 40Hz signal.
