Colleen, as Ken implied, there's essentially no electrical difference in the two arrangements. The input impedance of the sub amplifier is so high(in the tens of thousands of ohms)that the sub draws practically no power from the receiver and just uses the signal(one form of Ohm's Law is that power equals voltage squared divided by resistance, so if resistance is tens of thousands of ohms, power used is nearly zero)and then amplifies it. Running wire from the receiver to the speaker terminals and then continuing on to the sub, although a bit awkward, is almost as if the sub wasn't there at all, as far as the speakers are concerned.
