Quoted from MustangPaul:
I'll post when I get one in. Why does it sound better, because it goes into the subs RCA inputs, that High Z, Low Z thing or is it the board?
You are tapping a direct board to receive a "pure" mono signal (that is what the Pinnovators SAM sub board does, there is no amplification) that has no interference (essentially you are running two speaker sets), versus piggybacking. It has nothing to do with using shielded RCA connectors, which split the signal back again from the 3.5mm male connector.
Think of this way:
If you play music on a set of speakers that are already amplified, and then clip alligator clips on the back of the speakers to run more speakers off of those speakers what happens?
SIGNAL DEGRADATION and loss of amplification.
You can actually pick it up with your ears if you listen closely.
When a person wants to run additional speakers from a main sound system they usually end up using a dedicated amplifier board which provides independent outputs.
The subwoofer can still boost the signal, but not nearly has high as a pure signal that has not been touched.
That is why a small subwoofer can sound "mighty" by using the board instead of alligator clips, as it is just being used as it was supposed to be in the first place.
Many stereo systems have external dedicated subwoofer ports for the same reason.
(Well, that is not entirely true there is amplification on the MPU board but not nearly as high as a proper stereo amplifier, which is clearly demonstrated by the use of improved speakers such as Pinball Pro, which uses a control board)
I cannot speak for Pinnovators multi-subwoofer "black box", as I do not have one to review the internals beyond the website description.