Your opinions on an AC incident

I bought a new power cord for the subwoofer and instead of using the dedicated line w/PS Audio power port I plugged it into a regular outlet which happens to be the first outlet on that circuit about 5 or 6 ft. from the breaker box.It sounded great,tighter articulate bass,better dynamics,etc.But it was also grainy.So I plugged it into the dedicated line[26 ft. from breaker box] which means running it in front of a doorway where it cannot remain,[ the previous cord was flat enough to fit under a cord cover]but just to hear the difference.

The grain was gone,but the entire presentation became smooth and veiled.I don't know if the power port is to blame or the length of the wiring run.So my next move should be which of the following?
#1 Run about 10 ft. of romex from the power port to another power port close to the sub, basicly having two outlets on the dedicated circuit.

#2 Replace the cheap outlet on the 1st circuit closest to the breaker box with a power port.

#3 Replace the power port with two better performing outlets,and on the same line or the separate lines?

Any opinions or similar experiences will be welcome