Directions...

Is cannabis legal in your state?

 Face the Music !!

Both systems, south. Now, OP tell me why it matters?

How did I end up here?
https://www.youtube.com/watch?v=CWwf-1iwD4s

If you lie on the floor when listening, orientation is important.

What is the air speed velocity of a fully laden swallow?

Ask your Lima as nobody knows what you're taking about.

I face my system and according to my phone that's almost due south but a little bit east.

What is the air speed velocity of a fully laden swallow?

24 MPH

I face East with the living room system(s).

I face North when on the iMac/puter.

I face East when when watching TV (our only TV is @ the foot of our bed).

I face creepy people, like MC, mostly here on A’gon.

DeKay

I spin in my chair.....it's called surround sound!

Facing away from the system.  Music hit the ears faster and blacker blacks, much bigger soundstage.

North for main and south for second. But never at the same time.

Everything's better to the North, read Scientology's book of wisdom, your in harmony with the earths rotational axis.
And an amp should be rotated so when you put your new $150+ fuse into it, the head of the fuse (amperage stamped end) should point North.

Cheers George  

George your North is our south, therefore I'm gonna with EAST.

Proper chakra alignment, all powerful in stereo harmony.. 

It's also where the electrical outlets are..  Geezzzz!!!

NW 311,8 deg.

I have never heard of this tweak. Do I need a clock in the room? 

No clock needed, compass maybe. You should follow Feng Shui principles 😉 for best harmony.

The way science works, if you want to know the air speed velocity you perform experiments. All the science and logic you need to be an audiophile: https://www.youtube.com/watch?v=rf71YotfykQ