Help ARC VT200 taps

I have 4 ohm speakers. The taps are as fallows
+4ohm +2ohm +1ohm
unbal common/ center tap
-16ohm -8ohm -4ohm
Is it as simple as +4 and -4ohms and what the common/center tap for?

You want to hook the Red (+) wire of your speaker cables to the (+) on the amp. Negative/black to(-) on the amp. Each tap has + and - . Reverse this if your system inverts polarity.

Just because you have 4ohm speakers doesn't necessarily mean you should use the 4ohm tap on the amp. Experiment, it won't hurt the amp. You might prefer the sound of the 8ohm tap for instance.
Thanks for the info. Any idea what the center tap/ unbalanced tap is for, no + or - sign?
Thanks, Bill.