Inverted Amplifiers

My concern is with the proper setting of the powered subwoofers that are part of my speaker system. The speaker manufacturer's instructions state that toggle switches on the subwoofer modules should be positioned one way if the amplifier inverts and the other way if the amplifier does not. But the speaker manufacturer's manual does not tell me how to tell one type of amplifier from the other.

Thanks for the information on setting up subs. In my case the actual setting up is easier. The main modules (tweeters and mid-subs) bolt on to the subwoofer modules, so the problem of positioning subs is taken care of. And the manufacturer recommends values for most of the various subwoofer settings. The end user (me) only has to choose two settings: the volume of the subs, set by ear to complement the volume of the main modules (no problem for me), and the matter of deciding whether the main amplifier is inverting or non-inverting. The phase settings on the subwoofers have only two values: 180 (for non-inverting amps) and 0 (for inverting amps). So my question is most immediately about amplifiers rather than about subwoofers.

Many thnks to all of the commentators! Your information should help me get the most out of my system.