mcintosh amps any one can explain impedance taps

my maggies are 4 omhs so the 2 omh tap is the best match right I see the meters on amp not going as high when useing the the 2 omh taps

ok thanks the 2 ohm is the winner here there ribon drivers and i think they dip alot of the time

al i did try 4 ohm taps the amp was gettig to close to the end were i like to play my music my amp is solid state it seam to have the same out put but useing the 2omh taps does two things lowered my out put meters and is more detailed in the sound i think my maggies dip down more then i thaught thanks

there 4 omh macrojack and like power