Bruce (Bifwynne), re the impedance magnitude and phase angle plots for the S5, while the variation of impedance magnitude as a function of frequency is a good deal less than on many speakers, including your present ones, I would consider the S5's impedance characteristics to be quite demanding.
The impedance magnitude appears to be at or below 3 ohms from around 50 Hz to around 150 Hz, and also throughout the top octave. With phase angles that are significantly negative (capacitive) in much of those regions, including a particularly severe combination of low impedance and highly capacitive phase angles in the 50 to 75 Hz area, where a lot of energy is often required.
See also the post in this thread by Elberoth2 dated 11-29-12.
My guess is that your ARC REF 150 would be able to handle all of that with relative aplomb (using the 4 ohm tap), but I'm not sure that it or most other amps would fully sound their best in doing so.
Just my $0.02. Best,
-- Al
The impedance magnitude appears to be at or below 3 ohms from around 50 Hz to around 150 Hz, and also throughout the top octave. With phase angles that are significantly negative (capacitive) in much of those regions, including a particularly severe combination of low impedance and highly capacitive phase angles in the 50 to 75 Hz area, where a lot of energy is often required.
See also the post in this thread by Elberoth2 dated 11-29-12.
My guess is that your ARC REF 150 would be able to handle all of that with relative aplomb (using the 4 ohm tap), but I'm not sure that it or most other amps would fully sound their best in doing so.
Just my $0.02. Best,
-- Al