First, your amp, XM-1652Z is a 2x165W RMS into 4 ohms, 2x200W RMS into 2 ohms or 1x400W RMS into 4 ohms, [bridged]
All the above ratings are at 14.4V
RMS = root mean square, and although commonly used for both amps and speakers it is a misnomer, it means the average instantaneous power output measured over a long time, or simply put what the output of an amp is with an acceptable amount of THD, [total harmonic distortion] and as stated it is the only one you need to deal with, yes your amp will make 2x380W @4 ohms and 1x1000W @ 4 ohmsmax however THD is very high and DC output is high, clipping.
Your sub R/F P110S4 is a 10" 4 ohm 150W continuous, [RMS] 300W peak/max.
Again it is the continuous, [RMS] power handling, [150W] that you need to consider.
The long and short of it is you can use the amp to drive the one sub that is still working, however you will have to be careful of the gain setting on the amp.
The first thing to do is test both subs, start by pressing the cone, use both hands and gently press the cone in and out, even pressure over the whole cone is needed, if cone will not move, [seized] sub is N/G, if you hear any “scratching/scraping” sound, sub is N/G.
You will need a multimeter for other tests, but you can do a “continuity” test with amy batt., [a 9V works best] touch the pos.(+) and neg.(-) terminals of the batt. to the pos.(+) and neg.(-) terminals of the speaker, [sub] if the VC, [voice coil] has continuity, the speaker will “pop”, if the pos.(+) of the batt. is on the pos.(+) of the speaker and neg.(-) is to neg.(-) the cone will “pop” out, if reversed the cone will “pop” in.
The batt. test is not an indication of the condition of the VC, only that it is not “open”, [broken].:bowthank:94