Mirage sub with speaker level / line input only

I have 2 Mirage Omi 150 bookshelves and a Pio Elite A 35R interfrated @ 45wpc which I am fond of. My borther gave me his Mirage 100w Sub and the sub has ONLY line and speakers inputs.

I prefer to use the speaker level input to the line input.
My pio A 35 intergrated has 2 set of speakers a/b out and they can be used silmultanously.

My question is if I set the pio a 35 to a+b speakers and use A terminal oupt for the Omni 150s and the B terminal output for the Mirage Sub would be a wise move ?

In that set up, Would the output impedance drop to the point that the intergrated will "clip" ?
That should work fine. Powered subs typically present a very high impedance (meaning a negligible load) at their speaker-level inputs, so it will not draw significant power from your amp.

For that reason, also, you don't necessarily need to use as heavy a wire gauge to connect the sub as to connect the main speakers.

BTW, connecting both the sub and the main speakers to the same pair of output terminals on the amp (A or B) should work equally well, although using A+B is most likely physically more convenient.

-- Al