I would imagine impedance would only be affected if using a passive sub, I don't think a powered sub would make any difference. My BK XLS200 is connected this way, along with a pair of Celestion 5s, and the amp (Amptastic Mini-1) seems perfectly happy
I just dropped in, to see what condition my condition was in
T/T: Inspire Monarch, X200 tonearm, Ortofon Quintet Blue. Phono: Project Tube Box CD: Marantz CD6006 (UK Edition); Amp: Musical Fidelity A5 Integrated.
Speakers: Zu Omen Def, REL T9i subwoofer. Cables: Atlas Equator interconnects, Atlas Hyper 3.0 speaker cables
T'other system:
Echo Dot, Amptastic Mini One,Arcam A75 integrated, Celestion 5's, BK XLS-200 DF
A/V:
LG 55" OLED, Panasonic Blu Ray, Sony a/v amp, MA Radius speakers, REL Storm sub
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