Question 1

is this subwoofer a powered woofer my system requires a powered subwoofer  YAMAHA YST-FSW050BL2 Advanced YST II & Down-Firing Active Design Subwoofer Single ?

Accepted Answer

Yes, this is a powered sub-woofer than plugs into a standard 110V outlet and connects to your amplifier / receiver / soundbar with an RCA audio cable.

Question 2

How can a 40 Watt* power supply drive a 100 Watt speaker to full output?  Surely, max continuous output cannot exceed 40 Watts, and is probably less than 35, given real world efficiency of power supply and amplifier.  (Remember, this is using line level in, not some other amplifier's power out.) 
   * 40 Watt figure derived from faceplate data of unit - "120V 60Hz 40 Watts".

Accepted Answer

I'm not too certain if you can draw direct parallel between the power supply wattage rating which is AC power, to that of the speakers max output which is DC rms power combined between the fwd firing speaker and the down-firing speaker.....I guess max 50 watts each? The circuits go thru A-D conversion with the PP transformer and amplified to feed to the spkrs so you gotta know how the spkrs are rated as compared to other spkrs and not compared to the power supply rating.

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