Need help! No sound from subwoofer

[socaltiger]

I've got a yamaha rx-v3300 and can't get any sound to my subwoofer. I have a cable from the subwoofer preout into my external amp input (left mono) which is powering my passive sub. Been reading the manual and can't find anything wrong with my setup. Any help is appreciated.

 

[Davemcc]

Do you have a speaker setup menu where you tell the receiver that you have a sub and to turn it on?

 

[socaltiger]

It does and I did. I also set all my speakers to small which should send the LFE to the sub.