[TsukiNick]

Well I would like to easily switch from using speakers + sub to headphones, but when I plug my headphones in and disable the 'A' Speakers, the Pre-Amp Subwoofer stays on.  I was wondering if there is an easy way of doing this, other than turning off my subwoofer with a powerstrip (My current solution)
 
I don't know why it would be in the design to keep the subwoofer on while using headphones...perhaps the folks at Onkyo thinks headphones need more bass...enough to need a subwoofer in conjunction with them.

 

[Dyaems]

get a k1000 or a stax and leave the subwoofers on is another solution xD
 
there should be a settings on some receivers to disable the sub but maybe your onkyo doesnt have that. my previous (now dead) sansui receiver has that settings/switch haha