My SVS subwoofer will not turn on from auto mode

mattg3 - I have a pair of SVS subs. I was surprised to read the subwoofer gain setting could have any effect on waking up the subs. When in "auto", mine come out of standby as soon as the music starts (i.e., as soon as the pre-amp starts sending line level signal to them) even when gain is turned all the way down. With the speakers I’m running right now, gain is normally at 9 o’clock. Not sure I understood your question about adjusting subwoofer trim at the receiver.  I guess the Yamaha is a home-theater device?  One very obvious thing to check is bass content of what you play that DOESN'T wake them.  Could it be there is just no bass signal going to them?  Does failure to wake happen with different pieces of music??

Hope you get it sorted out. Worst case, if no satisfaction from SVS (I’ll be disappointed in them), wake ’em up manually (as I’m sure you could figure out on your own! :-) Good luck.

SVS told me that Yamaha receivers have a low bass signal so I may just have to wake them up manually.It seems that cds played on my Oppo DVD player don't wake  it up. With dvds it seems to wake up sometimes. Im going to buy a dedicated subwoofer cable to see if that helps.  Thanks for your help

Just ordered some Blue Jeans LC-1 sub cable off Amazon.  Flexible, well shielded and affordable.  Have been using some unshielded interconnects.  Figured it was about time to do things right.  You can always spend way more than the BJC, but why? 

1. Try a 'Y' rca cable connect the receiver LFE to both L/R line input on the sub, if made no difference then
 
2. If your AV Receiver has pre-out and you have a pair full range front main speaker, you can try connect the sub line input to the receiver front L/R pre-out, and re-configure the receiver setup to full range main L/R speakers, select ’No sub’ for the LFE channel, set the subwoofer internal low pass filter to 80Hz or lower. Hopefully the stereo full range pre-out signal will wake up the sub easier.