No Bass with 5-Channel Analog Inputs


I am using the 5.1 analog outputs out my Oppo UDP-205 to connect to a very-old Yamaha RX-V995 that was produced way before HDMI. I'm doing this to take advantage of the superior DAC in the OPPO. I can't seem to get any bass out of the system this way. Using the exterior DAC nullifies all adjustment on the Yamaha. I have all speakers set to "small" in the Oppo's speaker set-up, and I have tried adjusting the cross-over as well. I get plenty of bass when I bypass the OPPO when watching TV. My OPPO BDP-95 did the same thing when I connected it this way. I used to be able to rattle windows when connecting disc spinners through the 2-channel inputs. Does anyone have any ideas on other settings I can adjust on the Oppo to get more bass?

audiostick
Yes, I have the Subwoofer connected to the Yamaha with bass setting set to "Both" so that my Mains and Sub share Bass frequencies.

I see that some Receivers have feature to allow for +dbs boost for Subwoofer when using analog inputs.  Unfortunately, mine does not.
Since your Yamaha " nullifies all adjustment," I would focus on the Oppo to first make sure that you are getting signals from all the output channels. 
(1) Does the FR/FL channels change/respond at all to changes in the Oppo of level and/or crossover for BM?
(2) With careful manipulation of the volume control on the Yamaha, connect the .1 output of the Oppo to the FR/FL input of the Yamaha and determine if there is a signal and/or if that signal is affected by changes (in the Oppo) of level and/or crossover for BM?
Yes the FR/FL do respond to large/small speaker selection in the Oppo.

I think I follow what you are suggesting here.  The Receiver may not be receiving/ processing the (.1) subwoofer signal?  I know it is not the Oppo since it has done the same thing with two different Oppo's.

I will pull interconnects the first chance I get.  Thanks!