What mode were you on for processing? Auto Surround, direct, etc...? I will assume that your setup has your r fronts listed as "small" to allow for control of a sub?, Does it seem like the low end is missing more than anything?
I wanted to setup a better 2 ch. listening experience as well. I found one of the "flaws" with this receiver IMO, is that when setting up the fronts as large, it shuts off the assumed usage of a Sub. SO, the only way to get around this was to tell MCACC that my fronts were Bi-amp. And yes I tore back in to my speakers and separated out the woofers on their own channel and ran those leads based on what the manual told me to, which I think was 2nd zone outputs , (don't worry, I built the speakers in the first place)

When doing this, the sub was still available. Now, I don't have the situation of using a turntable but I can tell you that when listening to 2ch music, it was much better and acted as expected, for my listening. If anything it was what I had to do to make it easy (and lazy) on my part to use just one MCACC config. BUT, I don't have my unit any longer to check but I believe if you go in to MCACC and setup memory slot 2 with a new config, it will hold the large / small speakers settings for each memory...?? might want to look. if that's the case and you can set your fronts to large, you wouldn't have to go bi-amp but maybe in there you could just set the other speakers to off? (again,not 100% on that statement).
Maybe that helps? Sorry as you may have seen above, my 1120 is RIP now..

or I would try it out for you.

Happy Holidays back at ya!
Paul.