I'm not sure what the controls look like on the MRX, but on my Anthem STR, after I did the ARC correction, I was able to adjust high mid and low. I would recommend option 1, it worked fine for me. I do not have a sub, there is a sub option, but there is also a bass option that did jack up the lows on my Electra's. However; I do like to keep in direct mode, so everything is set to 0 after ARCorrection. The reality is, a lot of recordings are light on bass, and that's the way it was meant to be heard. It is a treat when I run into an album that has punchy, chest-kicking bass right outta the can. Try putting +3dB on Bass, if that doesn't help as much as you want, 0 that back off and add some points to the Sub settings.