Moving them should make the most difference, you can always move the back anyway.
Below is from the Dirac blog:
The two weakest components of a HiFi system are typically the loudspeaker and the room the music is playing in— the second of which is most often overlooked. Even if you’ve invested in a best-in-class HiFi system, the listening room can still have a tremendous effect on the overall sound...
www.dirac.com
"Room resonances and standing waves primarily affect the bass performance. You will hear that certain notes are severely pronounced and sound boomy due to the geometry of the room. Room correction systems need to be careful in compensating for nulls or suck-outs. If there is a signal cancellation, no amount of energy boost will compensate for that. "
From the Audioholics.com's interview with Dirac:
Room EQ: Today the Audioholics have a chat with Mathias Johansson to get the inside scoop on Dirac's room correction products. Click to learn all about Dirac Live and Unison.
www.audioholics.com
"
Mathias Johansson: Normally, Dirac Live does not allow you to boost more than 10 dB. You can lower this by adjusting the target curve. However, narrow dips (nulls) are never compensated, as they are always position dependent in real acoustic space "
"
Audioholics: How do your room correction products help to address the typical issues a room causes (resonances, modal peaks/nulls, etc.)? Does room correction largely negate the need for room treatments for consumers, or would you suggest using both room correction and physical treatments?
Mathias Johansson: No room correction system negates the need for room treatments."
From the Audioholics.com's interview with Audyssey:
The Audioholics interview Chris Kyriakakis in order to learn the ins and outs of Audyssey's MultEQ room correction / auto-calibration system. Bass management, calibration, EQ and more.
www.audioholics.com
"For practical considerations in AVR systems, the filters are set to +9 dB max boost and –20 dB max cut. "
"Audioholics: How do your room correction products help to address the typical issues a room causes (resonances, modal peaks/nulls, etc.)? Does room correction largely negate the need for room treatments for consumers, or would you suggest using both room correction and physical treatments?
Chris Kyriakakis:
We strongly recommend starting with physical treatments whenever possible."
So if those huge dips are due to cancellations/room nulls, there really isn't much Audyssey can do, or it would have done it. You have the mini, so that may help a little, but be careful applying boost. Dirac limits boost the 10 dB max, Audyssey 9 dB and AARC 6 dB. And, as you know, 10 dB means the amp output will increase 10X so that may be too much for your speakers/subwoofers under certain conditions.