The Cardas room setup uses the short wall as front. From your description, it sounds like your front wall is the long wall.
In either case, 10 feet is probably too far from the front wall (behind the speakers).
A search came up with this site which may help:
room setup
My REL Stadium III is set in the room using the easy steps from the distributor's website and it sounds great. It dials in at B2, 34 hz on the chart. I have not used a meter to determine the speaker performance, but that is the bottom end spec for the maggies. Nearly every recording in my collection benefits from the sub providing the music below 35 hz., where the maggies roll off. I use the high level input to the REL from the amp and do not have any degradation of the midrange.
I also suggest getting stands from Mye Sound for your MG3.6R speakers.
In either case, 10 feet is probably too far from the front wall (behind the speakers).
A search came up with this site which may help:
room setup
My REL Stadium III is set in the room using the easy steps from the distributor's website and it sounds great. It dials in at B2, 34 hz on the chart. I have not used a meter to determine the speaker performance, but that is the bottom end spec for the maggies. Nearly every recording in my collection benefits from the sub providing the music below 35 hz., where the maggies roll off. I use the high level input to the REL from the amp and do not have any degradation of the midrange.
I also suggest getting stands from Mye Sound for your MG3.6R speakers.