Chadeffect, i agree with you, its difficult to obtain a good result with direct XLR connection, because it depends from preamp line output. I came back today to usual connection, using Transparent Reference between medium and bass-treble, instead of Avantgarde cables, and its better
Avantgarde XLR subwoofer connection
I actually drive Avantgarde Uno with direct connection from preamp line out to XLR subwoofer connection, and i have the feeling that bass is greatly improved, compared to classical connection. Do you have the same experience? Marc from France ( forgive me for my poor english...)