Using JL Audio Esub with Merlin VSM

Looking to add a sub or two to Merlin/fila/Oppo 105 combo. Does anyone have experience using different input choices on sub....if so....what were pros/cons.
-high level speaker inputs with BAM in path
-high level speaker input without BAM
-line level using sub x over
-sub out from source/pre....in my case sub out from Oppo 2.1 application

 My room is somewhat small....maybe 15 x 12 x 9h