i found the best sound for mine was to just set the 2 towers to large and the center to small. the bass from the fronts is great. i also use a sub but i dont really need it all the time because of the bass coming from the towers is so good.
in response to the klipsch v.s. def tech question:
it is true that either you love horns or you dont. i thought klipsch was great when compared to other speakers at similar listening points. but the louder klipsch got the harder on my ears they were. also the longer i listened to them the more i got tired listening to them. with the def techs i experienced the complete opposite. they sounded great at low and high volumes. music i auditioned with the klipsch sounded much smoother and just overall better on the def techs.
Pioneer 5010FD, Samsung 55hu8550, Panny 42PZ85U, Denon 4308, B&W 600's, HSU VTF-3 MK3, harmony 1000, PS4, Xbox One, Sony BDP S350, TiVo Roamio multi room setup