Hi Sunnyjim, The parallel hookup was the way I did it when I had them. I did not invert the top pair. The bass of the setup was pretty good and the overall impression was positive of the setup from memory. How they would sound to me today is another matter. My guess is they would be somewhat "thickish" sounding. To answer your question, stacking Advents was a pretty large difference (for the better)over a single pair.......Frank
