I realize my experience is with the Essences so it might not apply exactly to the Omen. However, the both share the same 10 inch wideband driver. Compared to the 4 ohm tap, the 8 ohm tap delivers a crisper, faster, more open presentation. Until my speakers settled in a bit, I felt it was a bit too "in your face." So I tried the 4 ohm tap and found it smoothed things out a bit. The down side was the 4 ohm tap made things a bit too polite. Not offensive in any way and some listeners might prefer it over the 8. I thought the highs were rolled off a bit and the overall presentation lacked some air. A good demo would be Black Prarie's "Red Rocking Chair." In the end I think it's a very subjective call. Use the tap that produces the results you like the most.
