Hey David-ten,
I agree with what Kenny said about more drivers lowering the noise floor. I would add by using much higher parts in the crossover, higher grade drivers, and an the heavier/thicker construction of the overall cabinet are contributing to the total transparency/clarity in the Ulf's performance.
Just wanted to share about a great new find in power cords that I clearly hear out performing my reference Harmonix Studio Master cords in my system. In my professional work the website I write for does not do reviews on IC's, speaker wire, or power cords. However, since I have had the DI's and the Ulf's in for review I have started to experiment with different power cords on my gear because I easily hear the differences positive or negative through either speaker. My reference cords have been the Harmonix Studio Master's which are great sounding and cost around $1,500.00 for a six footer. Well, Mike from Audio Archon, who is a Tekton dealer, wanted me to audition a power cord which he hand builds with some of the finest materials and sales for whopping $250.00! I have tried at least three other power cords from very well known and regarded companies that cost anywhere from $2,500.00 up to $4,200.00 for a six foot cord. None of them were any better in my system then the Studio Master cords. The Audio Archon cord was the first that out performed the Harmonix cord across the total (dynamics, purity of tone, more overall dynamics) spectrum regardless of what piece of gear I put it on. Remember, this freaking cord only costs $250.00!
Just like the MicroZotl preamp and the DI's are disruptive products because of how they "snap" the cost vs performance ratio to bits, I now would add this power cord to the list.