Synergistic Research Atmosphere UEFs level 1 vs SR Atmosphere X's level 1

Haven't compared them to each other, but Atmosphere level 3 are superb, with excellent bass, transparency without edge or glare, and a really nice big deep 3D sound stage.

The Atmosphere "UEF" is the previous generation, and the Atmosphere "X" is the current version. Foundation line is the most recent tier, below the Atmosphere X tier.

I have a set of SR Foundation cables (speakers, interconnects, power). I used to believe cables didn’t matter until I borrowed a set of these. I couldn’t order them fast enough. Ink black background and I have high efficiency horns with tube amps. Improved the soundstage and details. My wife noticed the difference immediately.