It could be imagination, born of the very sight of them. In fact, that is the most likely explanation, given that sighted listening tests keep resulting in people being so certain it is physically real, yet this contradicts the only blind test we have access to that has even the slightest credence, which sees the organiser reporting that subjects were very often amazed when it was revealed which one they were just listening to.
What we don’t want to do, if we are going to be evidence-based about cause and effect, is fall into the trap of misattribution, where we assume something must be in the sound waves, with no more evidence than sighted listening reports (which are proven to be no way to determine anything about the sound waves), then cast about looking for the physical attributes that caused it to be in the sound waves. That would be a case of cart-before-the-horse.
@Newman In terms of the need for blind testing to be absolutely sure of differences and preferences, I'm in alignment with you.
Though in this specific situation I can't say I share your same level of conviction that it's imagination. Why?
1) Because unlike wires, DACs, and other equipment with often non-exsitent differences, listeners to these speakers tend to
share a common perception and description of these differences between speakers (yes, it could be expectation bias)
2) The differences heard also mirror the respective brands product differentiation objectives
3) Engineers from the company have also commented on these objectives, preferences, and differences
Reasons I may agree with you include the blind shootout leading listens to say the Salon 2 was more dynamic (in fact that pretty strongly supports your position!)
Overall I'm curious and open minded, and not dismissive of either perspective. At the same time I know what I perceived, even if the perception isn't objectively 'real'. In the absence of my own rigorous blind test of both speakers fully optimized, I choose to follow my personal perceptions because that's all I--and probably 99.999% of speakers buyers--have.
FWIW, I have personally never been able to hear differences in DACs, and wires.
Tangential question for the group... It's generally accepted that the Harman preference score reliably differentiates between speakers with on and off axis frequency response non-linearities, resonances, and poor bass response. And those preferences hold between mono and stereo (but easier to differentiate in mono). Do we actually know if two equally well engineered speakers-- both fully optimized with EQ and placement, but with different dispersion widths--would always have the same preference between stereo and mono? Has that ever been scientifically validated?