Coincidentally, the first commercial stereo records appeared at the end of 1957. Now two loudspeakers were necessary.
To have two makes them rather a dominant presence, at least in the average British living room.
Of course you could just have one ESL-57 paired with another speaker: bizarrely, this was suggested in the original HiFi News review in November 1957, which concluded
It will not suit all tastes, but the reviewer can confidently recommend it as an excellent domestic speaker. As Mr. Briggs has recently demonstrated really convincing stereophonic reproduction with two completely dissimilar speakers, it is seriously suggested that one of the listener’s pair of speakers should be a full range electrostatic
Fortunately, the distinctive curvature of the panel and the perky angling of the little feet can do a great deal for spousal acceptance, if you are lucky enough to have a partner who appreciates 50s design.
Unfortunately, stacking two pairs is going to deprive us of these positive elements, leaving something more like the monolith from 2001 – and even Dave Bowman only had to deal with one of them.