Hal Davis said in passing that amplified radios "actually had been
available since circa 1922."

I was an electronics fan from about 1950 and was in a club where we had
been given all the old radios from people's attics.  Quite a business
was made converting them from the superheterodyne design [with its
inherent distortion] to TRF (tuned radio frequency), which meant making
several identical variable tuned circuits to amplify the signal through
and achieving in the process, far better music reproduction.

Anyway, this is just to say that the early loudspeakers circa 1922 were
moving-iron affairs and gave an output not dissimilar to a cylinder
phonograph.  Respectable sound reproduction didn't come along until the
moving-coil loudspeaker, round about 1928.  By 1930 radios were better
than the small ones are now.  It was this device, as well as electrical
recording of 78 rpm records, that sounded the death-knell of the player
piano.

Dan Wilson, London