Paul, I was glad to read your post about the wood platform. I've
noticed this also and I've come to the conclusion that the 'ideal'
room for coin pianos would have wood floors and wood slat walls, and a
ceiling that is not flat. In other words, the inside of a train depot.
The resonance of the wood seems to reflect the tone of the piano
nicely, and it carries without being too loud. Concrete would reflect
the sound as in the chambers of a pipe organ, but in this case, with a
piano it's almost too loud. I noticed that, at Knott's Berry Farm here
in California, the coin pianos sounded good in the "Calico Ghost Town".
All the buildings are this old wood you'd find in an old "Wild West"
town. Most of the pianos now are not playing that well, but the sound
of the piano comes through.
The wood seems to give the piano tone a 'warmth' that carpet takes
away. Now the question is, what is the best wood to use?