Introduced in 1929, the Western Electric 16A horn is a product of the early days of talking motion pictures. The 16A was intended as a compact solution for a horn speaker system to be mounted behind the movie screen hanging on chains. At 400 pounds and almost 3m. wide, the idea "compact" is relative.
Sound systems for movie theaters, that's what we're talking about here. Silbatone Acoustics makes high end audio gear for "serious music listeners". They draw their inspiration from the Western Electric sound systems installed in movie theaters, back before the accountants got into the act. Most of the pictures on their website give no sense of scale. The speaker in the picture above is ten feet wide (including the weird "ears" sticking out on either side). That's a bookcase on the right side of the picture.
To drive big speakers you need big amplifiers. Here's a stack of Western Electric Model 46 Amplifiers:
Via Scott. Who else?