Technology has advanced to such an extent that the '30's can realistically be seen as the cave man days, in many respects. Certainly with computer testing and engineering, what can be purchased today for say a week's wages versus the 1930's would be worlds apart. The modern cabinet, drivers, and crossover all benefit greatly from new discoveries, techniques and a body of knowledge WRT making a good speaker that the 1930's can only dream of.
Technology is one thing, another is its application. The size of speakers (i.e.: radiation area) and their efficiency has gone from large and high to small and low, both of which I'd say are among rather fundamental factors in achieving a lifelike sound reproduction, and where advancement in technology can only bring you so far with smaller and less efficient speakers; there's no escaping fundamental physics.
An analogy: think about the state of technology in the 60's in the beginning of the space age, and where it got the Saturn V rocket and its inhabitants: to the moon - a feat that hasn't been replicated since the last moon landing in '72. You'd imagine going to the moon in our present day with its highly advanced technology and crazy computer power would be a piece of cake, relatively speaking, and yet it hasn't happened. A priority, obviously, but some 45 years ago a select group of astronauts stood on the moon and looked at the Earth - having had only the computer power of a poor pocket calculator of todays build. This is not to say the space age in the wake of the Apollo missions has been in vain, but no (wo)man has since gone that far into space and walked on another celestial body.
Making loudspeakers that effectively approaches a lifelike sonic imprinting "simply" requires the will, skill and materials to do so, with no excuse nor catering to size constraints or other marketing-laden interferences. They apparently got off to a good start over 80 years ago, and perhaps part of the recipe here was a predominant reliance on the ears coupled with a goal that involved a natural reference, rather than an industry-established, navel-gazing hi-fi agenda where branding and small size is all-important.
