Loudspeakers have we really made that much progress since the 1930s?

Speaking of old School and builds the Cabinet is at least 1/2 responsible  for the Loudspeakers fidelity . I found a great cabinet builder in TN that uses what myself and many the finest Birch ply made in Apple ply they use only1/16 th thick  laminate sheets  up to 1 inch and the best plays are from cold climate Ruseia and east Poland the grain is tighter and more dense but $$ . 
I am using a never advertised but very Good Audio Nirvana 15 inch Alnico driver 
with Whizzer. In the 5.6 cubic ft driver a Bass reflex with 6 inch port 
where the 13 Cubic foot is their top. At least Audio Nirvana will provide you with 
cabinet building plans when you buy from them.i have owned a audio store for years in the UK and many others . I now have a SE pass labs F6 clone amp 
and Masterpiece 300b preamp Schiit Audio Gungnir Multibit 
and this system is truly engaging and puts realism in the room .
what many people donot realize is that most recordings are lucky yo get under 
40 HZ. My speakers will cleanly go to under a True 35 HZ not on paper 
like most speakers and for only one short burst tuneful articulste standup 
Double Bass or Tympany . For $3k delivered I wasted years avoiding 
single dtiver done right ,Driver,and proper built cabinet  work in synergy .
give it a shot  and if you don't build ask Dave for a quality cabinet builder .
the 5.6 CI  cabinet was $1350'stained and sealed with magnetic grill s for $1500
plus shipping the 15 inch Alnico drivers $1100 a pr.  Don't knock it unless you 
have heard them  using the exact loudspeaker geometry for size driver
and Driver that best suits your room .

Do you have contact info for this cabinet builder in TN?

     It might be useful to think about the evolution of the automobile as an analogy here. A car from the 1930s would be immediately recognizable to us, but over time cars have gotten lighter, smaller, safer, they handle better, are more reliable, routinely go faster, are more efficient, and the list goes on. These improvements (and yes, I think we can all agree that these are improvements) might also be said of speaker design. The industry has access to vastly improved measuring techniques, materials, and about a century of design experience to draw on. Fundamentally, the components of a car haven't changed much since the 1930s: an engine, transmission, suspension, steering mechanism, exhaust system, and a body to enclose it all. Same with speakers: a magnet, a basket, a vibrating membrane...

     What HAS evolved in a major way since the 1930s is music itself and therefore how we listen and what we listen to. Every day, we hear sounds my grandparents could never have imagined. Reproducing those sounds requires innovation not only in speaker design but also in amplification. I'm wondering if the invention of the transistor might not have been one of the driving forces behind speaker design and innovation over the last 50 years or so, and now that we're in the early(ish) days of the popularization of class D amplification, what changes might that precipitate, us having grown so used to today's hyper-resolving electronics?

So..it appears that John is right, there is no innovation in a true meaning of it, just some improvements in certain areas, maybe.
Speaking of cars, not from 30s. The original BMW M3, small and light, was a true driver's car. The same with Porsche. Now look at those modern computers on wheels that those cars have become. I don't need them.

Spot-on Inna and John.....
I get to compare vintage to modern every day in both cars
http://i.imgur.com/ASYO1cY.jpg
and audio
http://i.imgur.com/ddKNHVx.jpg
Give me vintage....😎🎼