Good horn loaded speakers were designed & made in the 40’s, 50’s &60’s(Klipsch, Western Electric, Altec), electrostatics in the 50’s, Good acoustic suspension & ported woofers in the 50’s & 60’s, (AR, KLH, Advent, JBL) AMT tweeters from the early 70’s (ESS), good planars & ribbons in the 70’s & 80’s (Magnapan , Infinity)good dome midrange driver in the late 70’s (ATC), good full range driver in the 70’s ( Ohm) to name just some of the technology that have all stood the test of time.
Cabinet technology, crossover design & component quality, internal wiring & binding post improvements have all added incremental sound improvements but unfortunately at often substantial cost increases beyond simple inflationary reasonability.