EVs, Klipsch, Altec and JBL all are not 1930s. The Altec A7 you use as a example of poor bass its again not a 1930s design but is a affordable down sized design so expecting that to have deep bass and to be a example of design faults from the 1930s is very off. And you say this- Most older speakers simply can’t reproduce it right- certainly nothing from the 30s can- again since you admit no experience with 1930s how can you say such a all encompassing thing. Your argument about old wiring well I see cloths back in and costly as all heck and noted more than a few modern builders that are using screw type connections and bakelite. And you mention a 98db loudspeaker that good to 20hz I would like to see that since Hoffmans iron law it would have to be giant. So thanks for replying etc but you haven't changed my mind.OK- so 50s tech is out- the gist I'm getting here is that for you the 1930s was the pinnacle of loudspeaker technology? Is that a fair statement?
Could you point out the spot where I admit to no experience with 30's loudspeakers? I don't think that is correct. Like Al, I've done lots of restoration of older pre-war radios, some of which were rather sophisticated, in particular several large Zeniths (our Novacron amp takes its design aesthetic from a pre-war Zenith) and an Allwave Scott. I've also had exposure to older Western Electric- the large 'Ramhorn' system (there's a set here in the Twin Cities), and at the Munich show there has been for several years a Western Electric system running in a large room that featured 13A horns. I thought it was one of the better sounding rooms at the show- when it was working (one day when I auditioned it one channel was weak).
But one thing that system simple could not do (despite the very large Altec subs) was play deep bass, although the Altec did sound quite nice.
If you want to see the speakers that go to 20Hz, the speaker I have is a custom T-3 made by Classic Audio Loudspeakers. Normally they cut off at 22Hz but I had my cabinets made a bit larger so they would go to 20Hz. They are the size of a mid-sized refrigerator, about 5 1/2 feet high and employ a pair of 15" high-excursion woofers port-loaded.
That speaker employs a field-coil powered midrange that uses a 3" beryllium diaphragm which in turn has a Kapton surround. This technology did not exist even 30 years ago let alone the 1930s (although field coils were the only game in town back then)! The Kapton surround keeps the diaphragm from cracking and failing and reduces artifacts brought on by low frequencies. The speaker uses a 6db slope crossed over at 500Hz so this is rather important! Because the diaphragm is lighter and has no breakups, it is smoother and more detailed than compression drivers that don't use the same technology, which is to say: all drivers made in the 1930s. Since the field coil has to be powered by a power supply, the power supply is thus part of the improvement: technology that simply didn't exist back in the 1930s. I know these days a lot of people go for Tungar rectifiers (which by all accounts seem to introduce hum). I have a box of them sitting in my office. The hum comes from the simple fact that the power supply can't be properly bypassed (without damaging the Tungar). This means that a certain amount of intermodulation with the hum frequency is impossible to avoid. That's a coloration. You might like it, but there is no way its more accurate!