Hi TLS, thank you for your reply. I have designed several loudspeakers myself and I have a basic enough understanding to hear everything your saying and I totally agree, but I personally don't think I addressed my point well enough. I was referring to older model vintage speakers with very atypical pressed paper cones. And the violin was just an analogy but not to be taken seriously! The point I'm trying to get at is when I personally think of these drivers, I dont picture good sound. Of course on paper, high sensitivity has zero correlation to do with bass output, HOWEVER, it is the process of in real life to achieve these high sensitivities in a driver that isnt very large (lets just leave 15 and 18" out for a second here) they have to have abysmal xmax, very light duty construction cones, small triple roll surrounds etc... which then means it suffers low-frequency extension. I've never successfully heard an old, vintage, high sensitivity paper pressed paper driver putting out accurate, deep powerful bass. In a smaller summary, that's the idea I'm trying to express here, and just wanted to share my thoughts with you guys, and most of us don't want our music to be playing at 120db either, so I understand what I'm saying is almost like "yeah no kidding" and the modern interpretation of these speakers have addressed these issues but it was rather food for thought, seeing how loudspeakers have evolved.
Let me first point out that on paper high sensitivity has everything to do with limited bass extension as there is an absolute inverse relationship between flux density and bass extension.
Actually the old vintage drivers are just that. It would be surprising if cone, suspension, surround, and motor systems had not progressed over 80 years plus.
However even then, I think properly used some vintage drivers are not as bad as you maintain. Then as now there has been the spread between junk and excellence.
The first speaker that had any high-Fi pretensions at all was Paul Voight's driver in his Voight corner horn. It had a massive electro magnet. This line continues in the Lowther line of speakers, of small paper coned extremely high flux density horn loaded speakers,
The Altec Voice of the theater and similar products from EV and JBL, where all developed with the cinema in mind. The cinemas back then were larger than now. Power amps were low powered and primitive. So the order of the day, was good coverage of these huge spaces with good spl. and high speech intelligibility.
So you had these massive systems, of which the Altec Voice of the theater was the best known, most widely used and iconic. Do not forget that Thiel and Small had not yet published their famous paper and gave us the first mathematical model for the interaction of driver and cabinet. This of course led to a massive improvement.
The sentinel dates are:-
1825 Kellog and Rice, on moving coil drivers.
1954 and the fifties era: - Harry F. Olson, Bereneck et al with Elctroacoustic analogous circuits.
1961 Thiel and Small with there famous paper in Australia. Only Raymond Cooke CEO and founder of KEF grasped the significance of this paper. So KEF were the first to design drivers and cabinets using this model. The KEF factory at Tovil just outside Maidstone on the banks of the River Medway, was just 15 miles up river from where I lived. So as a curious kid of 14, I had a birds eye view and up close encounter of this momentous development. The first driver designed using these principles was the KEF B 139 bass driver. It is still one of the very best bass drivers of all time. I have 8 in my possession, with six in regular use. The work was not published outside Australia until 1971, when there work was published in the AES journal. So that is the date when improvements in loudspeakers really took off.
Amplifiers were also crude. 1949 was a pivotal year, when British engineer D.T.N. Williamson published his Williamson amp. This was the first amplifier to achieve 0.1% THD. It is widely considered the start of the Hi-Fi era. He worked closely with Peter Walker of Quad and Harold J. Leake to develop increasingly powerful high quality tube amps. Harold Leake in particular produced a range of beautifully crafted tube amps from 10 to 50 watts in the fifties. The Mullard tube manufacturer published excellent amp circuits back then for the DIY builder, which I built as a kid. I built a 33, a 10/10 for myself and a couple of 10s for others. I still have the 10/10. So Hi-Fi as we know it really did start in the UK, and set in train that era of the "Golden Age" of British Audio.
The point is that it took tandem developments in speakers and amplifiers to start the foundation of what we enjoy today.
The fact that a well restored Voice of the Theater set up sounds as good as it does is close to a miracle. Those products defined Cinema sound for generations. Actually I believe they are worthy of great praise and not criticism for what they achieved with so little to give so much pleasure to millions, especially during the dark days of the second world war.