[MrFixr55]

Hi Folks, I am differentiating between a "Cone" speaker and the modern dynamic speaker.  Here was the evolution:

• Marconi era to about 1924:  Headphones, 1,000-2,000 ohms.  Worked with crystal radios and early tube sets.
  
• Early 1920s: Horn speakers, 1,000-2,000 Ohms, the sound producing element was very similar to a headphone. Requires more power than a headphone, at least one stage of tube amplification was needed to drive the horn.
  
• Early - mid 1920s: Magnetic Cone speakers.  Speaker driven by a magnetic reed "motor".  Speaker impedance was between 1,000 and 2,000 Ohms.  Required more power than either horn or headphones.  Usually required a "power tube", UV120 (35mW at 135V), UX112A (30 mW at 90V, 115mW at 135V) or UX171A (125mW at 90V,370mW at 135V, 700mW at 180V) Examples include A-K Model E, E2, E3; RCA 100, 100A, Crosley Musicone, Timmons Talker.  RCA 100A, 100B and 103 included an LC filter to filter out highs to lessen the harshness caused by distortion.
  
• 1926 to current: Rice-Kellog Dynamic Speaker.  Low impedance (1.0-16 Ohm) cylindrical "voice coil", acting with / against an electromagnet or permanent magnet "field".  Requires a transformer to match to tube' stated load resistance.  requires more power to drive than a magnetic cone speaker of the same cone size.  However, of all of the above speaker types, the dynamic speaker delivers the best fidelity.
  

Hope that this clarifies my position.