Again, though, as I indicated in my previous post George's comments mainly address frequency response at the amplifier output/speaker input. And flat frequency response at those points does not necessarily mean that the acoustic output of the speaker will have flat frequency response.
Ralph (Atmasphere) stated above that "in an ESL, the efficiency is fairly constant despite the impedance." ("Efficiency" referring to acoustic power out vs. electrical power in). I believe that is generally true. But even if we assume that the efficiency of a given ESL is just a little bit closer to being constant across the frequency range than it is to mirroring the impedance curve, then the minimal variation of amplifier output voltage as a function of load impedance that is characteristic of almost all solid state amps (assuming they are operated within the limits of their voltage, current, power, and thermal capabilities), and hence the increase in power delivery that will occur as impedance decreases, will result in greater frequency response variation in the acoustic output of that ESL than would result with a tube amplifier (operated within its capabilities) whose output impedance is some relatively high value, and whose output voltage therefore varies significantly as a function of varying load impedance.
Apologies for the long sentence :-)
Regards,
-- Al
Ralph (Atmasphere) stated above that "in an ESL, the efficiency is fairly constant despite the impedance." ("Efficiency" referring to acoustic power out vs. electrical power in). I believe that is generally true. But even if we assume that the efficiency of a given ESL is just a little bit closer to being constant across the frequency range than it is to mirroring the impedance curve, then the minimal variation of amplifier output voltage as a function of load impedance that is characteristic of almost all solid state amps (assuming they are operated within the limits of their voltage, current, power, and thermal capabilities), and hence the increase in power delivery that will occur as impedance decreases, will result in greater frequency response variation in the acoustic output of that ESL than would result with a tube amplifier (operated within its capabilities) whose output impedance is some relatively high value, and whose output voltage therefore varies significantly as a function of varying load impedance.
Apologies for the long sentence :-)
Regards,
-- Al