Originally Posted by PrimeTime
A lot of this is semantic wrangling.
"Transconductance" simply means that the output conductance is controlled by the input voltage.
Conductance = 1/Resistance; the unit is, unsurprisingly, the mho ("ohm" spelled backwards). This is a basic property of MOSFET devices. When used in a conventional audio power amplifier circuit, however, the unit becomes a voltage source due to significant amounts of negative voltage feedback.
Speakers respond to current, as that is what activates the electromagnetic transduction. Current, however, doesn't exist in a vacuum. When produced by a power amplifier, which is a constant-voltage source, current becomes the dependent variable (y-axis) which, for a given output voltage, is a function of the complex transducer impedance (x-axis), itself a function of frequency and other complex variables.
Speakers respond to current, as that is what activates the electromagnetic transduction.
BINGO! Tomas and myself have been saying this all along!
When produced by a power amplifier, which is a constant-voltage source,
Amplifiers are not constant voltage sources. This is a misnomer. They're voltage output is proportional to the input, regardless of load in theory; however in real application, Voltage sages as / when impedances drop below nominal. As well evidenced by my previous posts.
Regardless of what type of design an audio amplifier is, it will always output current, and it is current that is the prime mover in powering the speakers motor system, if you will.
Bill has been incorrect, each time that he has directly stated or implied that a speaker ignores current, a speaker doesn't care about current, or anything to the same affect.
The math, measurements and schematic presented within this thread, objectively bear out these truths.