the conclusion could be, that the speaker voice coil impedance (and mechanics) is the biggest factor (by a wide margin) in stopping the resonance condition, the speaker leads and amp output impedance coming in second, atleast through the lower range of frequencies, where we are usually concerned with base response and resonance, in short, mostly, it is the mechanical design of the speaker resonance, resistance, etc, is what causes it to flap about at resonance.
A SET amps higher output impedance plays with the FR, as well as generating a more complex harmonic structure from the very design of the SET itself. The simple ideal goal would be to stop all power going out to the speaker at its resonance point, or reduce it as it approaches resonance, the SET amp reduces its output power, the solid state amp reduces voltage. SET tubbiness at low frequencies is about harmonic distortions and poor output transformer design, the better the output transformer, the less the harmonic distortion at low frequencies and the "tighter" the bass due to that alone.
Output impedance does not "grip" the speaker to any extent, and you don't hear that, you hear FR variation. It is complex but at the very heart of amp speaker interface. Dons chart is instructive as is referenced a the post before this one though the solid state amp would have more FR variations than his model showed IME. Keep in mind that modeling complex speaker loads is not easy and there are way many variables in a real world measurement, which means every model is a model unto itself, Dons are accurate to the model speaker he created so to speak.
A SET amps higher output impedance plays with the FR, as well as generating a more complex harmonic structure from the very design of the SET itself. The simple ideal goal would be to stop all power going out to the speaker at its resonance point, or reduce it as it approaches resonance, the SET amp reduces its output power, the solid state amp reduces voltage. SET tubbiness at low frequencies is about harmonic distortions and poor output transformer design, the better the output transformer, the less the harmonic distortion at low frequencies and the "tighter" the bass due to that alone.
Output impedance does not "grip" the speaker to any extent, and you don't hear that, you hear FR variation. It is complex but at the very heart of amp speaker interface. Dons chart is instructive as is referenced a the post before this one though the solid state amp would have more FR variations than his model showed IME. Keep in mind that modeling complex speaker loads is not easy and there are way many variables in a real world measurement, which means every model is a model unto itself, Dons are accurate to the model speaker he created so to speak.
Last edited: