Nadman12
Power delivered to headphones P=U^2/R, therefore in order to keep the same power/loudness, with higher impedance headphones, output voltage has to be also higher. Loudness becomes limited either by gain that is too low (tailored for common lower impedance earphones) or supply voltage (that is low in battery operated devices) - whatever occurs first.
Same exists for the speakers but in order to deliver more power (especially with SS amps) speakers are low impedance hence amp has to be able to deliver more current (since power is also P=I^2*R) and sometimes reaches amp's current limit.
Power delivered to headphones P=U^2/R, therefore in order to keep the same power/loudness, with higher impedance headphones, output voltage has to be also higher. Loudness becomes limited either by gain that is too low (tailored for common lower impedance earphones) or supply voltage (that is low in battery operated devices) - whatever occurs first.
Same exists for the speakers but in order to deliver more power (especially with SS amps) speakers are low impedance hence amp has to be able to deliver more current (since power is also P=I^2*R) and sometimes reaches amp's current limit.