No higher than 32 Ohms for smartphone headphones. When using a good player or amplifier, it can be up to 100 Ohms. For stationary models you should coordinate the impedance with the amplifier power
More sensitive headphones will play louder than headphones with less sensitivity (with the same signal level and resistance)
The number of drivers in each headphone. However, quantity does not equal quality. Driver coordination, their configuration, correct crossover, sound bores affects the sound
Most of the headphones are dynamic but there are electrostatic, isodynamic, etc.
Model: Aurian Storm 2
Brand: Aurian
Cable length, m: 1.2
Model: Aurian Jungle
Model: Aurian Forest
Model: Aurian Ocean
Model: Aurian Canyon
Model: Aurian Skyline
Model: Aurian Hurricane
Model: Aurian Acid
Model: Aurian Sunset 2