If you want to know all ins and outs of wired headphones then you are in the right place. I am going to show you the difference between Audio-Technica ATH-M50x vs Koss Pro4S both of which can be used only with an audio cable. These devices are closed-back and have an over-ear design.
Let's start with comparing their impedance. In the case with Audio-Technica ATH-M50x, it is 38 Ohm, while Koss Pro4S has 35 Ohm. Speaking of frequency response, the first appliance has a range of 15 Hz - 28 kHz, while the second one works in a range between 10 Hz - 25 kHz. Their sensitivity is identical — 99 dB.
The sound signature of Audio-Technica ATH-M50x is even and there is virtually no distortion. The bass is very rich and low but not overdone. Although the high end is not overly crisp, it is very detailed. Overall, it provides a balanced rich sound with good separation and clarity.
Vocals that you get with Koss Pro4S have a velvety texture and overdrive guitar has a lovely presence, balanced by the lower-midrange fullness. The midrange is warm and full.
The headphones made by Audio-Technica are pretty heavy compared to the other device, as its weight is 285 g, whilst Koss Pro4S weighs only 180 g. However, the model ATH-M50x is foldable which is a big advantage. Both of the considered appliances have an adjustable headband and come with a ballistic nylon carrying case.
The wire that you get with Audio-Technica ATH-M50x is 300 cm and it might be too long for using the device while walking. But the coil cable gives you freedom of movement without a long cable hanging on the floor. The length of the detachable audio cable that Koss Pro4S has is 140 cm. The considered headphones do not have a built-in microphone and buttons for control.