HiFiMan HE400se

The cheapest way onto a real planar-magnetic driver, and the headphone that taught a generation what planar bass control means: low end that stops and starts on command instead of blooming over everything.

It is a first serious open-back for students, desk listeners and the planar-curious. At 25 Ω and 91 dB it will play from a phone at moderate volume, but it scales with power — plug it into a proper desktop amp and it audibly wakes up.

Know before buying: fully open, so it leaks both ways; 390 g, so the fit deserves a minute of adjustment; and the stock pads are serviceable rather than plush.