Yeah, how the headphone output is implemented on laptops and similar devices is not clearly defined. On some equipment the headphone jack is essentially parall

Yeah, how the headphone output is implemented on laptops and similar devices is not clearly defined. On some equipment the headphone jack is essentially paralleled with the speaker feed and configured to switch out the speakers when the headphones are plugged in. In this configuration the level for normal headphones use is way too high. If the volume is still set to the level that's normally OK for the speakers when the headphones' plug is inserted then that level is likely to be sufficiently high to damage the headphones (and one's hearing). The opposite also happens, some weeks ago I got fed up with the really crappy sound of my Samsung TV so I thought I'd plug in some better quality speakers as I've done previously with other TV sets only to find that it was genuine headphone outlet, the volume was so low I could hear almost nothing. It's a nuisance that manufacturers don't make that distinction clear with better labelling.