I made an accidental discovery today.
For several months I’ve used Moondrop Kanas Pro IEMs for mobile listening and always sitting up. Today – for the first time ever – I used them while laying down.
They are slightly undersized when resting in my ears; they lost most bass and became bright and thin. When sitting upright the bass tends to be full and even boomy, so I use them with the factory silicone tips for a bit of venting. Gravity holds them in close and tight. However, when laying down they were weak even with my fingers holding them in place.
Everyone knows that IEMs are tip dependent, but now I’m wondering if there’s been any research on orientation dependence. The Kanas Pro allow about 20-30 degrees of rotational adjustment in my ears, so the bass apparently follows from allowing the top to fall forward.
Just another consideration for IEM reviews and differences of opinion.