It’s sweat getting trapped in them. If it was condensation, that would occur almost immediately due to the difference in temperatures. However, after an hour or so they remain completely dry. They get droplets inside after 2-3 hours of continuous use. I can feel my ears and head getting warmer around the headphones.
That’s the thing, and as I’ve prattled on about before, certainly not new to me. With most closed-back headphones, when you get to the point where your ears feel sweaty during, or after use. There’s going to be some degree of moisture in the headphones.
It’s precisely why things like this (
randomly taken from Sony’s website for the WH-1000XM2 & WH-1000XM3) can be found on many manufacturers websites, or in some cases, the user manuals..
Refrain from:
using the headphones while you are sweaty. Sweat, wet hands or damp clothing can negatively affect the product: it can degrade the earpads, affect the USB charging slot and cause damage
And again, if you go look around HiFi/AV and headphone websites, you’ll see just how long condensation, sweat and moisture in general has been discussed for.
It’s far from new, but it is going to be a fairly common occurrence with closed-back metal cups. Which is exactly why Apple has this on their
website:
Your AirPods (1st and 2nd generation), charging case, AirPods Max and Smart Case aren't waterproof or water resistant, so be careful not to get moisture in any openings. If your AirPods come in contact with liquid, including sweat from a workout, wipe them down with a dry microfibre cloth. To dry the case, place it upside down with the lid open.
If your AirPods become damaged after they get wet, you can chat or talk with us to
order a replacement.