Can I connect two headsets to the old iPhone (6s or older)? Will they play both?
To old models of iPhone, which have both a Lightning connector and a 3.5 mm connector, you can connect two headsets to iPod Touch and iPad tablets simultaneously.
When you connect one pair of headphones on Lightnind, and the second on Mini Jack (3.5 mm), nothing terrible will happen. This connection is possible and does not contradict the rules of gadget operation.
Unfortunately, both headsets will not work simultaneously.
iOS will give preference to the last connected headset. For example, if you first connected headphones to 3.5 mm, and then to Lightning, then the sound will be played on the Lightning headset.
If you want to connect two headsets to the iPhone for simultaneous listening, use the adapters. Now the choice of such accessories is quite extensive.