In fact, you can get a fairly good one for under $20. The hardware you need to buy is called an ‘Audio splitter’, and it’s not expensive. If you need to connect two headphones to a single 3.5mm jack on either a Macbook or a Windows/Linux PC, you’re going to have to buy hardware to do the job. When combo jacks began getting popular, some laptops came with two combo jacks that allowed users to connect two different sets of headphones to a laptop.
Early laptops used to have a separate jack for headphones and mics.
