Merging 2 audio sources into one pair of headphones

[zoog18]

So I have an Xbox one and for various reasons I want to use an iPad for voice chat. I own the Xbox one stereo headphone adapter that you connect to the controller, and what I did was connect a Y splitter cable to that and then connect my headphones into one end and the iPad into the other. It's works perfectly, however I've heard this setup can damage one or both of the audio sources. Is that true? (Neither is very loud btw)

https://m.imgur.com/a/r9Bif

 

[jsmithepa]

I've heard this setup can damage one or both of the audio sources. Is that true?

Correct.

The proper way to do this is to route your sources through a box called a MIXER.

 

[zoog18]

I've heard this setup can damage one or both of the audio sources. Is that true?

Correct.

The proper way to do this is to route your sources through a box called a MIXER.

Could I use the astro mixamp pro i have for that? Also, I used the setup I posted for only about a 30 minute period, how do I know if I damaged anything?