No in game volume

There are 2 volume settings for your Turtle Beaches.

Game volume and Game to Chat volume.

Make sure your Game to Chat volume is turned up high and then your standard Game Volume should come through loud and clear.

The Volume + and - raises and lowers ALL volume. The Game and Chat buttons adjust the mix between the two. That means, repeatedly press the Game button to raise the Game volume, in relation to chat. Press the chat button repeatedly to raise the chat volume.
This is completely independent of the volume.

This of it like a mixing board. You have a slider for the Game track, a slider for the Chat track, and a Master volume slider.

While looking at the Microsoft chat adapter you will see five buttons from the left to the right. Game Volume button, Chat Volume button, Mute button, Volume up button and Volume down button. Pressing the button with the little controller symbol will let
you control the game sound volume. The button with the little person symbol will let you control the chat volume. To turn the chat or game sound up or down press the corresponding button and then use the volume up/down to tune the sound to your liking.

I use turtle beach headphones with the adapter. What I do is turn chat volume up with adapter, then I use the volume control on the cable connecting headset to controller to control chat volume while controlling game volume with volume control on the headset.

I like my TB X11. Game Volume. Chat Volume. Done.