Question

I am using the AudioBox iTwo with an ipad Air2. Sound will come out of the ipad speakers or headphone jack but will not come out of the AudioBox headphone jack. I think that I have tried adjusting the mix knob, Main volume level and Headphone output level with no result.

Answer 1

iPad sound output is determine by the application used.  I do not think there is a "global" sound output device for everything on your iPad.  

Make sure you have things connected properly.

Here are the proper steps to connect your Audiobox iOne or iTwo.

1.) Using a supported official Apple power supply with your iPad, connect the USB cable that is included with your iOne or iTwo. 

2.) Plug the power supply brick into an electrical outlet.

3.) Plug the other free end of the USB cable to the USB "Power" port on the back panel of your Audiobox iOne or iTwo device. 

4.) Using an official Apple data cable (either 30 pin or lightning, which ever came with your iPad) connect the USB end to the "Device" port of your Audiobox iOne or iTwo. 

5.) With your iPad in sleep mode or awake and on the "Home" screen, plug the 30 pin or Lightning end of your data cable to your iPad.

Now you can launch any application on your iPad to enable usage with the Audiobox iOne or iTwo.