The iOne (and iTwo) are specifically designed to be used in a certain way. You cannot direct connect the interface the way you are suggesting.
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.
Once you do this, you'll need to grant permission to your iOS device to let the interface use your Microphone. If you don't do this, no audio will pass into the iOS device.
In that case, read this article on how to resolve this: