You can set the volume of each mode independently. Check to make sure the Bass is turned up.
Try reloading a bass preset.
Make sure your firmware is updated. It looks like Artiphon recently released a firmware update. Use the Orba 2 app on your PC/Mac to do the firmware update. You can force a firmware update by going into options in the desktop app (must be done in desktop, not mobile), and holding "Shift" while you click on "Firmware Version."
John Stuckmeyer