Here is the way to increase the ZX1's output power
1. Make sure the xLoud & Clear Phase was checked in the sound setting
2. Lower down the volume
3. Go to Setting / Apps / ALL / Sound enhancements / then push "Disable"
After disable the Sound enhancements, EQ won't work anymore.
You have to restart the ZX1 to make it work again.
Also works on F880 series...