That is a different Kettle of fish. First of all, Apple came up with a slightly different set of resistors on the data pins (leaning that the data in and data

That is a different Kettle of fish. First of all, Apple came up with a slightly different set of resistors on the data pins (leaning that the data in and data out will read slightly different V) to signal to their devices that they could go above 1A draw while charging. The official charging spec says to put a resistor between the data pins (inside the charger to support detachable USB cables), or simply to short them with a blob of solder. Your JBL speakers are likely reacting as if it was plugged into a normal USB port. also keep in mind that the charging spec came about as China and EU wanted to deal with the piles of incompatible chargers that was going into landfills. Thus older USB ports max out at 5V 0.5A, as that was the spec back when USB 1.0 was launched. Also why some external HDDs come with a Y cable that draws power from two USB ports to get the motor spinning.