I don't know what your "speaker set" actually is or how it's designed to work, but AC and DC are two totally different things.
Also, 1A of current is probably more than a 9V battery can supply... I am not sure what the internal resistance is but I would be surprised if a 9V can support a...
It's been many years since I was doing physics in college, and I am beyond rusty... and I could use a little help.
I am trying to fabricate a little hobby project involving a motorized platform (like a radio controlled car) that I can move at somewhat precise speeds and program relatively...
Just make sure the resistor has suitable power rating - in the above scenario, the resistor is dropping 6 volts at 0.8A, which is 4.8 watts. I'd use at least a 10 watt resistor in that case, and that is going to be a LOT of heat... it would need mounted on a pretty beefy heatsink. The LED will...