Home › Forums › General Discussion & Questions › Not B&O related but technical: Amps, speakers and impedance › Reply To: Not B&O related but technical: Amps, speakers and impedance
Thinking about this as water running through pipe helped me pass some physics and EE classes. Think of the circuit as a pipe, and the resistance as the diameter of the pipe. The higher the resistance, the smaller the diameter of the pipe. It takes more water flow (amps) to achieve the same pressure (voltage) of the water in a big pipe (4 Ohms) vs. a small pipe (8 Ohms). Therefore, the pump (the amp) has to work harder to achieve the same pressure (voltage).
If you prefer math, it’s because Voltage (V) =current (I) * resistance (R) (Ohms law). Of course, with a speaker, it’s a lot more complicated because of the dynamics of reproducing sound, but at any instant in time, Ohms law holds true (more or less). I believe this is what Mr 10% was getting at. Because of the complexity of dynamic circuit behavior, Ohms law is only an approximation so speaker specifications like impedance are also an approximation, and as an approximation can be influenced by “marketing” spin.