Does bridging an amp would halve the impedance of the speakers?
Impedance is a characteristic of the speakers. The speakers don’t give a flip how the amp is configured: they have a given impedance curve, and that’s that. It should be clear that when you bridge an amp, you are changing *the amp*. The speaker’s impedance is *not* a function of the amp, but the amp’s tolerance to a given impedance depends completely on the way the amp is configured. If you’ll remember from section 4, an amp bridged into a given impedance draws twice as much current as it would if it were driving two separate channels, each at that impedance. So, a four ohm speaker stays a four ohm speaker, if it’s hooked to one channel, a bridged channel, a toaster, or the wall socket. But, it is more stressful for the amp to drive any impedance bridged than unbridged. So, why do people talk about the impedance halving? Well, it’s a simple model that isn’t correct but is easy to explain to people who don’t know what’s really going on. It goes like this: When you bridge the amp, each c
