Load, impedance and 'load impedance'

[Layla Nahar]

I'm under the impression that "load" and "impedance" are synonymous.

Can anyone explain this statement: (context - speaker hookup, parallel connections)

The load placed on the amplifyer is increased with each additional speaker. As the load is increased (impedance lowered), the amplifier puts out more power. [text continues]: If the load is increased too much, the amplifier will create too much power for itself and will overheat


Can anyone explain this?

Thanks
LN

 

[DonF]

Disclaimer: I'm no electrical engineer.

It's kinda like plugging in too many appliances into one outlet in your kitchen. Each appliance draws a certain amount of electricity out of the outlet. At some point, the total draw is more than the wires going from the circuit breaker box to the outlet can carry -- and, if everything works right, a circuit breaker trips, saving you the embarrasment of an impromptu visit from the local fire department.

Increasing the load (by plugging in and turning on additional appliances) reduces the impedance on the circuit, because there are more paths for the electricity to take. (Impedance is opposition to the flow of power in an electrical circuit.) Less impedance = more power. More power = more heat (through a given size of wire).

The circuits inside your amplifier are designed to handle a certain amount of power, and no more. Unless they have some kind of protection (like the circuit breakers protecting the wiring in your house), drawing too much power from the amp will fry something inside the amp sooner or later.

Hope that helps. (Any EE's out there, feel free to enlighten me if I've gotten anything way wrong.)