ABSTRACT
Loudspeakers can be designed to exhibit almost constant impedance, although it is rarely done. Such loudspeakers can perform with remarkable consistency in spite of significant losses in the upstream signal path. Loudspeakers having nearly constant impedance can tolerate large wire losses, sacrificing only efficiency up to the resistance at which damping is affected. Powered loudspeakers have a big advantage: the power amplifiers needed to drive individual transducers can be much less ostentatious devices because the details of the load they drive are known and well defined. Most power amplifiers are designed to be constant-voltage sources so, unless an unfortunate interaction between amplifier and loudspeaker provokes limiting or protection. If the loudspeaker load is well behaved, well-designed inexpensive amplifiers can work just fine. The amount of the change in frequency response depends on the total voltage drop across the combined amplifier output impedance and wire resistance, meaning that minimizing both of these is desirable.
