4 responses Add your response
It needn’t be one or the other; bench tests can aid the consumer in narrowing his search for, say, a synergistic loudspeaker/amplifier pairing. When a John Atkinson bench test of a power amplifier reveals the amp to have a very high source impedance (not uncommon in tube designs), and a speaker to have a wildly-varying impedance curve, the consumer will know there is a good chance the pairing of the two will be unsuccessful; the speaker may not sound as the designer intends it to. Without the bench tests revealing the amp’s and speaker’s impedance characteristics, the consumer will not know where to lay the blame for the sound resulting from the pairing. With the test results, the consumer will be better informed about how the speaker and/or amplifier will interact with other pairing candidates, at least as far as matters of impedance are concerned. Good information to have, imo.
MG, I was first apprised of the amp/speaker impedance interaction when looking for an amplifier for the original Quad ESL, which has an insane impedance curve (from around 1 ohm to 30!). When an amp with a high source impedance is partnered with the Quad, the resulting frequency response will closely resemble the impedance curve of the amp. Not good!