If you mean the amplifier tests, I tried it both ways with a real speaker and dummy load. Results were the same. I post the dummy one. Without the amp, it is very hard to get a working setup due to termination.
Hi
@amirm, maybe I'm not following. A real speaker (or reactive dummy load), should present the amplifier output with a reactive load that can be characterized by LCR parameters. When there's a speaker cable in between the amp and the speaker (or dummy load), it adds additional LCR properties to that amplifier output.
The expected electrical measurement result of a sine sweep, in the setting of a cable + speaker, should be that of a flat line with
minor deviations in the measured FR that correspond to variations in the speaker's (or dummy load's) impedance curve. The deviations (particularly in the last octave) are often +/-0.5dB or less for ~12 gauge cable and shorter runs, such as those reported in Davis, JAES 1991;39:461-468, figure 12 below.
I think others on ASR have modeled the FR of a cable+speaker "circuit" using typical LCR values using simulation software, and achieved similar results.
This is why I'm confused as to why you're not also seeing these small FR deviations, when measuring the output of an audio amplifier with an actual loudspeaker load (with the cable of interest in between), because even in the case of a perfect cable (0 ohms, 0 uF, 0 mH), you should still see some deviation just from a loudspeaker load.