Split Topic: Impedance mismatch... (BD-Design)

by madprofessor , 27777 Ganderkesee, Germany, Wednesday, January 20, 2010, 17:32 (5232 days ago) @ Bert

Hallo !
I did myself a lot of measurements on impedances.
Important thing ist to measure in the frequency range of interest - I´d suggest 5 Hz - 100kHz, and to measure with an vector analyzer and/ or TDR.
My results are, that the average RCA connector ( except WBT Nextgen, which are about 75 Ohms) has 23 Ohms impedance.
High End audio cables vary from as low as 19 Ohms to 120 Ohms.
Technically that means, if you dont terminate that cables with their specific impedance, you get reflections back to the source. The higher the source resistance, so worse it gets.
These reflections means of course also variations in dynamic frequency response.
For me that is reason enough, to match everything to the impedance, given by unchangeable parameters, like interconnects. Also it means of course to use very low impedances. Anything below 50 Ohms is quite good.
To build output stages, that can drive under dynamic conditions a low impedance load is not quite easy.
The standard measurements for impedance don´t mean anything, if not paralell the distorion am intermodulation is measured and low.

Best regards
Stephan