Originally Posted by Caution
Hasn't it been proved time and time again that cables will produce different waves due to the material used? The results seem pretty obvious to me...
Measurments on cables are rare, except in radiofrequencies. Do you know of any measurment made in audio frequencies on interconnects ?
Originally Posted by MoodySteve
Some would say that testing cables using clean signals such as sine waves doesn't accurately simulate their response to the considerably more complex waveforms that music produces.
It does, because cables behave linearly from an algebric point of view (their THD and IMD are strictly null, and their noise is negligible). Therefore it is relevant to assume that a complex signal is a sum of simple ones.
Originally Posted by myinitialsaredac
No one has input on the procedures/variables/constants?
You can find here some measurments done on a set of various interconnects :homecinema-fr.com • Afficher le sujet - RÃ©sultats du test en aveugle - cÃ¢bles de modulation
Get the file at the bottom of the first post. This can help you figuring out the magnitude order of the expected differences.
You plan to use triangle and square waves. This raises the question of the frequency band studied. Should the study be restricted to audio frequencies (20 to 20 kHz) ? In this case, triangle and square wave, whose frequency range are infinite, should not apply.
Beware that a square wave of 10 kHz is nothing else than a sine wave of 10 kHz, plus a sine wave of 30 kHz, plus a sine wave of 50 kHz, then 70 kHz, 90 kHz etc.
Restrict the square wave into the audio band, and all that remains is a pure 10 kHz sine wave !
If you restrict yourself in audio frequencies, then the time accuracy of the oscilloscope becomes a minor factor, and you can get much more accurate recordings from a computer soundcard than from an oscilloscope (around 17 bits of accuracy, given their signal-to-noise ratio).
The attenuation of the interconnects are strongly dependant on the impedance of the source and of the load. The normalized source impedance in hifi is 470 Ohms, and the normalized load impedance in 47 kOhms. Oscilloscopes should have a higher impedance, resulting in less distorsion.
Measuring time-domain reflexions seems irrelevant, since they will be defined by your RCA/BNC adapters, impulse and signal generators, and oscilloscope, and will have nothing to do with the reflexions in a normal setup.
Anyway, the expected difference are extremely small. The highest chances to get a measurable difference is using very long cables (get a 5 or 10 meters extension cord for interconnects, for example), or analysing very high frequencies (more than a MHz), where the attenuation should be more important.
Given your setup, the square wave meets this condition, as it features high frequecies harmonics, far outside the audio band.
Good luck, and keep us informed.