Originally Posted by sor
You realize you’re talking about tweeters, at 10khz, right? I’ve never heard of anyone worrying that they’re going to “lose control” of a stiff, tiny little piece of film vibrating over micrometers.
I’ve always been under the impression that the importance of damping is relative to the mass of the speaker driver - if you have a giant 18” subwoofer damping is fairly important to help control that mass. A tweeter on the other hand will have no problem being damped by just its own film stiffness.
Look, I don’t think you’re wrong about your RLC calculations, as others have pointed out it IS possible to calculate a tiny but measurable filtering effect due to cable reactivity. However, I think the problem is in understanding the application and relevance.
Like I said, the reactance of the cable ( inductance) will react with the speaker reactance( speaker is NOT pure resistance) and can form a complex circuit that cause phase shift at higher frequency. This is like moving the tweeter back and fore from the listen distance. You should know how sensitive the hearing to the speaker distance.
People want to think DF is for bass only, but that's wrong, low damping factor can cause the signal to lose flatness at the speaker end even though it is flat at output of the amp. I don't look at just controlling the speaker, I look at it as voltage divider of complex impedance that change the gain and phase at the speaker input due to the divider effect between the source ( output impedance of the amp plus cable reactance) to the load ( reactance of the speakers with crossover inside the cabinet)
For reactive element inside the speakers, you can even form a low Q tank circuit. Draw out the circuit of the speakers, you can see it's far from being resistive.
BTW, don't think of the speaker in term of "speaker with a moving coil and magnet. The amp is actually driving the crossover, the crossover drives the speakers inside the cabinet. The crossover is the trouble maker. Each has it's LC tank circuit, they have their resonance peak. The better the speaker, the better the components used in the crossover and the lower the loss the crossover network. What does that means.........Lower loss meaning Q is higher, Q is higher meaning the peak and the valley of the impedance is a lot sharper. This change of impedance intereact with the cable inductance and further affect the gain and phase.
Speaker cable is very different animal from those RCA preamp cables, for preamp, the input using are resistive and in 20,000ohm range, all the inductance and all become a non issue. But speaker impedance is in 4 to 8 ohm. Some hard to drive speakers can have impedance dip down to 2ohm!!! That's where the loss of the cable really matter.
You sound like you know basic RLC calculation. Try model the speaker ( 3 way) and 3 RLC tank circuits at different frequency, then add the cable inductance and see the voltage divider effect and look at the gain and phase at the speaker input end.