Xsim is limited to 20khz, and REW 24khz. If my impedance graph is on a downward slope at those limits, I would assume that it continues downward. Is it a problem if the impedance drops to a very low value at ultra high frequencies? Would it eventually become a short circuit?
I found this random impedance graph online to use as an example:
I found this random impedance graph online to use as an example:
What happens depends on the parasitics of the speaker, for it to fall like that something is acting like a capacitance shunting across the inductance that causes the impedance rise a high frequency. You will always have the winding resistance, so I imagine the impedance would fall to that value and not become a short.
Could you show your crossover and I'll try to identify it.
Meanwhile, here's a previous discussion on letting this happen.
https://www.diyaudio.com/community/threads/problems-associated-with-a-capacitive-load.413083/
Meanwhile, here's a previous discussion on letting this happen.
https://www.diyaudio.com/community/threads/problems-associated-with-a-capacitive-load.413083/
Some amplifiers will oscillate if the load starts to look like a capacitor (90 degrees impedance angle and low impedance magnitude).
XSim4 will do sim up to 100kHz. https://www.libinst.com/FreeAppDownloads/
XSim4 will do sim up to 100kHz. https://www.libinst.com/FreeAppDownloads/
Electrostatics often drop to 1 ohm at 20khz, but I have never had an issue, even with Class D amps, which have increasing distortion as they approach the high extremities. So that would be a bad combination, in theory.
Never seen a short, or even Impedance that low with conventional drive units that are rated 4 ohms or higher.
Never seen a short, or even Impedance that low with conventional drive units that are rated 4 ohms or higher.
Thanks! That thread was very helpful. I’ll see if I can fix it myself.
I installed XSim4, and it is super helpful to see past 20khz. Thanks!
I did find a little glitch in the software though. When you open the tune box for a component, and click either open or short, the close button gets covered up. You can hit enter or click on the very edge of the close box which is visible, but something is going weird there. Might just be my old PC.
Class D designs usually have an inductive output filter, that would protect them.
The Class AB designs without an output inductor are those that make smoke into electrostatics.
Class d amps have a low pass filter right at the output, the last component being a beefy capacitor already. Capacitive load from a speaker, even an ESL, isn't likely to bother it