Quick question about RC and LC pass filters

[TheBaconWizard]

Hi there,

When calculating the values for these simple circuits, should one take into account the resistance and impedance of the speaker itself as well as the components that will be added to achieve a certain cut-off frequency?

[tatus1969]

as most drivers are designed to be driven by the low ohmic output voltage of an amplifier, i would take the complex impedance curve of them into account when designing a filter. my high end 2way speakers have a crossover board with literally dozens of parts.

[danadak]

The load for sure will effect circuit response, unless you filter in the signal
path, buffer, and drive speaker with buffer output. Of course the latter
requires amp for each driven component.


Regards, Dana.

[TheBaconWizard]

Ok; I'm obviously not making the simplicity of my knowledge and the circuit clear enough. I'm a dumbass, so I have posted in the beginner fourm.

Given an RC high-pass filter supplying an 8 ohm speaker, should I account for the fact that the speaker itself has 8 ohms of resistance in addition to the resistor I would normally use with the capacitor in order to calculate cut-off frequency?

I assume the same will be true of impedance, in a low-pass filter.

To put it another way: when calculating the values for resistor and capacitor in a simple RC high-pass filter, should I cater for the fact that the speaker has 8ohms resistance as well? Ie, the resister should be 8 ohms less, if it matters.

Alternatively, in an LC low-lass circuit, should I measure and then account for the speaker's impedance when calculating what resistor and inductor will be required for a given cut-off?

[tatus1969]

can you measure their impedances? means, do you have a lcr meter?