Compression driver protection when using active XO.

[Rob41]

I've read in a couple places that a capacitor must be used in series between the amp and the compression driver to protect the diaphragm when the amp is turned on and off.

How do I go about calculating the capacity and voltage needed? The driver being used is rated for 200w.

[BlueWizard]

What is the crossover frequency to the Compression Driver in the Active Crossover?

Just guessing, but if for example the Active Crossover Frequency were ...say... 2khz and the lower limit of the Compression Driver were say 500hz, then I would add a capacitor at about 1khz. Since the Capacitor represent a High-PASS filter, using a capacitor below the Crossover Frequency will assure that all the wanted frequencies will get through.

Keep in mind that is just a guess on my part. I'm sure others will have better suggestions.

I think it depends on the frequency of the Pulse you are trying to block. If you can get an oscilloscope, ideally one with memory or capture, and you can determine the pulse width of the pulse when the amps shut off. They you will have some sense of the frequency you need to block.

Just a few thoughts to get the discussion started.

Steve/BlueWizard

[Rob41]

Thanks Steve,

The minimum frequency of the horn is 600Hz and I'm shooting for crossing at 800Hz. This mid horn/driver will go up to about 3500-4500Khz. Sorry I can't get a closer approximation yet.

I wasn't aware it would be frequency dependent of the possible on/off thump but it makes sense.

-Rob