subwoofer rms with ports

What exactly determines whether or how much a subwoofer's RMS power handling will decrease with ported enclosures? Port area, length, or something completely different?

Thanks!

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I can't hear you!

Who says the power handling decreases with a ported enclosure?

Above the tuning frequency, the MECHANICAL power handling can be equal to or even above the electrical power handling. Any failure manifested at this point would be electrical. Below the tuning, there are very FEW enclosures that will allow a mechanical power handling that is equal to the electrical power handling.

The specified power rating on a woofer is the ELECTRICAL power handling, and it does not change, no matter the enclosure.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Alright because im comparing to a sealed enclosure where you'll yield more SPL with more power to or above the subwoofers RMS rating. and with many SPL subwoofer manuals they'll have multiple Ported enclosure recommendations with a range of Power Handling for the subwoofer. Do you think is suggested more for the Mechanical power for the subwoofer so consumers do not over extend the suspension?

And if that is the Case, which is the most important Variable of the Port they use to measure the range of power for the subwoofer in that specific box?

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I can't hear you!