KEF System Casual Analysis

[Nova]

@Nova : The 150-250hz dip is common in most vehicles. That's the frequency range of road noise.

I was parked when doing this measurement, but it may be related to what you have pointed out, because the wavelengths in this frequency range is very similar to the inner dimensions of a car. So my microphone could have been picking up a strong standing wave cancelation mode. These standing wave modes also contribute to road noise as they would amplify them in certain situations.

 

[Orchardbike]

All the JL Audio sub box are ported design but there's some that uses infinity baffle but ported design tends to require less power, probably why they went with it.

Having a ported enclosure allows the enclosure to be smaller than that required for a non ported enclosure.