How severe is port resonance in 4th order bandpass?

[wonderfulaudio]

Hi,

I would like to discuss a couple points regarding the port in case of 4th order bandpass subwoofer:-

1) How severe is the port resonance? The simulation shows a dip at about 180Hz, the reason why I ask is that I've read that simulation exaggerates it, it may actually not be such a deep null.
2) Can this slope before the first port resonance null (between 100Hz and 180Hz) be used as an acoustic crossover, the second peak is at 363Hz, I could always use a crossover (2nd order low pass ) at 200Hz only for that.
3) Is that peak at 363 Hz also exaggerated in simulation?

Warm Regards,
WonderfulAudio

 

[AllenB]

https://www.diyaudio.com/community/...sonance-absorbers-and-port-geometries.388264/

 

[Freedom666]

here a measurement of a Visaton 17cm bass in 4th order. Without crossover.

Looks good, but at least 6db filter needed for the bass


https://www.donhighend.de/?page_id=8974

 

[Freedom666]

the vented cavity of the bass is damped on the walls.

This helps a lot!

 

[Booger weldz]

 

[Booger weldz]

I’m dumb…. Sorry. I saw ‘band pass’ and ‘ port resonace’ and got excited and posted my 6 th order parallel(not 4th….)

The full wave length gap before all the 1/4 wave junk as a crossover region is always intersting to me as well .

I did notice 345.6/meter/second /192hz is the full wave length of the entire enclosure (front to back of driver) of 180 cm?





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