flared ports - sx 15

[cblaze 10+ year member]

what size would you use,4.0 cubes of airspace after displacement,either 3,4 or 6 inch ones,or does it make a diff

Click to read more...

 

[JohnEJanowitz 10+ year member]

what size would you use,4.0 cubes of airspace after displacement,either 3,4 or 6 inch ones,or does it make a diff

The larger the port the less vent velocity. You get to a point when you surpass about 10m/s vent velocity where distortion becomes audible. At about 35m/s your vent velocity becomes turbulent and you can no longer push any more air through it. That is basically your brick wall for maximum output. Your port diameter to length ratio will always stay the same to get you the same tuning. Basically go with the largest diameter port you can before it becomes too long to fit in the enclosure for the tuning you want.

I have some papers by large loudspeaker manufacturers discussing port diameter. They found that to eliminate audible distortion you need to keep less than 10m/s velocity at all times. For most high excursion diameters this means a port diameter equal to the diameter of the woofer! Obviously this isn't practical in most cases. So going as large as you can is about the best advice to give.

John

 

[Lakota 5,000+ posts]

3 4" should be fine.

 

[cblaze 10+ year member]

i was thankin 2 4 inch ones,but if 3 is better ill try that