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Discussion Starter · #1 ·
I have a sono build that uses an Avalanche 18. The sonotube is 30" diameter and from bottom end cap to top endcap measures 54.5". The Length across the endcaps is 32".


Now I had my brother in law build this as I am terrible at DIY and really don'g understand it
So as of now I believe it's tuned to 16Hz. I'm wanting to lower the tuning to around 11Hz. Forgot to mention I am using an 8 inch port not flared (sonotube as well). The port now is 20". Curious what port length would be for 11-13hz tuning (flattest response)?


What lower tune can I go to and still have a good response curve?


The reason I'm wanting to lower the tuning is for Christmas he built me a sealed cabinet that I'm putting an Maelstrom in. I will be using both subs (I know some people frown upon different subs and getting them setup but what the hell)


Thanks for any help!!!
 

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Discussion Starter · #2 ·
"paging mr. herman, mr. herman you have a telephone call" (bump)
 

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Lv={ 8466.4R^2/(Vb)Fb^2} - 1.463R


Lv=port length

R= radius of port (half the diameter)

Vb=volume of box in cubic feet

Fb=tuning frequency
 

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Discussion Starter · #4 ·

Quote:
Originally Posted by mjg100 /forum/post/15573730


Lv={ 8466.4R^2/(Vb)Fb^2} - 1.463R


Lv=port length

R= radius of port (half the diameter)

Vb=volume of box in cubic feet

Fb=tuning frequency

This is what I don't understand?
 

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For your sub tuned to 11 Hz.

R=4

Vb=22.2826 CF

Fb=11


Lv=44.39" This is based on using 8" diameter port. (11Hz)

For 12 Hz Lv=36.37"

For 13 Hz Lv=30.12"


As far as flat curve, I do not know which tuning will provide the flattest response.
 

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Discussion Starter · #6 ·
cool thanks mjg100
 
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