Sealing off my 28hz box??

[gmoney69 10+ year member]

OK so i want my box tuned lower/get louder. right now its tuned to 28hz and its just 2 low for me..

heres the box from the original thread.

http://forums.caraudio.com/vb/showthread.php?t=108260

Is there any way of making this box for SPL? iv heard of sealing it off or cutting the port down inside but idk? any responses will help! thanks

Click to read more...

 

[j3bus2k3 5,000+ posts]

That link is for your HU post...

 

[gmoney69 10+ year member]

oops there fixed

 

[mazdakid 5,000+ posts]

sealing it off probably isnt going to make it louder, try to just cut like an inch or so off from the port at a time until its how you like it

 

[JimJ 5,000+ posts]

OK so i want my box tuned lower/get louder. right now its tuned to 28hz and its just 2 low for me..

You want it tuned higher...

 

[gmoney69 10+ year member]

yes..

 

[swimfreak26 10+ year member]

Tuning higher just requires shortening the port length. The problem is that you then have to take into account the extra volume you create by freeing up the space that was used by the portion of the port you cut away.

Port length = ((Av*(1.84*10^8))/(Bv*1728*(F/0.159)^2))-(0.823*SQRT(Av))

Where Av is the cross sectional port area in square inches, Bv is the box volume (net) in cubic feet, and F is the tuning frequency.

EDIT: If you're tuned at 28Hz now, you may want to try something around 35Hz to notice a difference. I personally don't like going higher than that, but up to 40 you won't sound horrible in a daily driver.