how important is port legnth?

[302yota 10+ year member]

well i'm designing a box for 2 dd9512's......and i see that dd recomends a port legth of 22" per sub.....and the way my design sits now, i have 5.7cubes (before subs and brace disp.) at 34hz....with 94.25" of port area, with a port legth of 30".....how important is the port length in this situation (i know its about 14" short of what dd recommends)

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[ahole-ic]

well i'm designing a box for 2 dd9512's......and i see that dd recomends a port legth of 22" per sub.....and the way my design sits now, i have 5.7cubes (before subs and brace disp.) at 34hz....with 94.25" of port area, with a port legth of 30".....how important is the port length in this situation (i know its about 14" short of what dd recommends)

Port length is extremely important when it comes to getting tuned to the right freq. If you're already tuned right, then leave it alone.

 

[302yota 10+ year member]

yeah i knew that the port legth was the key factor in getting the desired tuning freq......but according to dd's site, they recommend a certain amount of port length, and with my design being a little short of what they recommend....i was concerned about that....because i've already acheived my desired tuning freq., but i dont want to have to add to the port legth

 

[RAM_Designs 5,000+ posts]

As long as you're tuned right, then don't mess with it. There's no "perfect" length for a port to be.

 

[302yota 10+ year member]

here is what the design looks like....i normally use L shaped ports but tuning was low enough, so i didnt feel the need to make it any longer

View attachment 26519125

 

[rosshimself13 10+ year member]

port length is not tied to the woofer it is derived from your enclosure size, port area, and desired tuning frequency.. wow that sounds smartassish but its truth