Port Length/size Calculations, Please Check.

[cmrs2k]

Greetings. I have been a member of this forum for a little while. I am very new to a lot of this. I have built a few sealed boxes, but vented enclosures are very new and mysterious to me. I have designed an enclosure and calculated the port dimensions, but I would like some advice and a check over what I have found. I could be right on, or I could be so far off that I won't even be able to find my way back to this forum again. Here are the details:

Box volume is 11 cubic foot after sub displacement. I am hoping to tune to 40HZ.

I have figured for three options for the port.

1 port 6" high, 20" wide, and 9.33" deep.

1 port 6" high, 26" wide, and 13.58 deep.

1 port 6" high, 28" wide, and 15.03 deep.

I do not know if they are right. The port calculator that I used showed that all 3 of these and many others would do it. If they are right or not, what would be the difference? Would there be an advantage to using one over the others if they all will tune to the same frequency? I appreciate any advice that any one is willing to give. Thanks.

[andym85]

first port: 120sq" tuned to 41hz, net box volume is 10.52cft

second port: 156sq" tuned to about 42.4hz, net box volume is 9.77cft

third port: 168sq" tuned to about 43.1hz, net box volume is 9.47cft

if you are going for all out spl then i would choose the third port because it has the most port area and is tuned the highest, if this if for daily driving then i wouldnt choose any of them becuase they are tuned too high for my tastes...

[cmrs2k]

first port: 120sq" tuned to 41hz, net box volume is 10.52cft

second port: 156sq" tuned to about 42.4hz, net box volume is 9.77cft

third port: 168sq" tuned to about 43.1hz, net box volume is 9.47cft

if you are going for all out spl then i would choose the third port because it has the most port area and is tuned the highest, if this if for daily driving then i wouldnt choose any of them becuase they are tuned too high for my tastes...

Thank you for your help. The information is much appreciated. What formulas or calculator did you use to figure those up? For daily driving, what would you tune to? Thanks again.

[andym85]

no prob. i made my own excel program to figure everything out and posted it in another topic... http://www.stevemeadedesigns.com/board/ind...?showtopic=4802

for daily i would tune to like 30-36, im tuned to 28 which might be too low, but i love it. 32-34hz is usually a good frequency.