Box Tuning

[bigbassboi]

yes i would like to know

 

[photocrazy8 10+ year member]

any one?

 

[matt_martin87 10+ year member]

So where does port size in terms of sq" come into play?

Explain

 

[Trixter 10+ year member]

not to make anyone sound like an idiot, but i'm going to dumb this down for everyone...

the sq" of the port is simply the area of the opening

-for a slot/square port it is the height x the width

-for round ports it is radius squared x PI (3.14)

the sq" is important because too little and you will get wind toubulance which can cause distortion. too much port area (depending on the box) can cause the sub to reach over excursion (like being in free air).

for round ports i use...

6"-8" driver - 3" wide port

8"-10" driver - 4" wide port

10"-12" driver - 5" wide port

12"-15" driver - 6" wide port

these numbers can be used to figure out slot ports as well...

example: pair of 12's: (2.5 x 2.5) X 3.14 = 19.6 (we'll just round to 20) then 20 x 2 = 40sq" of port.

now, depending on the box volume and desired tuning freq., will determine the port length.

the larger the port area, the longer it will need to be to achive a given freq., the less port area, the shorter it needs to be. you could, in theory, have a small box and tune it really low (16hz or what ever) with only using a 2" round port that would only have to be 8" long. but because of the tourbulance, it will be distorted and possibly even whistle. so, the right combination of port area, box volume, and desired freq. will determine the port length.

if i confused anyone even more...oh well, you asked.

 

[truckstoy 10+ year member]

not to make anyone sound like an idiot, but i'm going to dumb this down for everyone...
the sq" of the port is simply the area of the opening

-for a slot/square port it is the height x the width

-for round ports it is radius squared x PI (3.14)

the sq" is important because too little and you will get wind toubulance which can cause distortion. too much port area (depending on the box) can cause the sub to reach over excursion (like being in free air).

for round ports i use...

6"-8" driver - 3" wide port

8"-10" driver - 4" wide port

10"-12" driver - 5" wide port

12"-15" driver - 6" wide port

these numbers can be used to figure out slot ports as well...

example: pair of 12's: (2.5 x 2.5) X 3.14 = 19.6 (we'll just round to 20) then 20 x 2 = 40sq" of port.

now, depending on the box volume and desired tuning freq., will determine the port length.

the larger the port area, the longer it will need to be to achive a given freq., the less port area, the shorter it needs to be. you could, in theory, have a small box and tune it really low (16hz or what ever) with only using a 2" round port that would only have to be 8" long. but because of the tourbulance, it will be distorted and possibly even whistle. so, the right combination of port area, box volume, and desired freq. will determine the port length.

if i confused anyone even more...oh well, you asked.

very well said //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[matt_martin87 10+ year member]

Now I understand. sq"=Square inches. I was confused by the way it was written.

 

[slikrider20 10+ year member]

martin, what r u doing on here during schoo?

 

[matt_martin87 10+ year member]

Whoa holt. I could ask you the same question. We're in school, there's no time for car audio here.

 

[lionel2 10+ year member]

I have my subs tuned to 27hz it hits hard and low..just doing what is recommended by JL