Round Precision Port diameter?

[tooshort_128 10+ year member]

Would a single 4" Precision Port be okay in a 2 cube enclosure be okay or would it be too much port noise? Box will be tuned to 30Hz.

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[NewAgeKing 5,000+ posts]

Single 4" aero port at 17 inches long would be good. I have mine 2.5 inches from my back wall in the box but some recomend having it 4" away from the back. For the little testing i did i have zero port noise but i wont know for sure until i get some good air moving.

 

[tooshort_128 10+ year member]

I probably won't have enough room for 17". The calc says about 16 inches but my box won't be deep enough to have clearance between the port and the back of my box. Is there a way to turn the port inside the box?

 

[NewAgeKing 5,000+ posts]

I probably won't have enough room for 17". The calc says about 16 inches but my box won't be deep enough to have clearance between the port and the back of my box. Is there a way to turn the port inside the box?

You could maybe see what you can use for shorter ports. You can run a single 3" port at 9.5 inches. Just remember that it will be longer because the flares add length but they dont count for the length you need to get your tuning.

 

[tooshort_128 10+ year member]

a single 3" at a shorter length would be optimal but would that give me port noise? Aren't the precision ports supposed to help eliminate port noise?

 

[tommyk90 5,000+ posts]

I would use at minimum one 4" port for a single 12".

Two would be more optimal, but the length will increase quite a bit.

 

[NewAgeKing 5,000+ posts]

a single 3" at a shorter length would be optimal but would that give me port noise? Aren't the precision ports supposed to help eliminate port noise?

I dont think there would be any issues with a single 3" port at that length using flares but im not positive.

 

[NewAgeKing 5,000+ posts]

I would use at minimum one 4" port for a single 12".
Two would be more optimal, but the length will increase quite a bit.

I agree but if he cant fit that one in his box then what would be the next option you would suggest?

 

[tommyk90 5,000+ posts]

I agree but if he cant fit that one in his box then what would be the next option you would suggest?

No other option really besides a slot port.

He could probably get away with one 4" port, but I wouldn't do it.

 

[NewAgeKing 5,000+ posts]

No other option really besides a slot port.
He could probably get away with one 4" port, but I wouldn't do it.

Yeah he could but then he will lose some more space inside using a slot then ports. He says 2 cubes but i dont know if thats net or if his goal is to get 2 cubes after displacments. He could also use two 2" ports at 9" long wich would maybe be like using a single 4" instead of the 3" one i suggested.

 

[tommyk90 5,000+ posts]

Yeah he could but then he will lose some more space inside using a slot then ports. He says 2 cubes but i dont know if thats net or if his goal is to get 2 cubes after displacments. He could also use two 2" ports at 9" long wich would maybe be like using a single 4" instead of the 3" one i suggested.

Two 2" ports is half the port area of one 4", which is why they only have to be 9" long.

 

[NewAgeKing 5,000+ posts]

Two 2" ports is less than half the port area of one 4", which is why they only have to be 9" long.

Interesting to know. What are the dimentions you have to work with OP? You could try to use some rings on the outside to extend the ports out further so they will fit. It may look a little goofy though.

 

[netzero 10+ year member]

Yeah he could but then he will lose some more space inside using a slot then ports. He says 2 cubes but i dont know if thats net or if his goal is to get 2 cubes after displacments. He could also use two 2" ports at 9" long wich would maybe be like using a single 4" instead of the 3" one i suggested.

Two 2" ports would be half the area of one 4" port... You can use a 90 degree elbow from Home depot or lowes to bend it. I would say go with the 4" port, you'll be glad you did. 3" would work, but you'll be holding your sub back.

 

[01 S 10 10+ year member]

ive heard that technically you only need roughly half the port area using aero ports compared to slot ports.. 1 4" should be ok then?? tommyk, what would you suggest for 6cf with 2 15"s? (nightshades) 4 4"s for daily?

 

[tommyk90 5,000+ posts]

ive heard that technically you only need roughly half the port area using aero ports compared to slot ports.. 1 4" should be ok then?? tommyk, what would you suggest for 6cf with 2 15"s? (nightshades) 4 4"s for daily?

What kind of power? I would try 3 6's instead.