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tooshort_128
01-29-2009, 12:52 PM
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.

NewAgeKing
01-29-2009, 12:54 PM
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
01-29-2009, 12:59 PM
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
01-29-2009, 01:02 PM
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
01-29-2009, 01:07 PM
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
01-29-2009, 01:11 PM
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
01-29-2009, 01:11 PM
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
01-29-2009, 01:13 PM
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
01-29-2009, 01:15 PM
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
01-29-2009, 01:18 PM
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
01-29-2009, 01:20 PM
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
01-29-2009, 01:21 PM
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
01-29-2009, 01:22 PM
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
01-29-2009, 01:28 PM
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
01-29-2009, 01:30 PM
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.

netzero
01-29-2009, 01:45 PM
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?

It's better to go with less larger ports to reduce the surface area, reducing noise. Like tommyk said, try three 6", but if they end up too big, two 6" would work just fine.

tommyk90
01-29-2009, 01:48 PM
It's better to go with less larger ports to reduce the surface area, reducing noise. Like tommyk said, try three 6", but if they end up too big, two 6" would work just fine.

x2

2 6's is more port area than 4 4's anyways. I recommended 3 6's because that's what we used on one of my teammates boxes with two MT 15's and it wangs.

SSS 18734
01-29-2009, 01:49 PM
You can also turn the port inside the box using pipe elbows.

tooshort_128
01-29-2009, 01:50 PM
I don't have much room to work with. That's why I'm thinking round flared port as opposed to slot port as the slot would displace a lot more space. I think I may try it out with 1 4" and see what happens.

netzero
01-29-2009, 01:54 PM
I don't have much room to work with. That's why I'm thinking round flared port as opposed to slot port as the slot would displace a lot more space. I think I may try it out with 1 4" and see what happens.

Ya 2 cubes, with a 4" aero will be fine on space constraints. Just get either a 90* or if you can a 45* elbow and use that.

tooshort_128
01-29-2009, 02:32 PM
what would be a safe clearance between the back of the box and the end of the port? 2"? 4"?