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Slot Port vs. Round Port

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what is the difference between the two? sub would be a 12" FI BL in a 2.5 CuFt box with about 1200 watts. would i save room with the round port? i forgot the tuning, 33Hz

Edited by WhatsCS

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i need help.

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From my understanding they are identical, but it is easier to get more port area with a slot port. You're going to need between 30-40 square inches of port area using the rule of 12-16 square inches of port area per cub of volume. Although, if you use a aero port, you can use 50%-75% of the recommended port area. This is because aero ports are flared, and the flares reduce air turbulence in the port. So you can use less port area (which increases vent air speed) but since aero ports reduce air turbulence, the increase in air speed will not result in port noise. The rule of 12-16 square inches of port area is actually a lot of port area. This large amount of port area is needed to reduce air speed in the port so you don't have port noise. Since aero ports reduce air speed in the port (compared to a slot port with the same port area as the aero port), you can use less port area with an aero port. So in your case 23-30 square inches of port area with an aero port (calculation: 75% of 30 and 40) so a 6" diameter areo port with according length for your tuning.

Also, using less port area with the aero port will yield less volume displaced by the port than a regular slot port. So in the end you will need a smaller enclosure using an aero port.

Edited by Im Hung N ur Not

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Hmm, ok. i was trying to see if i could save room, but it seems like i wont, due to the amount i would need. or maybe im wrong, i dont know.... i guess ill stick with vent for now.

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Just do slot :)

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Just do slot :)

yeah....

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Just do slot :)

yeah....

You mean to say, "Yes daddy." right?

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Just do slot :)

yeah....

You mean to say, "Yes daddy." right?

leave me alone duran... im too tired to argue

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Since he's looking to save room he may be interested in the aero port.. but you may only save bout .5 cuft or so..

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Since he's looking to save room he may be interested in the aero port.. but you may only save bout .5 cuft or so..

That's one of the awesers I was looking for! I was hopeing I could save more room but if that is the max I could save or close to it then I guess I'll just have to compromise and go for the slot port.

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Do external ports if you're worried about space inside the actual box

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Do external ports if you're worried about space inside the actual box

Well my problem is that I want room for my spair tire but I would have to make a really weird box and even with external ports I don't know if it will fit. I don't know how long they would be and if I could have like 2 but have then be short but still keep my tuning. I was already told the length of one but that seemed to long. I'll know for sure when I actualy start to get legitamit box designs.

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Do external ports if you're worried about space inside the actual box

Well my problem is that I want room for my spair tire but I would have to make a really weird box and even with external ports I don't know if it will fit. I don't know how long they would be and if I could have like 2 but have then be short but still keep my tuning. I was already told the length of one but that seemed to long. I'll know for sure when I actualy start to get legitamit box designs.

Keep in mind if you design a really weird shaped box, make sure its not too oddly shaped because the extra volume gained by the weird shape may not be "usable" volume. For example.. you have a cube with side lengths of 12 inches.. this yields one cubic foot of volume.. lets say you need 2 cubes total. You decide to add a rectangular box coming off of the side of the enclosure.. 4x4x108... (this is very exaggerated) so this will give you the 2 cubes needed but not much air, if any, is going to be flowing in the weird part of the box.. so in the end the speaker will only be able to use about 1 cube of the 2 cubes..

But anyway, what are your max external dimensions and where do you want the sub and port firing?

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Keep in mind if you design a really weird shaped box, make sure its not too oddly shaped because the extra volume gained by the weird shape may not be "usable" volume. For example.. you have a cube with side lengths of 12 inches.. this yields one cubic foot of volume.. lets say you need 2 cubes total. You decide to add a rectangular box coming off of the side of the enclosure.. 4x4x108... (this is very exaggerated) so this will give you the 2 cubes needed but not much air, if any, is going to be flowing in the weird part of the box.. so in the end the speaker will only be able to use about 1 cube of the 2 cubes..

But anyway, what are your max external dimensions and where do you want the sub and port firing?

im planning on having the sub and port facing the hatch of the trunk, i think like 8 is the max width in the center because of my spare tire. the max length is 35 and hight is 16. i would upload a sketch of what i want but photobucket wont let me upload anything.

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Keep in mind if you design a really weird shaped box, make sure its not too oddly shaped because the extra volume gained by the weird shape may not be "usable" volume. For example.. you have a cube with side lengths of 12 inches.. this yields one cubic foot of volume.. lets say you need 2 cubes total. You decide to add a rectangular box coming off of the side of the enclosure.. 4x4x108... (this is very exaggerated) so this will give you the 2 cubes needed but not much air, if any, is going to be flowing in the weird part of the box.. so in the end the speaker will only be able to use about 1 cube of the 2 cubes..

But anyway, what are your max external dimensions and where do you want the sub and port firing?

im planning on having the sub and port facing the hatch of the trunk, i think like 8 is the max width in the center because of my spare tire. the max length is 35 and hight is 16. i would upload a sketch of what i want but photobucket wont let me upload anything.

thats only 1.83 cuft.. you could get a 10 instead of a 12 or build the box big enough to go over the spare, but move the spare to another location in the trunk... maybe you could build the box so that it partially sits over the spare tire so you are able to move it whenever you need your spare

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thats only 1.83 cuft.. you could get a 10 instead of a 12 or build the box big enough to go over the spare, but move the spare to another location in the trunk... maybe you could build the box so that it partially sits over the spare tire so you are able to move it whenever you need your spare

well I was planning on having a compartment for the sub then have another with the port seperated by a thin compartment all are connected of course. Or use aero ports so I don't need the port compartment. And 8 inch. Is a rough guesstament

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thats only 1.83 cuft.. you could get a 10 instead of a 12 or build the box big enough to go over the spare, but move the spare to another location in the trunk... maybe you could build the box so that it partially sits over the spare tire so you are able to move it whenever you need your spare

well I was planning on having a compartment for the sub then have another with the port seperated by a thin compartment all are connected of course. Or use aero ports so I don't need the port compartment. And 8 inch. Is a rough guesstament

could you elaborate?

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thats only 1.83 cuft.. you could get a 10 instead of a 12 or build the box big enough to go over the spare, but move the spare to another location in the trunk... maybe you could build the box so that it partially sits over the spare tire so you are able to move it whenever you need your spare

well I was planning on having a compartment for the sub then have another with the port seperated by a thin compartment all are connected of course. Or use aero ports so I don't need the port compartment. And 8 inch. Is a rough guesstament

could you elaborate?

This is VERY VERY late but here are the pictures of what im thinking about doing, ive decided to go with aero ports, unless you can think of something else. the sub would be a 10" FI BL and the ports can be any diameter, the tuning is 33 Hz

IMG_02541.jpgIMG_02551.jpg

Edited by WhatsCS

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thats only 1.83 cuft.. you could get a 10 instead of a 12 or build the box big enough to go over the spare, but move the spare to another location in the trunk... maybe you could build the box so that it partially sits over the spare tire so you are able to move it whenever you need your spare

well I was planning on having a compartment for the sub then have another with the port seperated by a thin compartment all are connected of course. Or use aero ports so I don't need the port compartment. And 8 inch. Is a rough guesstament

could you elaborate?

This is VERY VERY late but here are the pictures of what im thinking about doing, ive decided to go with aero ports, unless you can think of something else. the sub would be a 10" FI BL and the ports can be any diameter, the tuning is 33 Hz

IMG_02541.jpgIMG_02551.jpg

So you want 1.2 cuft? and 15 sqft of port per cube? (this is straight from Fi's enclosure recommendation thread)

Well you have 1.213 cuft (assuming that you gave me outer dimensions and 0.75'' wood) just with the 15x15x13 part. The sub displaces .16 cuft. So 1.213-.16=1.053 which is a little short of 1.2 cuft.. can you extend make it like 15.5 instead of 13??? that would work out nicley.

I wouldn't use areo ports here.. The air around them will not really get used.. So I say use the part of the box that I was talkin about above for the box and then the other piece can be and external slot port. So can you extend that piece from 13 to 15.5? Also, is the curved piece going to be cosmetic or will it contribute to the volume of the enclosure?

Edited by Im Hung N ur Not

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So you want 1.2 cuft? and 15 sqft of port per cube? (this is straight from Fi's enclosure recommendation thread)

Well you have 1.213 cuft (assuming that you gave me outer dimensions and 0.75'' wood) just with the 15x15x13 part. The sub displaces .16 cuft. So 1.213-.16=1.053 which is a little short of 1.2 cuft.. can you extend make it like 15.5 instead of 13??? that would work out nicley.

I wouldn't use areo ports here.. The air around them will not really get used.. So I say use the part of the box that I was talkin about above for the box and then the other piece can be and external slot port. So can you extend that piece from 13 to 15.5? Also, is the curved piece going to be cosmetic or will it contribute to the volume of the enclosure?

yup, i want 1.2 cuft. ok, um i dont think i can extend the width because im trying to keep my spare tire, and i thought i wouldnt have enough room for a slot port, thats why i choose aero, but if you think i have room im down. the curved piece would be cosmetic, but if it could help with volume then i can use it. im planing on having some one build this for me, but i want a set design.

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yup, i want 1.2 cuft. ok, um i dont think i can extend the width because im trying to keep my spare tire, and i thought i wouldnt have enough room for a slot port, thats why i choose aero, but if you think i have room im down. the curved piece would be cosmetic, but if it could help with volume then i can use it. im planing on having some one build this for me, but i want a set design.

Well If you want 1.2 cuft net, you are going to need 1.36 cuft internal volume using an external port. The way the aero's are in the drawing is more trouble than its worth. I think an external port is the way to go for you..

What is the radius of that curve? We'll use it to get your last .15 cuft of box volume you need.

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yup, i want 1.2 cuft. ok, um i dont think i can extend the width because im trying to keep my spare tire, and i thought i wouldnt have enough room for a slot port, thats why i choose aero, but if you think i have room im down. the curved piece would be cosmetic, but if it could help with volume then i can use it. im planing on having some one build this for me, but i want a set design.

Well If you want 1.2 cuft net, you are going to need 1.36 cuft internal volume using an external port. The way the aero's are in the drawing is more trouble than its worth. I think an external port is the way to go for you..

What is the radius of that curve? We'll use it to get your last .15 cuft of box volume you need.

the radius would be 6" i think that might get me the amount i need, it can also be smaller. thats the maximum.

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the radius would be 6" i think that might get me the amount i need, it can also be smaller. thats the maximum.

There is one more piece of information I need. What is the max depth of the of the left side in the top view. (the part where the ports are firing in your drawing)

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the radius would be 6" i think that might get me the amount i need, it can also be smaller. thats the maximum.

There is one more piece of information I need. What is the max depth of the of the left side in the top view. (the part where the ports are firing in your drawing)

just found out the maximum depth of the box can be 11". So I'm going to scrap my idea And just build a normal box. Is 11" too shallow for a 10" FI BL

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