tuning 2 18s btls with round ports

[oscar r 0]

so i want to use 2 10" aero ports, sono tubes,... and i dont know how to find out how long they should be, i want to start off at 32hz, on a box that is 15.4cf or a box that is 16.6cf,

i want to put the ports in side so do i have to subtract the area space of the tubes or just find the calculation with out taking out the area space of the tubes???

[Kanaworm$ 292]

Find out the id of the sono tube and add the wall thickness to come up with the displacement. To find the tuning is the same as finding the length of a slot port.

For 15.4ft^3 tuned to 32hz each port should be 19.53"

For 16.6ft^3 tuned to 32hz each port should be 17.59"

http://www.carstereo...icles.cfm?id=31

[jlftn 11]

well youre gunna need to make them very long if you want 32hz out of 10" tubes, when you find youre airspace just find the interneal space of the box and subtract the volume of the tubes, but i wouldnt go with 10" IMO, multiple 4" and 6" will do fine, go to any online calculator and type in 10" round port and 32 hz and it will be crazy long.

For two 18's I'd go with a slot port to get the port area you need but if you really want the round ports then try the 6" ports

hope that helps!

[jlftn 11]

hmm, less than 20" isnt as long as i expected

[oscar r 0]

Find out the id of the sono tube and add the wall thickness to come up with the displacement. To find the tuning is the same as finding the length of a slot port.

For 15.4ft^3 tuned to 32hz each port should be 19.53"

For 16.6ft^3 tuned to 32hz each port should be 17.59"

http://www.carstereo...icles.cfm?id=31

10" PVC pipe

OD = 10.5"

ID = 9.9"

Wall Thickness = .3"

then the wood on the box is 3/4"

... so if i do my box at 15.4 cf i just stick in the 19.53" tube and its going to be at 32hz?

[oscar r 0]

well youre gunna need to make them very long if you want 32hz out of 10" tubes, when you find youre airspace just find the interneal space of the box and subtract the volume of the tubes, but i wouldnt go with 10" IMO, multiple 4" and 6" will do fine, go to any online calculator and type in 10" round port and 32 hz and it will be crazy long.

For two 18's I'd go with a slot port to get the port area you need but if you really want the round ports then try the 6" ports

hope that helps!

oh well this dude has 2 18s bls and his box is at 15.4cf and his tubes are 23.something and hes at 30hz,

i have my btls on a 11cf box at 34 but i want mines to move air like his...

[Kanaworm$ 292]

Find out the id of the sono tube and add the wall thickness to come up with the displacement. To find the tuning is the same as finding the length of a slot port.

For 15.4ft^3 tuned to 32hz each port should be 19.53"

For 16.6ft^3 tuned to 32hz each port should be 17.59"

http://www.carstereo...icles.cfm?id=31

10" PVC pipe

OD = 10.5"

ID = 9.9"

Wall Thickness = .3"

then the wood on the box is 3/4"

... so if i do my box at 15.4 cf i just stick in the 19.53" tube and its going to be at 32hz?

You will have to have account for wood, bracing, port and speaker displacement to come up with a net volume of either 15.4 or 16.6 cubic feet.

[jlftn 11]

well youre gunna need to make them very long if you want 32hz out of 10" tubes, when you find youre airspace just find the interneal space of the box and subtract the volume of the tubes, but i wouldnt go with 10" IMO, multiple 4" and 6" will do fine, go to any online calculator and type in 10" round port and 32 hz and it will be crazy long.

For two 18's I'd go with a slot port to get the port area you need but if you really want the round ports then try the 6" ports

hope that helps!

oh well this dude has 2 18s bls and his box is at 15.4cf and his tubes are 23.something and hes at 30hz,

i have my btls on a 11cf box at 34 but i want mines to move air like his...

that is really impressive, with 2 10" tubes youre port area is 157 sq. in, on my 2 18s i run slot ports and get about 159 sq in with 3" slot ports, either way should be good! that setup obviously moves air!

[oscar r 0]

Find out the id of the sono tube and add the wall thickness to come up with the displacement. To find the tuning is the same as finding the length of a slot port.

For 15.4ft^3 tuned to 32hz each port should be 19.53"

For 16.6ft^3 tuned to 32hz each port should be 17.59"

http://www.carstereo...icles.cfm?id=31

10" PVC pipe

OD = 10.5"

ID = 9.9"

Wall Thickness = .3"

then the wood on the box is 3/4"

... so if i do my box at 15.4 cf i just stick in the 19.53" tube and its going to be at 32hz?

You will have to have account for wood, bracing, port and speaker displacement to come up with a net volume of either 15.4 or 16.6 cubic feet.

ok

the subs are .26 each x2 = .52cf

ports .74 x2 = 1.48cf

bracing =1.0cf

total = 3cf

and my box is going to be one of these

48x29x24 wood is 3/4" = 16.6cf

other box

48x27x24 wood 3/4" = 15.4cf

i just want the box to b at least 15.4cf after displacement, i know how to calculate the tube length but i dont know if to

1) subtract the displacement (3cf) from the box (16.6cf) and do the math for tube length

2) or just to the math for tube length with out displacement

[oscar r 0]

well youre gunna need to make them very long if you want 32hz out of 10" tubes, when you find youre airspace just find the interneal space of the box and subtract the volume of the tubes, but i wouldnt go with 10" IMO, multiple 4" and 6" will do fine, go to any online calculator and type in 10" round port and 32 hz and it will be crazy long.

For two 18's I'd go with a slot port to get the port area you need but if you really want the round ports then try the 6" ports

hope that helps!

oh well this dude has 2 18s bls and his box is at 15.4cf and his tubes are 23.something and hes at 30hz,

i have my btls on a 11cf box at 34 but i want mines to move air like his...

that is really impressive, with 2 10" tubes youre port area is 157 sq. in, on my 2 18s i run slot ports and get about 159 sq in with 3" slot ports, either way should be good! that setup obviously moves air!

yea thats want my system to do

isint 12ci to 16ci recomended for each cubic foot?

and he has 15.4cf and 15.4cfx12cf is 184.8 and he has 157sq.in of port area

well he told me he has 15.4cf net, it that just the box with out displacement or with displacement?

[Kanaworm$ 292]

Net will be the total with all displacements accounted for. Calculate the displacment of the port as part of the enclosure as it is inside the box taking up space.

[oscar r 0]

Net will be the total with all displacements accounted for. Calculate the displacment of the port as part of the enclosure as it is inside the box taking up space.

ok thnx ill upload some pics and videos like in a week, bc i ordered the pvc pipe online

[sefugi 166]

Waitin' on the pics I wanna see that setup!

[Millertime1028 0]

15.4 cu/ft is after all displacements. I wanted each 18 to theoretically see 7.5- 8 cubes net each. Ports are exactly 22.1 inches long achieving a tuning of roughly 30 hz. Make sure when you buy the sono tubes that you measure the inside diameter as sometimes they are not the exact diameter that they are listed as. Can be off as much as .75 inches. I've ran BTLs for a short time in the box you see in my vid's with good results. Box placement played a big roll on this setup as far as #'s and peak freq went, so if you have some room to play with, do some testing and see what works best for your specific vehicle.

Edited July 15, 2010 by Millertime1028

[bassahaulic 155]

You do realize that is a 6000+ watt amp since he's running 16v right?........

How much power do you have? What do you drive?

And in the video with all the hair moving those aren't Fi BL's..... They are DC LV4 XL's.