Box/Port help for Zv3 18

[bgowdy31]

I would put an internal aero so it takes up some of the room . I think that is to big

yea im doing a internal aeroport, thats why the box is going to be that size. the box will be 5.58 gross, the ZV3 18 takes up .16cu for displacement, im doing alittle bit of a rounding to corners, and some alittle bracing on the inside so the size is going to come down. but do i multiply by 5.58?

[bgowdy31]

how do you know your box is going to be 5.58 if you don't know what your port displacement is yet?

5.58 before all the displacement

[bgowdy31]

he wants to do an external aero

nah im doing an internal aero

[321slapinbass]

remember you have to subtract all displacements (5.58 minus everything added into the box). now I just did the math for you so..... port = 11.75" long with a displacement of .36 cubes. sub = displacement of .16 cubes. your net volume is now 5.06 cubes tuned to 39.0 hz with 9.9 inches of port per cube.

[bgowdy31]

remember you have to subtract all displacements. now I just did the math for you so..... port = 11.75" long with a displacement of .376 cubes. sub = displacement of .16 cubes. your net volume is now 5.04 cubes tuned to 39.07 hz with 9.96 inches of port per cube.

ok so do i need to go with more port?

so wait do you calculate the amount of port by the total cubes or cubes after displacement? i was told to calculate if by the gross cubes before displacement, but that may have been wrong?

[321slapinbass]

yes 9.9 in per cube is good for aeros.

and for the the port area question you want to calculate it with the net volume. it doesn't make sense to calculate it with the gross volume because you box is no longer that big.... do you understand? you can't use a number that no longer exists or means anything to the box. 5.06 is the actual amount of air in the box.

50.24 / 5.06 = 9.92

[bgowdy31]

yes 9.9 in per cube is good for aeros.

and for the the port area question you want to calculate it with the net volume. it doesn't make sense to calculate it with the gross volume because you box is no longer that big.... do you understand? you can't use a number that no longer exists or means anything to the box. 5.06 is the actual amount of air in the box.

50.24 / 5.06 = 9.92

ok i see what your saying. so in your opinion should i be below 5.06 net for this sub, i know the sundown site calls for 4 cubes net i was worried about 4 cubes being to peaky but i think the peakiness has to do with the port. i mean if i can do like 4.5 cubes net with 1 8" aero port and it not be to peaky then id go smaller for saving room.

[321slapinbass]

I really don't know much about zv3's (or a lot of subs for that matter), I just know my boxes haha. but sure if you want smaller then post up some dimensions of the current box and tell me how you want to shrink it (height ,depth...etc) and I can work with them.

[bgowdy31]

I really don't know much about zv3's (or a lot of subs for that matter), I just know my boxes haha. but sure if you want smaller then post up some dimensions of the current box and tell me how you want to shrink it (height ,depth...etc) and I can work with them.

i mean i already have it shrunk down and planned on paper. i dont really want it to be smaller, just want whats best lol. also the inside back corners of the box are rounded but dont take very much space at all. so with that you calculated it would probly be closer to 5.0 cubes, as well i have 2 althreads front to back. its kind of hard to explain because im at work.

[321slapinbass]

ok cool, and yeah those things wont take up much space. it might rise the tuning ~ 0.5hz but you won't even notice that small of an increase.