build your port according to the size of the enslosure, if you want it 5 ft^3 (12 - 16 in^2/per cube of space). So your box is gonna need to be 5ft^3 after port area is taking into account, sub area and bracing are taking into account.

That doesnt mean design the box to be 5ft^3 and then start making the port because that will decrease the volume from 5ft^3.

Thanks. Doing the calculations now. Let you guys know later.

No problem and keep us posted, if you need any help with box desings give someone your max dimensions of area where you want enclosure to go and someone will assist you.

height x width x depth

i have a Fi BL 15 in a box thats exactly 4 cubes after port, mdf, and driver displacement. i love the way it sounds, even through a trunk. RE's calc said it was tuned to 34 hz i believe, but i dont think it actually gets tht low. more like 37ish. ill get you the exact specs of the box when i get home. i believe mine was somewhere around 16.5 H, 31 W, 21 D, with the port being 4 inches wide and goes straight back about 17 inches. but again, ill get the exact specs later tonight when i get home.

EDIT: by the way mine is the fully loaded, old version of the BL. although i dont think that matters...

Edited November 11, 200915 yr by Gioia69

So, since I need close to 6 cubes total, I decided I'd use the whole width of my trunk: 34". I was right on that one, because final external dimensions turned out to be:

Height: 20"

Width: 34"

Length: 20" (external)

Height: 17.75"

Width: 32.5"

Length 18.5" (internal)

Port opening:

Height: 17.75"

Width: 3.4"

Total area of opening: 60.35" sq

Port length: 34"

Port volume: 2.123 cuft

Tuning: 31-32Hz

Final box volume after sub and port displacement: 4.053cuft

Hope she fits, cause that's about it for space... Wow... Thought I had a lot more room for junk in the trunk.

PS: Is there an equation for tuning slot ports? I have the equation for circular ports memorized, so I just found out everything for a circular port with the same area.

It's the same. All that matters when designing different shaped ports is the port is port area. 50 sq. inches in slot port is the same as 50 sq. inches in a round port.

It's the same. All that matters when designing different shaped ports is the port is port area. 50 sq. inches in slot port is the same as 50 sq. inches in a round port.

Understood. I was just wondering if there was another equation, as this one uses the radius: ((8466.4xR^2)/(VbxFb^2))-(1.463xR)

R=radius

Vb=box volume, (cuft)

Fb=tuning frequency

Edited November 12, 200915 yr by Don Ganso

ah. Well there are a few port calculators on the web that just use the area and not designed specifically with round ports in mind. I think maybe JL's website has one.

Thanks, will do. I'm curious, should I get a binding post terminal or just run the wires through the box, (which is what I'm doing on my current box).

Thanks, will do. I'm curious, should I get a binding post terminal or just run the wires through the box, (which is what I'm doing on my current box).

Run the wires through the box. Its cheaper too. I always thought, the less connections, the better the power flow. I could be wrong as I have heard many people with the opposite opinion. I'll stick with it.

Edited November 13, 200915 yr by bigrank916

Thanks, will do. I'm curious, should I get a binding post terminal or just run the wires through the box, (which is what I'm doing on my current box).

Run the wires through the box. Its cheaper too. I always thought, the less connections, the better the power flow. I could be wrong as I have heard many people with the opposite opinion. I'll stick with it.

X2

The connections can be fine, but a terminal cup never makes sense. Drill through terminals are okay. Of course there is no negative to just run it out the port.

The connections can be fine, but a terminal cup never makes sense. Drill through terminals are okay. Of course there is no negative to just run it out the port.

probably won't have enough to run it out the port unless I get some more... Hoping I could just use what I have left... But I'd rather run it through the port than punch holes in my beautiful box lol.

Or just get you some bolts and attach the wire to one side inside the box and have wires coming off of it on the outside going to the amp (check out some build logs on here cause some boxes are like what im talking about).

Or just get you some bolts and attach the wire to one side inside the box and have wires coming off of it on the outside going to the amp (check out some build logs on here cause some boxes are like what im talking about).

Yeah I think I know what you're talking about... Saw it somewhere on here...

Yeah thats what I plan on doing for my next box.

Alright, I think I know what I'm going to do... I'll keep everybody posted. Thanks.