15" Fi Bl enclosure design

[Poundhardheh 0]

Hey, I just bought 1 15" Fi Bl with the cooling option and it's a 1 ohm DVC because the amp I'm running is a JL 1000/1 and can put 1000 watts for 1-4 ohms.

My dillema is my box design, It will be a dual L-port box.

Heres the numbers I have so far...

Max Dimensions - 45w x 17h x 24d

Heres my numbers right now...

44w x 17h x 20d

3/4 MDF

2 ports...3 inch wide by 8 inch which is 93 square port area.

4.9 Cube box

32.8hz

Square Port Volume Displaced - 3648

Any numbers I should change?

Would it be better 1 port 6 wide by 16 inches?

Also would that be a good size and frequency?? CHEERS

[ackslaxrichard 0]

I think 1 port would be better...the dimensions of my box are below and the box is great

[Poundhardheh 0]

Why would it be better for the box just to have 1 port?

Do my numbers look good?

[Duran 387]

Two ports is complicated, and you probably don't know how to calculate it. Stick with one.

[ackslaxrichard 0]

You should do 3-4 cubes...definitely not 5

The height imo should just be flush with the height of the seats for looks and the length and width will have to be adjusted if you do 3-4 instead of 4.9

the port sounds fine

[Poundhardheh 0]

Width - 41

Height - 17

Depth - 18

3/4 MDF

Port Width - 5

Port Length 1 - 12.25

Length 2 - 16

Port Area - 77.5

Volume Displaced - 2849

Box Volume - 4.1 cubes

Frequency - 33.7

Any numbers to change? Single L-Port now

[ackslaxrichard 0]

i still think you should lower ur box volume to less than 4 cubes and also tune it to like 32 hz

also at that box volume your port are should be about 57.4..about 14 in^2 per ft^3

Edited March 9, 2009 by Richie25

[Poundhardheh 0]

What's the problem with having a little to many Cubes?

And what's the problem with too much port area?

Alway's heard bigger the better to an extent!

[-M- 0]

The problem with too many cubes is you run a higher chance of bottoming out your sub on rated power.

[Poundhardheh 0]

So maybe drop it down around 3.7-3.9 cubes?

And around 33 - 34hz?

[Poundhardheh 0]

The reason I'm thinking around 33 or so, is because I hear if you tune it lower it will lose SPL.

That true?

Also would 4.1 cubes or so be good before displacement? Tuned at 33hz

After some bracing and the sub displacement, give me an estimate of how much the cubes will lower?

And will the frequency change at all?

[Poundhardheh 0]

bump

[ackslaxrichard 0]

ok well do you want just an all around loud sub...or are u looking for it to hit the lows harder

I know q's kill lows but idk about bl's

I wouldn't worry about losing SPL...its gonna be loud and sound good

[ackslaxrichard 0]

what does bump mean...i never saw it a t first but now its everywhere

[ackslaxrichard 0]

im pretty sure more cubes is gonna make ur sub not as loud

correct me if im wrong but bigger box = less power

my box works great...ive had some amp troubles...but the box is amazing and i think the bl would do great in a box a little bigger than mine(between 3.5-4 cubes) and for tuning it i htink 32-33 hz would also be fine

[Duran 387]

im pretty sure more cubes is gonna make ur sub not as loud

correct me if im wrong but bigger box = less power

No bigger boxes are louder, they raise efficiency, that means it takes less power to be just as loud.

[ackslaxrichard 0]

OK so what would you say for his dimensions?

[Poundhardheh 0]

So duran...this sound good?

Port is 7 x 20 which is port area of 101.5

Volume before displacement - 4.3 cubes

Volume Displaced - 4541

Frequency - 34.5hz

[Duran 387]

In that box the maximum port area I would go is 68 sq. in.

[Poundhardheh 0]

Ok, just wondering But why?

[Duran 387]

Any more than that and you risk unloading (on music).

[Poundhardheh 0]

What's unloading on music?

[Duran 387]

The reason guys who compete have such monstrous enclosures and ports is to raise efficiency. They tune really high and only play tones, not music. So they are seldom at rick of mechanical failure (unloading), you on the other hand will be playing music with changing frequencies, combine that with too much port area ad you get mechanical failure.

[-M- 0]

great way to put it!

[Poundhardheh 0]

So like 4.3 cubes with aroung 60 - 70 port area and tuned to around 33-35hz