Fi Q 18 box design for trunk

[hondakilla98 29]

I want to run a Fi Q 18" off an saz-1500d in my new project, a 95 eldorado. I want to put it in the trunk. My trunk isn't tall enough to fire an 18 back so it'll have to fire up. I'm getting rid of the rear 6x9's, so I was thinking sub in the middle of the box firing up and a round port on either side firing into the empty speaker holes in the back deck. Box dimensions would be 38wide, 16.75tall with double baffle and 24 deep. Winisd is saying to tune 6.5 cu ft to 28hz i need two 4" round ports 10.15" long. That's .073 cu ft each. Or .015 total, and .24 for the sub. So .39 off 6.9 cu ft, giving me a net of 6.5 cu ft. Should the ports be flush with the top of the box, or stick up closer to the speaker holes in the back deck? and should I cut the carpet in the back deck for more airflow? Once the box is in the trunk there will be about 3-4 inches between the top of the box and rear deck of the car. I'm thinking I can put a notch in the back corner of the box(by the back of the car) for my hc1400 second battery. Then make an amp panel to mount against the back of the box to mount my amps on and hide the battery, and wires. So I'd need to subtract another .3 cu ft from the box for the battery notch. Giving me a new net of 6.2 cu ft.

Edited May 6, 2010 by hondakilla98

[scottxgtr 9]

youre going to choke that 18 with only 2 4" ports. you want a minimum of 10 sq in of port per cubic foot of box. and thats a minimum, 12-15 cubic inches is better.

[SpeakerBoy 64]

youre going to choke that 18 with only 2 4" ports. you want a minimum of 10 sq in of port per cubic foot of box. and thats a minimum, 12-15 cubic inches is better.

x2

[hondakilla98 29]

I plan on running aero ports. I'm just going off what winisd said for port. I was under the impression that when you run aero's that the rule of 12-16 went out the window. So two 6" aero's? If your going to tell me what I'm planning is wrong then you should also tell me how to correct it.

[scottxgtr 9]

I plan on running aero ports. I'm just going off what winisd said for port. I was under the impression that when you run aero's that the rule of 12-16 went out the window. So two 6" aero's? If your going to tell me what I'm planning is wrong then you should also tell me how to correct it.

you said round ports, and not aeros. if you want us to correct you, we need to know what you are using.

but yes, 2 6" aeros will be fine

[hondakilla98 29]

I just went to precision sound products and used their port calculator. It says with 2-6" aeros I'll need 27.5" ports. My max port length in that box is gonna be about 14". Can you put elbows on a round port to make it longer? And would I notice port noise in the car if i went with non aero's since the box is in the trunk?

[Duran 387]

If you have sufficient port area, slot or round it doesn't matter. Port noise doesn't discriminate.

The 12-16^2" of port area is only a rule of thumb, it's better to be exact. http://www.carstereo.com/help/Articles.cfm?id=31

[hondakilla98 29]

I used the calculator. And it says 120 sq in. With ports that big they have to be way too long to be feasible. So it looks like sealed is the way to go. The only way ports make sense is in a high tuned spl box. Then I could have enough port area and a port short enough to fit in the box. I used winisd to chart the sub and it doesn't look good. Did I do something wrong or read the graph incorrectly? The one that's nice and flat is the ported curve.

[superfishbone 1]

why dont you try building a trunk wall.. construct the box inside the trunk.. for an 18" you need atleast 7cubicft.. if your not going to put some stuff in your trunk might aswell maximize the space, face the sub inside the car.. tuned at 40hz..

sub facing up, port facing inside your car..

for the fi.. try to strap two saz1500d it would produce a clean 2600W.

the fi 18 can handle it.. dont worry.. hehehe

[superfishbone 1]

a port facing your trunk plus the sub facing up would produce huge amount of cancelation of power.. not to mention rattles would just absorb the power and outside you would just hear atleast 60% of the output..

[hondakilla98 29]

why dont you try building a trunk wall.. construct the box inside the trunk.. for an 18" you need atleast 7cubicft.. if your not going to put some stuff in your trunk might aswell maximize the space, face the sub inside the car.. tuned at 40hz..

sub facing up, port facing inside your car..

for the fi.. try to strap two saz1500d it would produce a clean 2600W.

the fi 18 can handle it.. dont worry.. hehehe

I don't want to lose my whole trunk. That's why I'm looking at 6 cu ft. Which according to Fi is fine for sealed. And I'm going to be running a Fi Q 18" probabaly with bp option. So an Rms rating of about 1200 watts. I think 2600 would be a bit much, don't you? I'm not looking at a BTL here. I want a clean sounding system with good output, not spl.

[stocks 2]

why dont you try building a trunk wall.. construct the box inside the trunk.. for an 18" you need atleast 7cubicft.. if your not going to put some stuff in your trunk might aswell maximize the space, face the sub inside the car.. tuned at 40hz..sub facing up, port facing inside your car.. for the fi.. try to strap two saz1500d it would produce a clean 2600W.the fi 18 can handle it.. dont worry.. hehehe

i hope you're kidding

you aren't kidding. being stupid is a bannable offense

Edited May 11, 2010 by cranberryyumyum

[hondakilla98 29]

why dont you try building a trunk wall.. construct the box inside the trunk.. for an 18" you need atleast 7cubicft.. if your not going to put some stuff in your trunk might aswell maximize the space, face the sub inside the car.. tuned at 40hz..sub facing up, port facing inside your car.. for the fi.. try to strap two saz1500d it would produce a clean 2600W.the fi 18 can handle it.. dont worry.. hehehe

i hope you're kidding

you aren't kidding. being stupid is a bannable offense

[stevemead08 752]

The Q dosent need more than rms to sound great. an saz1500 is a perfect match for the Q.

More than 1200 is just being stupid.

[superfishbone 1]

hey man im sorry i didn't mean to sound stupid to you guys. we just use the term "trunk wall" here in the Philippines because we sealed every possible air to go to the back, but the sub used was an 2 AA 18" mayhem, but it was on a sealed box, consumed about 3cubicft ea. strapped two saz 1500D to power 1 mayhem, in total used 4 saz1500D and was placed in the trunk..

and since your going to use 1 18" then you could do a ported one.

[bassahaulic 155]

7 cubes each :-O

[abigor 0]

hey man im sorry i didn't mean to sound stupid to you guys. we just use the term "trunk wall" here in the Philippines because we sealed every possible air to go to the back, but the sub used was an 2 AA 18" mayhem, but it was on a sealed box, consumed about 3cubicft ea. strapped two saz 1500D to power 1 mayhem, in total used 4 saz1500D and was placed in the trunk..

for the fi.. try to strap two saz1500d it would produce a clean 2600W.

the fi 18 can handle it.. dont worry.. hehehe

AA Mayhem is 2500 RMS while FI Q is 1000 RMS! so .... mayhem can handle 3000 watts of power .... ...... and the thread starter will only use FI Q not BTL

Edited May 11, 2010 by abigor

[superfishbone 1]

yeah i read the msg of the thread starter again, just notices it was an fi Q. my bad.. i just got used to the fi here in the philippines which is the SSD,BL and BTL.. if so the Q is just 1000rms? then saz1500 alone would do just fine ..

[///M5 2,833]

hey man im sorry i didn't mean to sound stupid to you guys. we just use the term "trunk wall" here in the Philippines because we sealed every possible air to go to the back, but the sub used was an 2 AA 18" mayhem, but it was on a sealed box, consumed about 3cubicft ea. strapped two saz 1500D to power 1 mayhem, in total used 4 saz1500D and was placed in the trunk..

and since your going to use 1 18" then you could do a ported one.

NO, because porting a leaky enclosure is not a good idea. You do NOT have a wall, you have an IB installation.

To the OP, if you can't fit a 18 ported buy a 15. So far from your posts I am not sure that the Q is right for you in the first place, buy you haven't shared goals so we all get to guess when we answer.

[superfishbone 1]

hey man im sorry i didn't mean to sound stupid to you guys. we just use the term "trunk wall" here in the Philippines because we sealed every possible air to go to the back, but the sub used was an 2 AA 18" mayhem, but it was on a sealed box, consumed about 3cubicft ea. strapped two saz 1500D to power 1 mayhem, in total used 4 saz1500D and was placed in the trunk..

and since your going to use 1 18" then you could do a ported one.

NO, because porting a leaky enclosure is not a good idea. You do NOT have a wall, you have an IB installation.

To the OP, if you can't fit a 18 ported buy a 15. So far from your posts I am not sure that the Q is right for you in the first place, buy you haven't shared goals so we all get to guess when we answer.

what does IB means? but thankyou for correcting me.. and for the info...

i agree maybe 18" for your trunk is too much.. one 15" or two 12" is a good option for sedans..

[stevemead08 752]

what does IB means? but thankyou for correcting me.. and for the info...

Infinite baffle

[hondakilla98 29]

To the OP, if you can't fit a 18 ported buy a 15. So far from your posts I am not sure that the Q is right for you in the first place, buy you haven't shared goals so we all get to guess when we answer.

Well let me start with goals. I want a clean system with good output. Over the last few months with my previous system, 98% of the time I had the sub turned way down. Just on enough to fill in the lows and sound good. Not overpowering like I had it before. That's when I decided that a Fi Q would be enough output wise for me. Since I wasn't turning up the RE SX15. Also the RE is wired at 2 ohm so it's only getting about 800 watts. I think the Q @ 1 ohm with about 1200 watts shouldn't have any trouble competing with the sx output wise.

This thread has helped me realize that a 15 is the way to go for me. That and alot of time talking with a few friends. I plan on buying a Q, and if that isn't enough I can always sell it and buy an Xcon. They both have basically the same box specs. So I shouldn't need to build a new box either.