INFORMATION: I own a 2002 pt cruiser. I am going to soon be buying a Fi Q18 and a AQ1200D for my car. I have calculated maximum external volume that the enclosure can be and it is around 8ft^3. I will upload some pictures tomorrow but its dark outside so I can't go take any pics.

Two Options:

1. Sealed. Would allow me to downsize the box a bit to around 6ft^3 and give the sub some more breathing room.

2. Ported. I would keep the volume at the max and port it to 28hz like recommended. My only concern is that the space between the Q18 and the rear hatch is 4 inches. I know this will affect the sound but I don't think it will be too big of a problem.

So what should I pick? Is ported all that louder? Will it matter with an 18 at around 1000-1300 watts? Does Sealed have that much more SQ?

-Sound Quality is very important to me. I want to be able to feel clear punches and not just buzzing unless thats the way the song is.

-I listen to rap/techno/dubstep/alternative, pretty much everything with bass.

-The sub cannot be pointed towards the front or up only back!

-I am currently using http://www.clubknowledge.com/Car_Audio_FAQ/?t16 to calculate port size/length. Is this an accurate formula/information?

-I am not changing my selection in Sub or Amp and I would appreciate it if only the questions listed are answered.

-Thats great if you have suggestions for how I do things but this post is really only for the above questions.

Thank you for helping me out!!!

I will make sure to post pics tomorrow.

PS: I am sort of unclear on what the different options do when purchasing a fi subwoofer. Which items should i select? or should I get all of them?

Edited January 27, 201114 yr by SINTORMAN

Welcome ....

Sealed box will have a more linear response. I would just do a ported enclosure and tune low, like the 28hz you stated.

On paper a ported enclosure is ~3dB louder then sealed, but box size, driver positioning and placement, and cabin characteristics will change this.

Most proper ported enclosures w/same drivers are louder then sealed.

I had a 18" bl for some time in a ported enclosure and loved it. Sounded very clear on drums, attacks in rock, and was loud on rap

Thank you for the warm welcome! I do want to go ported but I am concerned about two things. The sub side of the box will be 4 inches away from the plastic of the hatch. I know this is going to cause even more rattling but will it make the sound any different?

Two: Is the website I listed a good source for porting? I put in the fi recommended stats into the formula and I got almost the same results.

Why not get a 15"?

Why not get a 15"?

Well I believe the phrase go big or go home applies.

1. only a bit more money so why not.

2. looks

3. Why not?

Why not get a 15"?

Well I believe the phrase go big or go home applies.

1. only a bit more money so why not.

2. looks

3. Why not?

These are pictures of my car with cardboard templates of the sides of the box.

http://picasaweb.google.com/116170605906548217544/NewSubwoofer?feat=directlink

The "sub" box in there right now will definitely not be in there when I get the 18.

Edited January 27, 201114 yr by SINTORMAN

Why not get a 15"?

Well I believe the phrase go big or go home applies.

1. only a bit more money so why not.

2. looks

3. Why not?

Generally more cone area = more output, but putting a big driver in a small box will have negative effects compared to a step down in size driver in the proper enclosure.

Just because a sand rail is fast, doesn't mean it'll work best for rock crawling (bad analogy I know)

Why not get a 15"?

Well I believe the phrase go big or go home applies.

1. only a bit more money so why not.

2. looks

3. Why not?

Generally more cone area = more output, but putting a big driver in a small box will have negative effects compared to a step down in size driver in the proper enclosure.

Just because a sand rail is fast, doesn't mean it'll work best for rock crawling (bad analogy I know)

I think I will be fine considering the recommended ported volume is 6-10 ft^3 and I am close to the middle.

Why not get a 15"?

Well I believe the phrase go big or go home applies.

1. only a bit more money so why not.

2. looks

3. Why not?

Generally more cone area = more output, but putting a big driver in a small box will have negative effects compared to a step down in size driver in the proper enclosure.

Just because a sand rail is fast, doesn't mean it'll work best for rock crawling (bad analogy I know)

I think I will be fine considering the recommended ported volume is 6-10 ft^3 and I am close to the middle.

sounds like you have plenty of volume for a sealed enclosure then

If you do a sealed enclosure you may want to do the "High QTS" option (note: if you do the high qts then that Q should never be played in a ported enclosure).

I'd rather have a 15" sub ported in an optimal enclosure than an 18" sub in a sealed box.

The 15" sub will be easier to sell, and may be louder ported !

Don't forget you need room to put your amps and batt, and all !!! And room for everything to run cool. If it's too tight you can have heat problems. Electronics don't like too much heat.

A BL fits your needs better than the Q and conveniently can fit in a slightly smaller ported box.

So I guess I will do 18" sealed because I am fine and prefer a flat response with my music. So I will shrink the sub enclosure to like 6-6.5 ft^3. And I was planning on putting the amp on the back of the enclosure behind the back seat where there is plenty of room and best of all not visible from the outside. So high qts, what about the cooling, p chamfer, Spider, and I heat ring? Should I get all of those upgrades? Plus sealed will give the sub a little more breathing room to reduce massive vibrations on the back hatch.

Anything else I should know when making the enclosure?

PS: I was also planning on bolting the enclosure to the frame but have like 1 inch thick rubber spacers to reduce vibrating between direct contact of frame to enclosure. Is this a good idea?

PSS: Should I mount the sub directly in the middle of the surface or near the bottom where its the deepest?

Edited January 27, 201114 yr by SINTORMAN

I thought your name looked familar stefan. I have seen comments of yours at sundowns website.

I thought your name looked familar stefan. I have seen comments of yours at sundowns website.

yeah, anyone can comment

Since I caught you, can you offer any advice from my questions in post #15

Rubber mounts inbetween box and floor isn't a bad idea.

I'd get all the upgrades, gives you some increased power handling and cooling (doesn't cost that much either)

Do you have a design yet for the box? How close would the port be to the magnet if you mounted the driver in the center?

Rubber mounts inbetween box and floor isn't a bad idea.

I'd get all the upgrades, gives you some increased power handling and cooling (doesn't cost that much either)

Do you have a design yet for the box? How close would the port be to the magnet if you mounted the driver in the center?

I've been thinking I and guess I will go sealed just because it fits my situation better. The measurements are H:24.5" W:36" D1:18.5" D2:11.5".

So a wedge

Edited January 29, 201114 yr by SINTORMAN

Rubber mounts inbetween box and floor isn't a bad idea.

I'd get all the upgrades, gives you some increased power handling and cooling (doesn't cost that much either)

Do you have a design yet for the box? How close would the port be to the magnet if you mounted the driver in the center?

I've been thinking I and guess I will go sealed just because it fits my situation better. The measurements are H:24.5" W:36" D1:18.5" D2:11.5".

So a wedge

then it probably won't matter where it's mounted.

Rubber mounts inbetween box and floor isn't a bad idea.

I'd get all the upgrades, gives you some increased power handling and cooling (doesn't cost that much either)

Do you have a design yet for the box? How close would the port be to the magnet if you mounted the driver in the center?

I've been thinking I and guess I will go sealed just because it fits my situation better. The measurements are H:24.5" W:36" D1:18.5" D2:11.5".

So a wedge

then it probably won't matter where it's mounted.

k Kool thanks for all the help.