18" Enclosure for a trunk car...need direction

[adjetta 10+ year member]

So I'm sure we have all experienced this question on her before, so I apologize in advance lol

So I have an 18" Sundown Z V.4 on an aq2200, and I am putting it in the trunk of my 02 infiniti I35(same as maxima). My biggest concern is that I really do not want to top fire due to a profound hatred of rattle/dirty bass. I have 19.5 inches of headroom in the trunk, so this is my issue. I am trying to find a way to front fire, but its proving difficult...I was thinking about building the box in two sections ( 37 x 19.5 x 14 ) and on the interior of the open side of each box I would have an inner mdf rim so I could glue/bolt the two halfs together...alot of work right? only benefit is that it gets me 9 cubes after disp View attachment 26546105

is there any problem with the woofer basically being 1/4th of an inch from the ground? or would bolting two boxes together cause any issues?

I also debated trying to angle the front but I'm nearly positive its going to hit the bottom every angle ive tried has thus far.

Do I really have to settle for a 15?

Click to read more...

 

[T3mpest 10+ year member]

Is that 37 x 19.5 x 14 your available space? That's only 6 cubes external which is NOT enough for a 18 to begin with, unless you going sealed which a ported 15 can be just as loud or moreso, especially since you won't be cramming it in.

 

[adjetta 10+ year member]

no, i'm building two of the boxes with the 37 x 19.5 x 14, and joining them in thr trunk, but i'm just seeking an alternative

 

[DonH 5,000+ posts]

Is that 37 x 19.5 x 14 your available space? That's only 6 cubes external which is NOT enough for a 18 to begin with, unless you going sealed which a ported 15 can be just as loud or moreso, especially since you won't be cramming it in.

your logic as to why a 15" ported would be louder? a ported box is magically louder I presume...

OP have you thought about building the box INSIDE the trunk??? It can be done and has been done many times before. its messy and tricky but can be done when using the right tools for proper assembly.

 

[T3mpest 10+ year member]

your logic as to why a 15" ported would be louder? a ported box is magically louder I presume...
OP have you thought about building the box INSIDE the trunk??? It can be done and has been done many times before. its messy and tricky but can be done when using the right tools for proper assembly.

A ported 15 is generally going to be about as loud as a sealed 18. It's going to be a bandwidth dependent thing, but the extra displacement the 18 has is equalled generally speaking by the ability of the port and woofer at frequencies near tuning. Up top woofer sensativity plays a role and that can go either way, generally 18's win again due to cone area, but not alwasy. Generally people like peaky, if he's trying to cram an 18 in his vehicle I assume that's because he wants both loud and low, a ported 15 can provide that kind of peaky bottom end response easier than a sealed box generally will.

 

[adjetta 10+ year member]

your logic as to why a 15" ported would be louder? a ported box is magically louder I presume...
OP have you thought about building the box INSIDE the trunk??? It can be done and has been done many times before. its messy and tricky but can be done when using the right tools for proper assembly.

oh I must have made a mess of my first post, i am attempting to build a box that will net me around 9 cubes after disp, and i'm porting, firing, and sealing it into the cabin

I lack tools and experience, so i'm trying to exhaust my enclosure design options, before I opt for this method, I might attempt it on my own, but honestly I could see myself wasting a bucnh of dough on materials just to make a hash of it

A ported 15 is generally going to be about as loud as a sealed 18. It's going to be a bandwidth dependent thing, but the extra displacement the 18 has is equalled generally speaking by the ability of the port and woofer at frequencies near tuning. Up top woofer sensativity plays a role and that can go either way, generally 18's win again due to cone area, but not alwasy. Generally people like peaky, if he's trying to cram an 18 in his vehicle I assume that's because he wants both loud and low, a ported 15 can provide that kind of peaky bottom end response easier than a sealed box generally will.

yea im considering a 15, but I am really inclined to do the 18 because its the best bang for my buck and they move a little more air

 

[mlstrass 5,000+ posts]

Don't think that sub really needs 9^3 net...

 

[NASTY08IMPALA 5,000+ posts]

Don't think that sub really needs 9^3 net...

Exactly maybe 9^3 gross ..should only need 6-6.5...and op this guy im quoting runs a single 18 is his maxima on about 7k rms..might pick his brain on sub/port orientation

 

[DonH 5,000+ posts]

A ported 15 is generally going to be about as loud as a sealed 18. It's going to be a bandwidth dependent thing, but the extra displacement the 18 has is equalled generally speaking by the ability of the port and woofer at frequencies near tuning. Up top woofer sensativity plays a role and that can go either way, generally 18's win again due to cone area, but not alwasy. Generally people like peaky, if he's trying to cram an 18 in his vehicle I assume that's because he wants both loud and low, a ported 15 can provide that kind of peaky bottom end response easier than a sealed box generally will.

im sorry but when did this forum turn to ****? who the heck wants a peaky box? jesus this is MUSIC!!! since when does someone enjoy a one not eownder when listening to music? that is all you described.... And your argument is invalid to plainly state a 15" ported is louder than a 18" sealed... you said it yourself, the 18 has more cone area... in the end, cone area always wins

 

[T3mpest 10+ year member]

im sorry but when did this forum turn to ****? who the heck wants a peaky box? jesus this is MUSIC!!! since when does someone enjoy a one not eownder when listening to music? that is all you described.... And your argument is invalid to plainly state a 15" ported is louder than a 18" sealed... you said it yourself, the 18 has more cone area... in the end, cone area always wins

Your assuming an awful lot aren't there Don? I said peaky, not one not wonder. If you think most of this forum doesn't like extra bass in the 30-40hz region your fooling yourself. Go look at almost every internet brands recommended box size, it's a moderately large to large ported box tuned at 30something hz. Most people much prefer the sound of a box ported tuned in the mid 30's, which believe it or not is generally not a flat response, especially after cabin gain. Cone area always win, lol. So overall displacement including xmax and BL and powerhandling have no say here... Good to know, I better remember the 12inch wal-mart lightning audio is going to crush a DC level 5 10. That's a black and white statement, "cone are always wins". Upper bass comes down to woofer sensativity, as well as cone area, if you have a slightly stronger motor on the 15 it can be louder up top. Down low is about displacement and a 15 ported def has the advantage as you get near tuning, if you tune low enough, that will cover most music you'd play anyways.

I never even "plainly" stated anything. I said a ported 15 can be AS LOUD OR LOUDER than a sealed 18. That leaves quite a bit of room for all the real world factors. It's going to be subwoofer and car dependent, but the overall displacement ability of a ported 15 and a sealed 18 are generally pretty close. Most people are concerend mostly about 40 and down and you can def be louder there with less cone area and a more effecient box design. He wants an 18 for the most bass for his money. I think when all factors are considered including ease of the build, which a 15 ported could drop right in, it's going to give him just about as much bass for his money and be a much easier build.

See those 2 really close lines? Those are a sealed 18 and ported 15, of the same model, SI HT18 and 15 respectively. As you can see, when shooting for a response to match the sealed 18, it can be easily reached and is only lacking output below 20hz. That's a wide very large bandwidth too. If like most car audio guys, he isn't as worried about what happens between 20-25hz, you could easily gain a few extra Db's in the mid 30hz range over that sealed alignment, which on most music is going to sound louder to the ear, most peoples bass heavy music doesn't drop below 30hz all that much. You done looking foolish attacking me for no reason yet? There are plenty of noobs on this site you can go try and correct, I'm not one of them. I haven't said anything wrong or even controversial, but if you think most people in this hobby prefer the frequency response of a sealed box your in for a rude awakening.