KU40

nvm

either will work fine

port displacement is just port width + .75 (to allow for the wood) X height X depth. as for the rest of your post, I couldn't understand half of it. the problem with 18" on the outside is that now you will have to have two port 180's (or three boards to make it). but the problem with that is that your third board is only going to be something like 3-4" I think. Which barely covers the turnaround opening right there. I don't know for sure that it effects the sound in a negative way, but I just like to be safe and have each board go at least 1/3 of the way into the box, so that the waves know they are going down a path. hard to explain, maybe it makes no sense, and maybe I'm just wrong. but i'm just conservative like that.

i would figure displacement to be around .1 cubic foot. is your box 18" deep on the inside? if so, that only gives you 15" of depth for the first part of the port, because you have to leave 3" from the back wall for the waves to turn around (have to keep the distance to every wall 3", whether it be side or front and back). add in the .75 for the front baffle, and you have 15.75" on the first portion of the port. now onto the second portion, which is starting at the back wall. you will gain 3.75" from the turn (you measure down the center of the port, so if you'd draw a line down the center of the whole port, this 180 degree turn isn't just a flip around. there is a rectangled edge there, and you have to account for that.). that will give you 19.5" so far. your second piece of wood will have to be 14.5" long to get to the full 34". now if that is 18" deep on the outside......it will be a little more difficult. there is another problem if that's the case, which will probably force you to change your port.

you have to plug in the number after all displacement. so 2.5. however, you have to realize that the port will be different for the 2.5 box than for the 3.0. so you may not end up with 3.0 total. as for the port, you're gonna need more than just one 3" port. that only gives you 7 square inches of port area. I suggest you at least triple it.

you need to use wood glue to hold all joints together. the glue is really what holds the box together,and the screws just hold the joints together while the glue dries (though I use clamps too). they may help a little with structural integrity, but not a ton. after you get joints together, run over them from the inside with some sort of caulk or silicone, or something like that. that will insure it's airtight in terms of joints. there really is no difference in using a round port or slot port, or anything. I would say that a round port may be a little more difficult here, though, because it would have to be so long. you would probably have to use some angles and elbows. what I have done to seal off my ports is pretty basic. just cut a piece of wood that will cover the hole, and you just screw it over the hole. that's it. I had a couple air leaks around mine, though. But for this I wouldn't recommend a liquid (or gel like) sealant like you used on the joints on the inside. I would use something like rope caulk, so that you can take it off and reuse it again as you plug and unplug the port. screws I use are just 1.5" drywall screws, about 5 inches apart.

seems like we have a wild one here

if you listen to mainly rap, I'd tune to the higher figure, 32 hz. When you plug into port calculations, you have to subtract out the port and driver displacement. With Mustangs I have seen the most problems not with the size of box that'll sit in the trunk, but the size that will fit through the opening. You have to be careful there, as I think the trunk opening is a little small, so fitting a larger box in there may be a little more difficult. if you do 3.0 cubic feet before all displacement, you'll be pretty good. a port tuned to 30 hz with decent amount of port area will displace close to .5 cube, so after that, the volume the sub will see is down quite a bit. difference between 32 and 29........not a ton. 32 would be a little more boomy in the 35-50 range, and the frequency response wouldn't be as flat as the 29. but the difference would be pretty small. about finishing........it's up to you. I wouldn't spray paint, as I haven't had good luck with that. but if you use a regular paint and brush it on, you can yield pretty good results. I've never carpeted a box, though. i've either painted them or leave them bare (which is what I usually do).

hey not to steal your post, but I got my 15" yesterday. real excited (my first 15, and it's a monster!). gonna be two weeks prolly before I get it in the car, though. which sucks. haven't had time to build the box yet. You've got an all SI system, though. That's pretty sweet.

yeah I have a '91 cutlass supreme. our w-bodies really aren't meant for SPL. I'm not sure on his focus, though. take out rear speakers, and fold down the back seat if you can. that helps by a couple db.

Yeah they can get loud. don't underestimate them too much. though I would never pay 600 each for any. what vehicle does he have? what vehicle do you have?

yeah but 6" would still be wild to see, right? right? this sub still moves farther than any sub i've ever seen (no supersubs around here), so i'll be excited to see it.

whoa 6"? criminitely. I gotta try that when I get my 15 D2 in ! that's gonna be wild to see

unless you listen to some unique stuff, you won't ever get any frequencies below 30 hz. the lowest rap songs are usually around 35 hz. so unless you have some electronic music can go lower, or some organ stuff or something, you'll be fine w/out a subsonic.

I usually start around 80 hz, then adjust from there to see what sounds best. I think with my current JL XR 6.5's and my ED 12K's i have them crossed over at about 75 or so. Really I think I like to play my mids as far down as I can without them breaking up, because I think midbass sounds better out of my mids than my subs.

Wahoo! wait, so when will they be in? I'm confused

Also, you have to realize what frequency that box is ported to, and which tones were used. a box tuned to 46 hz is high and will be very peaky around 50 hz. above 60 and below tuning, it will drop quite a bit. Actually, seeing those numbers in the ported box below tuning still louder than the sealed box surprises me. A sub loses a lot of control below tuning frequency. The fact that it took a 30 hz tone with 2000 watts gives me great respect for this driver. but really, those numbers don't strike me as odd.

yeah, you knew it would be this long. Will probably be the end of june, too.

oooh, sending a money order for the 15D2 tomorrow! After it gets in, the real fun begins. building the box, hoping it fits, then sealing off the trunk. might end up sawing some metal off the front of my back deck so it doesn't obstruct the front of the sub or port. yippee

So I need some testimonials. I've read most of the threads related to them on here, I just want MORE! nah not too much. I've just gotta nut up and do it. I'm thinking about putting a 15D2 in a 3.0-3.5 cubic foot ported box, one tune to 32 hz or so, another to 45 or so. How much port area does this sub like? Also, I'm a fan of quick, tight bass. Will this setup deliver for me? I'm forward-facing it in my trunk, and sealing off behind it. I was just a little worried because the group delay is 2.5 times that of my current setup of four sealed flat cone ED 12K's. And the Le on the D2 seems high, but does it make a difference if the sub is wired in series or parallel? looks like in their specs they have it in series, so I was just wondering. Thanks to all who respond. except those who just like to post whore. you just suck

well looks like the 15" should be able to stand upright in there. it's very close, though, haha. and it looks like I'll end up with about 3.8 cubes and 40 square inches of port

oh yeah brass monkey i'd love to. problem is.....I live in Hays for the summer. And I was gonna do this project in the next month or two. so I wouldn't have my ED stuff when I got back, and I wouldn't be able to hear yours before I get back either. but afterwards if I have my 15D2, we can compare to your 12's. I also have JL XR's in front, but just the 2 way comps.

well this all sounds promising. thanks fellars. Now I just have to think of a box design. the opening to my trunk from behind my seat is only about 13" tall, though the back deck raises up a little behind it (has a lip on the front). not sure if it's tall enough, though, so I might have to slant the box a little. not really what i wanted to do at all.

Man I have to become a newbie again? I thought after 5 years in this game I'd get a little more credit than that

thanks for the response. I was kinda worried it would like a box closer to 4 cubes, but I'm worried because I think I can only fit about a 4 cube box before displacement. And if you say to try 50 sq. inches, that'll make for an awfully long port which'll displace quite a bit of my room. with my calculations, I may only be able to give it 35 or so. that would leave me with 3.5 cubes after displacement. I'm gonna power it with my Crossfire BMF 1000D, so it'll get 1000+ watts. oh, and i'm not too worried about the response graph winISD gives me. I was just worried about group delay and the semi-high Le of the driver affecting how tight it sounds. plus I don't know if facing forward helps or worsens the accuracy