Old Timer in need of help

[1point21gigawatts]

1 minute ago, d luv said:

He’s currently at his Moms so I can’t measure sorry. I text him and he said the pre fab box he bought is BBox E12DSV and states is 1” thick wood with other dimensions of 30”W x 13.75”H x 17.25”D with a vent width of 2.75” and is a straight port and not an “L”  sorry, had L port on my mind as I thought the additional material would result in an L port. I would like to modify the current port but if you think I could make him another box of the similar outer dimensions that would sound much better than I am not against that either. I know he just doesn’t want to give up more cargo space though. Again thanks for you insight And help 

Now I understand why the measurements and graph was wrong. I do apologize. Wait until he gets home and do the measurements yourself, so you know they’re accurate and then post them. Measure the length of the inside pieces of wood that make the port so I know how long the port walls are. Measure the width and height of the port. And measure the width, height and depth of the enclosure. Because if it’s made of 1” wood then them measurements and graph are far off and the measurements don’t make sense. So make sure you check the thickness of the wood yourself. Then when you figure these measurements out then post them. Or just say, “Yo, my son has this brand and model of subwoofer and this type of car, can you design me an enclosure?” That would be better and easier. Because measuring the inside of an “L” formation port is almost impossible and will even piss off a priest. 

[1point21gigawatts]

I know that graph and you say that the enclosure is made of 1” wood, but it doesn’t make sense because there are errors in the graph. And on another note, that’s a small enclosure and it’s tuned high. What kind of vehicle does he have and what type of subwoofers are they? After subwoofer displacements then then enclosure is even smaller and that port is small. The port needs to be wider and the enclosure needs to be bigger. The tuning isn’t the biggest concern. I’ve used a 37hz enclosure before that sounded great but the enclosure was big and so was the port. 

[d luv]

6 minutes ago, 1point21gigawatts said:

Because if the thickness is 1” and the enclosure having a height of 13.25” then the port would be 11.25” in height. And if it were .75” then the port would have a height of 11.75”. Your graph is contradicting and so is the measurements you are telling me. I can’t help you if I don’t know what I’m working with. Even the graph above says the port height is the same as the enclosure height and that’s impossible. And it says the outer depth of the enclosure is 17.25” and the inner depth of the enclosure is 16.5”. The only way that’s possible is if the the wood thickness is 3/8” and if that’s so then he needed a new enclosure anyways because that wood would be too thin and would flex too much and take away from the output. I’ve heard of 5/8” enclosures for small builds but I’ve never heard of 3/8” enclosures. You need to post better information, more information and more accurate information. 

I asked him where he is getting his specs from and he sent me this link as apparently it is the same box as his https://www.amazon.com/gp/aw/d/B0013MYXDO?psc=1&ref=ppx_pop_mob_b_asin_title

 

From what I have read in the reviews it seems you are right and other people are saying the thickness is less than 1” as stated by the manufacturer and closer to 3/4”.

[d luv]

2 minutes ago, 1point21gigawatts said:

I know that graph and you say that the enclosure is made of 1” wood, but it doesn’t make sense because there are errors in the graph and that’s a small enclosure and tuned high. What kind of vehicle does he have and what type of subwoofers are they?

He has a Ford Explorer and his subs are 2 12 JLW7

[1point21gigawatts]

4 minutes ago, 1point21gigawatts said:

I know that graph and you say that the enclosure is made of 1” wood, but it doesn’t make sense because there are errors in the graph. And on another note, that’s a small enclosure and it’s tuned high. What kind of vehicle does he have and what type of subwoofers are they? After subwoofer displacements then then enclosure is even smaller and that port is small. The port needs to be wider and the enclosure needs to be bigger. The tuning isn’t the biggest concern. I’ve used a 37hz enclosure before that sounded great but the enclosure was big and so was the port. 

Edited to add to my most recent post. 

[Joshdashef]

56 minutes ago, d luv said:

He is running 2 12 JL W7’s on an older 2000watt rms Hifonics D class amp, Brutus maybe but I may be wrong on the model. 

Way I see it is you have three options.

1. Add wood to lengthen the inside of the port.

• Downside is you will have to make an L shaped piece and hope it fits into the sub cutouts or piece it together inside the box. PITA if you ask me

2. Extend the port outside of the box, keeping the internal volume the same, but you will achieve a lower tuning frequency by simply lengthening the port outside the box.

• Downside is it requires space, something you mention you are limited on, and its kinda fugly but will get the job done.
• Upside is it is much easier and more forgiving to get to your desire tuning.

3. All new box.

• Real easy to pull off and gets you much better sound for the money. Single sheet of 3/4" mdf or so will get it done. What music does he listen to mostly? Hip-hop/rap? 

 

5 minutes ago, d luv said:

I asked him where he is getting his specs from and he sent me this link as apparently it is the same box as his https://www.amazon.com/gp/aw/d/B0013MYXDO?psc=1&ref=ppx_pop_mob_b_asin_title

 

From what I have read in the reviews it seems you are right and other people are saying the thickness is less than 1” as stated by the manufacturer and closer to 3/4”.

From what I see of that amazon ad that box is 1" front baffle and 3/4" the rest of the box. 

[1point21gigawatts]

5 minutes ago, d luv said:

He has a Ford Explorer and his subs are 2 12 JLW7

That is a car audio crime to put them subwoofers in that enclosure. Lol! You have to buy or build another enclosure. If you want to just buy one to make it easier, let me know. If you want to build one, let me know. Either way, I can point you in the right direction on either choice. I can design you an enclosure for them subwoofers that once he sees it and hears it, it will make him excited like a little kid and he will give you the same look that he use to give you on Christmas morning when he was real young. Or if you don’t want to or aren’t able to build him an enclosure then I can post a link to a good prefab enclosure but it will be expensive. It will make him just as happy and he will still make the same look towards you. Y’all both will love it. Them subwoofers are expensive, why did he cheap out on the enclosure?

[d luv]

5 minutes ago, Joshdashef said:

Way I see it is you have three options.

1. Add wood to lengthen the inside of the port.

• Downside is you will have to make an L shaped piece and hope it fits into the sub cutouts or piece it together inside the box. PITA if you ask me

2. Extend the port outside of the box, keeping the internal volume the same, but you will achieve a lower tuning frequency by simply lengthening the port outside the box.

• Downside is it requires space, something you mention you are limited on, and its kinda fugly but will get the job done.
• Upside is it is much easier and more forgiving to get to your desire tuning.

3. All new box.

• Real easy to pull off and gets you much better sound for the money. Single sheet of 3/4" mdf or so will get it done. What music does he listen to mostly? Hip-hop/rap? 

 

From what I see of that amazon ad that box is 1" front baffle and 3/4" the rest of the box. 

He listens to mostly rap (no idea who) but also some older rock (Pantera/Rage Against the Machine). I know I have a sheet of MDF in my garage rafters, 1” thick. 

[1point21gigawatts]

JL w7 12” subwoofers call for about 37hz, so the 39hz tuning isn’t the problem. After looking at the enclosure specifications for that subwoofer, it’s like I though, there isn’t enough port area, meaning the port has to be wider and/or taller, preferably wider to lower port velocity to lessen the chance of port noise, and that enclosure is too small. So like I said, the enclosure is too small and the port is too small. There’s nothing you can do but get another enclosure. 

[d luv]

2 minutes ago, 1point21gigawatts said:

JL w7 12” subwoofers call for about 37hz, so the 39hz tuning isn’t the problem. After looking at the enclosure specifications for that subwoofer, it’s like I though, there isn’t enough port area, meaning the port has to be wider and/or taller, preferably wider to lower port velocity to lessen the chance of port noise, and that enclosure is too small. So like I said, the enclosure is too small and the port is too small. There’s nothing you can do but get another enclosure. 

Ok in the other post you mentioned a design and cut sheet, do you have something you would recommend? He won’t be competing or anything just wants more out of his daily driver.