need port placement help.

[noobieman]

Hi, I have ordered 2 sundown e-10's an amp, wiring kit, and everything else I'll need.  It should arrive by thursday or friday. This is my first system, but I realized that I'm going to need a custom enclosure because just about none of the dual pre-fab 10 enclosures fit in the space I want.  So i've gotten the measurements figured out, and how much volume I'll need, including displacement of speakers and my center brace.    I'm going to be building the box tomorrow it's dimensions are 22.5 x 14 x 18  using 3/4" mdf.  now that ends up being 2.06776 cubic feet of volume after a double thick (1.5 inches) center wall brace completely sealing each side from the other, and the speaker displacement is all figured in. so this is where i run into trouble i need to have 16"^2 port area, and have each side ported and tuned to 32hz and according to the volume calculator for rectangular enclosures and the slot port calculator on the12volt.com for a port that is 2inches by 8inches in a box w/ 2.06776 cubic feet of space i need a 17 inch port length, and if that's the case i can't put the port on the front because the subs will be in the way due to the width of the box being as narrow as it is, so i have to put them on either the back or the sides, but i don't have 17 inches of length across the back for each side.   so is the 16"^2 of port area super necessary or should i try to make the box a little deeper, and then add some filling material (to compensate for the extra volume) and port it out of the back?  i don't know that i can port it out of the back as is because again the box being as narrow as it is, and not being so deep, 18 inches depth and a 17 inch long port that is 2 inches wide wouldn't fit because the sub would be in the way.  now maybe there is a super simple solution as far as design goes that i don't know about or havent figured out.  but i'd greatly appreciate somebody's insight with some experience  maybe i need to think up a different design for the box, or maybe not go with a slot port, i just really would like to get this figured out tonight so i can build my box tomorrow.  any help or comments will be greatly appreciated.  

My maximum dimensions are 22.5"W x 15"H x 24" Depth

Thanks for taking the time to read and respond!

[ckeeler11]

Why are you separating the box? if you did a common chamber and run port out the front it would make it alot easier. Running your numbers you might need more room, I come up with 1.9 cu.ft. tuned to 33.4 with port area of 21.8 (11.5 per ft.).

 

What amp?

[noobieman]

1 minute ago, ckeeler11 said:

Why are you separating the box? if you did a common chamber and run port out the front it would make it alot easier.

thanks for the response. i was just under the impression that it would sound better if each side was sealed (may have read some misinformation somewhere).  is there going to be a huge difference in quality or loudness if i do a common chamber? Also another option I have is I realized that the slot port is out of the question for two separate chambers, because i was doing the volume for the whole box, if you do the volume for one side the port length is 30+ inches hahaha. so i was thinking about going for a circular port after all which would only need to be 2 inches wide and 6.56 inches long  so if I went with the two separate chambers i could actually just use circular ports and vent them out the side.  but now i'm curious as to the differences in slotted and circular ports, which is louder and also the differences between a common chamber and two separate chambers.

[ShadeTreeMechanic]

The round ports you are thinking of are way too small. The main benefit of doing a common chamber box is to keep the port length reasonable. As you have found out, small chambers make it hard to keep the port inside the box.

Edit: back in the day we ran sealed boxes separate chamber so it would be easier to tell if a sub was blown. Lol

[noobieman]

27 minutes ago, ShadeTreeMechanic said:

The round ports you are thinking of are way too small. The main benefit of doing a common chamber box is to keep the port length reasonable. As you have found out, small chambers make it hard to keep the port inside the box.

Hey, thanks for the input.  You obviously know much more than I do, so I'll pick your brain for a moment if you don't mind.  You said that the round ports are way too small, do you mean not wide enough?  Because the calculator i was using said a 2 inch port diameter at 6.5 inches long in a 1.03 cu. ft. chamber would provide a tuning frequency of 32hz.  I did seem to come across the general consensus that the advantages of two separate chambers outweighs that of a common chamber, but that was only reading a couple different threads, not hours of research or anything, and even lesser experience.

EDIT: Which option is going to be louder, common chamber or separate? and if i go common chamber do I go for slotted or circle port?

[ShadeTreeMechanic]

Well let me start by saying welcome to SMD. I don't know what size port you will need exactly because part of it depends on the power you want to run. In order to avoid port noise, the air velocity needs to be kept below a certain speed. Basically the bigger the port the more air it can handle. My first choice would be slot port common chamber. This way the port size can be made exactly the right size. Although a port that is too big won't hurt output, it will make it difficult to fit in the box when tuned low. Both slot ports and round ports can turn and run along the back wall if needed. Your box sounds like it might be a little on the small side. Maybe someone who is familiar with that brand will chime in.

[noobieman]

19 minutes ago, ShadeTreeMechanic said:

Well let me start by saying welcome to SMD. I don't know what size port you will need exactly because part of it depends on the power you want to run. In order to avoid port noise, the air velocity needs to be kept below a certain speed. Basically the bigger the port the more air it can handle. My first choice would be slot port common chamber. This way the port size can be made exactly the right size. Although a port that is too big won't hurt output, it will make it difficult to fit in the box when tuned low. Both slot ports and round ports can turn and run along the back wall if needed. Your box sounds like it might be a little on the small side. Maybe someone who is familiar with that brand will chime in.

Thanks for the welcoming.  So the sundown website recommends ported enclosure size of 1 cu ft. and says there is a speaker displacement of .11 cu ft. i accounted for speaker displacement and the brace displacement, but i forgot port displacement, is that why you're questioning the size?  the brace is like .3 something or like .28 iirc and the total speaker displacement would be .22 that's where i came up with the 2.5 something cu ft total size, but i had forgotten about the port displacement, so i think it is a little on the small side if i went separate chambers if i go w/ the common chamber i may only need to make it a little bigger to account for the port displacement since i wouldn't have nearly as large of a brace.

Quote

1 hour ago, ckeeler11 said:

 

What amp?

sorry just saw this edit, i ordered the Skar audio skv2 1500.1, and you may be right on the 1.9 cu ft, i wasn't quite precise on my numbers.  so i would need to go a little bigger, but i do have like 6 inches of wiggle room on depth, so i think i can manage the extra volume.  i'm totally open to any and all suggestions on different box dimensions as long as it fits in the aforementioned maximum dimensions 

 

[ckeeler11]

adding a couple of inches to the depth would definitely get you to where you need to be. the port should be 12.5" tall by 3.0" wide. 39" will give you a tune of 34 Hz. total box volume would be 2.0

[Jessica]

22.5W X 14w X 18D or 22.5W x 14d and 18H? subs up, back, forward, down? port forward, side, up, down?

vehicle?

power?

 

[noobieman]

9 minutes ago, ckeeler11 said:

adding a couple of inches to the depth would definitely get you to where you need to be. the port should be 12.5" tall by 3.0" wide. 39" will give you a tune of 34 Hz. total box volume would be 2.0

okay so i'm about to go out to eat so i'll be gone for an hour or two but i'll be back with more questions.  currently i'd like to know how i could get a 39" port length w/ my dimensions. do i have to go w/ like an l shaped port some how or i'm not quite sure how that works.  as this is my first build i'm thinking simplicity is best.  how wide in diameter and long of a port would i need if i went with a single circular vent and a common chamber?  the sundown website recommends 32hz tuning and you're saying same width and height but 2 inches deeper?