Joe X. Help please with the box you designed for me!

[Syphlyn]

I'm having some concerns about the box you designed for me earlier.

I did switch the depth and width labels as they were mixed up in the diagram. The original http://www.stevemeadedesigns.com/board/topic/189451-got-my-box-design-and-some-neat-paint-pictureswill-it-work/?p=2828129 you posted, you stated 18 inch depth but only put 17 in the diagram/parts. I assumed you accidentally put 17 inches for depth and 18 for width in the plans, so I edited and fixed it. Here are the FIXED plans (depth/width corrected)

I've been having thoughts about the port and how it fires. I've been told it should be loading off something and that a design like the original, I could end up losing some dbs. If that's the case I might have came up with a solution, maybe you'll have one that's better.

I moved the port to the bottom of the box facing the passenger rear door. There's about 3-4 inches of clearance between the port and the door, probably closer to 3. The inner port length is the same, the height of the port changed from 15.5 to 16.5 as it now runs along the depth of the box rather then the width. To accommodate for the taller port I've went from a box height of 26.375 to 27 inches. There is 6.5 inches of clearance between the top of the port wall (purple) and the top of the box ACCORDING TO MY CALCULATIONS. Hopefully this isn't as issue as far as the opening of the port on the interior of the box.

My calculations show the first port wall is 15.25 inches long, while the second is 17.25.

Which way will perform better? Some people say stay with the original design the port loads off the roof while others tell me to do the second design because it'll load off the door.

Any ideas/suggestions?

My max demensions are still: W: 17 | D: 18 | H: 26 or so

[Joe X]

Answering on PM.

[Hugh G. Rection]

wow, you could get nearly enough port delay to correct for the quarter wave theory.

[Syphlyn]

wow, you could get nearly enough port delay to correct for the quarter wave theory.

That sounds way beyond my knowledge, care to explain ?

[Hugh G. Rection]

wow, you could get nearly enough port delay to correct for the quarter wave theory.

That sounds way beyond my knowledge, care to explain ?

port work by having a moving mass of air that moves in phase with the woofer at a certain frequency. this is what tunes the box. it is a derivative of the ratio of port area, port length, internal volume of the enclosure, and of course many other things that all have to jive. at extremely long lengths, which the aforementioned port is, you run into problems with the moving mass of air moving efficiently. this is why most of the time when you see ported enclosures, most people work within a 12"-20" port length.

[Syphlyn]

wow, you could get nearly enough port delay to correct for the quarter wave theory.

That sounds way beyond my knowledge, care to explain ?

port work by having a moving mass of air that moves in phase with the woofer at a certain frequency. this is what tunes the box. it is a derivative of the ratio of port area, port length, internal volume of the enclosure, and of course many other things that all have to jive. at extremely long lengths, which the aforementioned port is, you run into problems with the moving mass of air moving efficiently. this is why most of the time when you see ported enclosures, most people work within a 12"-20" port length.

So this box isn't ideal then or what? Will it sound like shit?

[Hugh G. Rection]

wow, you could get nearly enough port delay to correct for the quarter wave theory.

That sounds way beyond my knowledge, care to explain ?

port work by having a moving mass of air that moves in phase with the woofer at a certain frequency. this is what tunes the box. it is a derivative of the ratio of port area, port length, internal volume of the enclosure, and of course many other things that all have to jive. at extremely long lengths, which the aforementioned port is, you run into problems with the moving mass of air moving efficiently. this is why most of the time when you see ported enclosures, most people work within a 12"-20" port length.

So this box isn't ideal then or what? Will it sound like shit?

i cant tell you how it will sound as this is greatly dependent on the environment it is in. it is not a design i would build personally, but i am quite particular about the design process of an enclosure. i tend to spend a couple hours working on a design, and only design for vehicles i have on hand because i have an extensive process of analysis i do on the vehicle before i even begin to design the enclosure.

i like to know what im working with, because whether you believe it or not, it does matter. any knowledgeable and credible designer will tell you that.

[Syphlyn]

i cant tell you how it will sound as this is greatly dependent on the environment it is in. it is not a design i would build personally, but i am quite particular about the design process of an enclosure. i tend to spend a couple hours working on a design, and only design for vehicles i have on hand because i have an extensive process of analysis i do on the vehicle before i even begin to design the enclosure.

So this box isn't ideal then or what? Will it sound like shit?

i like to know what im working with, because whether you believe it or not, it does matter. any knowledgeable and credible designer will tell you that.

Yeah it's a 2000 f150 ext cab. Kinda hard to find room in there, already removed the smaller seat.