Need Help

[cww180 10+ year member]

I would like help with designing a ported box for a single 15" AA Havoc that will be installed in trunk of my 2001 Honda Civic Ferio. I listed to mostly rap/hip hop/R&B. The max width I have is 36", the max height is 17", and I would like to keep the depth to whatever is necessary for the sub to perform well. Any help is appreciated.

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[altoncustomtech 10+ year member]

Well.... Ascendant recommends 3-5cuft.... picking 4cuft as optimum I tuned the box to 32hz since these are often compared to Fi's Q subwoofers and that is the optimum tuning for those... and fit it to your 36" wide by 17" tall requirements.... see if this is may work for you...

The port width is a little fuzzy... it sez 4.129".... u can use 4.125 or 4 1/8" easy.... the length of the sides says 17.580 which can be 17.5625 or 17 9/16".... etc... as you can see any side that's a funny decimal can easily be rounded up or down a bit to an equivalent fraction...

 

[PV Audio 5,000+ posts]

^^ Those errors will add up. No one can cut something to x.33" wide unless they have a precision tool without a saw blade.

 

[marcotheclepto 10+ year member]

^^ Those errors will add up. No one can cut something to x.33" wide unless they have a precision tool without a saw blade.

i think i was talking to the same guy last night... about same issue...

 

[PV Audio 5,000+ posts]

Not surprised. That's the problem with online calculators and spreadsheets: if they don't snap to the nearest 1/16, then they are hard to use because a 1/16" / 1/32" gap on 4 panels adds up. Quickly.

 

[altoncustomtech 10+ year member]

okay, okay...... it's not ideal..... while the spreadsheet CAN snap to the nearest 16th of an inch the thing that cannot be controlled is whether or not it snaps up or down.... that problem in itself makes it difficult... however, there's several books out there written on enclosure design theory and practice that say even a ported enclosure can be off by no more than 10% and not cause a noticeable affect in the sound to the ear..... most of them also say to err on the high side cuz you can add wood to the inside to bring the size down... that being said, what does it hurt to have numbers that cannot be utilized easily? Some simple math and paying attention to what your doing can easily yield numbers that are usable.....

Now I will submit to the fact that jumping in that quick with numbers like this to someone who is new to the game and most likely not used to working with the numbers and rules of enclosure building wasn't the best idea, I can definitely see that now and I appoligize to the OP for giving information in the design that could be difficult to follow AND for causing his thread to get jacked and go off in this discussion.

 

[PV Audio 5,000+ posts]

okay, okay...... it's not ideal..... while the spreadsheet CAN snap to the nearest 16th of an inch the thing that cannot be controlled is whether or not it snaps up or down.... that problem in itself makes it difficult... however, there's several books out there written on enclosure design theory and practice that say even a ported enclosure can be off by no more than 10% and not cause a noticeable affect in the sound to the ear..... most of them also say to err on the high side cuz you can add wood to the inside to bring the size down... that being said, what does it hurt to have numbers that cannot be utilized easily? Some simple math and paying attention to what your doing can easily yield numbers that are usable.....
Now I will submit to the fact that jumping in that quick with numbers like this to someone who is new to the game and most likely not used to working with the numbers and rules of enclosure building wasn't the best idea, I can definitely see that now and I appoligize to the OP for giving information in the design that could be difficult to follow AND for causing his thread to get jacked and go off in this discussion.

It's fine, no one is stealing your thunder. I was just commenting that using spreadsheets and programs without user intuition is useless regardless of how flawless the design might be. Therefore, the OP should take your design since it's what he needs, but he'll need to make sure all the dimensions fit.

 

[altoncustomtech 10+ year member]

It's fine, no one is stealing your thunder. I was just commenting that using spreadsheets and programs without user intuition is useless regardless of how flawless the design might be. Therefore, the OP should take your design since it's what he needs, but he'll need to make sure all the dimensions fit.

Thanks.... sorry for the rant.... just wanted to clear up that I knew that the numbers weren't cut ready and that it would probably be best to clean the numbers up to cut ready dimensions before posting up for someone.... something I will practice hence forth....

And to the OP.... Again.... Sorry, we keep jackin' around here.

 

[cww180 10+ year member]

No problem guys, I'm assuming I should do a baffle for the woofer. In a trunk design should the sub and port be on the same panel?

 

[cww180 10+ year member]

Would the calculator be more accurate if the metric system was used? Is that a possibility?

 

[altoncustomtech 10+ year member]

more accurate yes..... but around here most all the tools are English standard.... tablesaws, tape measures, carpenter's squares are all english standard and any attempt at the conversion from metric back would have the same problems.... the best answer is to do a little more work and make sure the cut measurements come out to numbers that line directly up with the common fractions.... or buy a CNC...