is this box calc accurate?

[DBfan187 5,000+ posts]

It won't let me make my height any bigger than 29".

I want my width to be 42" but it puts 32.5" instead. WTF???

 

[beerman 10+ year member]

It won't let me make my height any bigger than 29".
I want my width to be 42" but it puts 32.5" instead. WTF???

It can't make the port fit at 42", so it narrows it until it can.

At 42" wide (and with your specific enclosure volume, box height and tuning frequency), the violet panel is either coming up negative (in the case of an L-port) or the violet panel is longer than the teal panel(s) (in the case of making an accordian port) at anything wider than 32.5".

I don't understand why it won't let you go bigger than 29". Gimme more information. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[beerman 10+ year member]

So what do you have in store for v3 that is new?

Out: I was going to add a double-baffle option, but it won't work the way I originally intended. I have to change boatloads of code for it to work properly. So that's out for V3. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

In: user-inputs port area as opposed to a high-spl option. People are asking for flexibility.

In: help newbies make box design decisions. Input t/s parameters, spit out maximally flat alignment. User can also select a compact alignment that stays relatively flat (only +1.25db over flat) , but makes a smaller, higher-tuned enclosure. The emails asking "what box for this woofer" are starting to increase. Gotta automate myself out of volunteer work. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Possible: Front View, including woofer and port placement, along with magnet assemblies inside the box. This will require that I ask for woofer diameter/shape and the number of woofers. (That's quite a bit of work, that's why it's only "possible".)

Possible: help users determine where they should tune a woofer for a specific volume based on T/S parameters. Not much work, but not much value, either.

Possible: minimum port area based on cone excursion x cone area (assuring user that port velocity will never exceed 17m/s). This requires more input on the part of the end user, but will result in a smoother response at high SPL.

 

[DBfan187 5,000+ posts]

It can't make the port fit at 42", so it narrows it until it can.
At 42" wide (and with your specific enclosure volume, box height and tuning frequency), the violet panel is either coming up negative (in the case of an L-port) or the violet panel is longer than the teal panel(s) (in the case of making an accordian port) at anything wider than 32.5".

I don't understand why it won't let you go bigger than 29". Gimme more information. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Say I wanted to wall off my jeep.
I have 36"H x 42"W x 34"D.

It won't let me try that one.

 

[StreetSide]

Could you explain wich panel is wich like is red the side panel is blackthe front panel and so on.

 

[beerman 10+ year member]

Say I wanted to wall off my jeep.
I have 36"H x 42"W x 34"D.

It won't let me try that one.

How large of an enclosure? Tuning frequency?

 

[beerman 10+ year member]

Could you explain wich panel is wich like is red the side panel is blackthe front panel and so on.

Red is the speaker baffle. Black is the back. Teal/violet are the inner walls of the port. Yellow and green are the sides of the box.

 

[DBfan187 5,000+ posts]

How large of an enclosure? Tuning frequency?

13.04cF, 31Hz

 

[beerman 10+ year member]

13.04cF, 31Hz

Net Volume: 13 cubic feet

Tuning Frequency: 31 Hz

Port Width: 5.75 inches

Port Area: 198.375 Square Inches

Port Length: 31.25 inches

External Dimensions: 42 wide x 36 tall x 23.75 deep.

Board Dimensions and Quantity

Color Count Width Height

Top and Bottom 2 42 inches 23.75 inches

Red 1 35.5 inches 34.5 inches

Yellow 1 23 inches 34.5 inches

Black 1 40.5 inches 34.5 inches

Green 1 23.75 inches 34.5 inches

Teal 1 16.5 inches 34.5 inches

Violet 1 6 inches 34.5 inches

Number of 49x97 Sheets of 3/4" MDF: 1.5

I included a driver displacement of 1 cubic feet.

 

[Goldtaz1 10+ year member]

Does the calculator take "end correction factor" into account?? When I put in my numbers for my enclosure it didn't. End correction factor is usually calculated as 1/2 of the width added to the original port lenth.

 

[Goldenknob 10+ year member]

is it possible to make it able to calculate truck wedge boxes? ported?

 

[beerman 10+ year member]

End correction factor is usually calculated as 1/2 of the width added to the original port lenth.

You're thinking about it backwards.

Since the outer wall of the box is the outer wall of the port, it tends to lengthen the port beyond the inner port wall. To correct, you remove half a port width from the inner port.

http://www.jlaudio.com/tutorials/ports/index.html

An end correction factor is necesary because more often than not, one wall of the port is also one wall of the enclosure and this wall extends beyond the end of the port thus effectively adding length to the port

One has to remove that length from the inner port wall.

 

[beerman 10+ year member]

is it possible to make it able to calculate truck wedge boxes? ported?

That requires a bit more coding and the use of round ports since I don't have neat squares to work with.

 

[beerman 10+ year member]

Updated.

 

[Logikalliquid 10+ year member]

Updated.

I like it!//content.invisioncic.com/y282845/emoticons/thumbsupwink.gif.129404938effda6ad9cca39e7f4b58a3.gif