Curved enclosures....

[gregnash]

Being an aesthetic person I like the look of curved enclosures compared to the straight side enclosures. However, how does one determine the necessary size increase when curving an enclosure?

[savage25xtreme]

when/if I ever do one I will use solidworks to calculate the internal volume for me. I wonder if there is any freeware you could model and have calculate the volume?

[numberoneoppa]

Err... basic calculus, anybody? :P

[john trials]

Draw a cross section of the proposed speaker enclosure on graph paper (1:1 scale will be easiest), and start counting squares to get the area. Multiply by the height to get volume (remember to subtract volumes for the driver, port, bracing, etc.)...adjust the size as necessary. If the curvature is circular (constant radius), then geometry can solve the problem. If you want to get really crazy, use calculus (I can't remember calculus, though...I'd use graph paper).

[Bear]

when/if I ever do one I will use solidworks to calculate the internal volume for me. I wonder if there is any freeware you could model and have calculate the volume?

http://sketchup.google.com

[NyxOne]

http://sketchup.google.com

... and use this plugin.

Chuck

[gregnash]

Ok thanks guys... With that said, if I create the straight sided box and calculate that given volume, should I then base the curved box on the same volume (usually given in the initial designs) and expand the depth/height/width where needed?

[cobblepots]

Sorry to hijack...

Along the curved enclosure lines, how would one go about flushing the curve of the sides to the back of the enclosure? I'm not thinking that a flush trim would work. I was thinking of using a table saw with the fence set up to the desired height and using a combination of belt sander and bondo to smooth it out. Thoughts?

[Biff]

it depends

If you can borrow a trim router from someone it will have a tilt base and you can do what is needed. A belt sander will do the trick also, without using the saw, maybe the bondo just to sharpen up that corner if needed.

[b_force]

Counting squares and using CAD software :P pfffff :smackbutt:

I ones had en great curve and integrated it.
Was a bit of a job (most say that Maple helped me a little bit), but it's real 8)

However, a really strange curve is a very difficult job, but that's also for CAD-software programs. (I don't use them, but from friends I know that there are some limits)

[HareBrained]

Err... basic calculus, anybody? :P

Geometry or trigonometry would be better. Integrating through a curve is only an approximation and far too complex for the "wrong" answer.

Of course, you don't have to know down to the exact cc. There are some many fudge factors used to calculate the "ideal" enclosure volume that it hardly seems worthwhile. For example, my cabinet 14.764L with 0.5lbs of stuffing and the walls are lined with 1" foam and 0.25" felt. So what is the volume seen be the driver?

I always exaggerate the dimensions after determining what the net volume needs to be. It's always easier to add bracing or shorten a port if the enclosure turns out significantly larger than the design called for.

[Bear]

Counting squares and using CAD software :P pfffff :smackbutt:

I ones had en great curve and integrated it.
Was a bit of a job (most say that Maple helped me a little bit), but it's real 8)

However, a really strange curve is a very difficult job, but that's also for CAD-software programs. (I don't use them, but from friends I know that there are some limits)

Sorry, Maple users are in the same floodplain with us CAD software guys. No high ground there. Software is software. :T

[gregnash]

Ok so I have been playing with sketch-up and got the volume of each item; a straight side tower and a curved tower. The difference is approximately 6.5L (74.332L v. 68.805L respectively), now here is how I came up with the curved tower.
1. Back plane to be approximately 5" wide (to allow for port and/or post plate)
2. Above makes cut in approximately 2" from side
3. connected front corner to back corner with arc tool
4. mid-point of arc met with mid mark of standard straight side cabinet (approximately 6")
This would give my arc a radius of 19 1/4" which is effectively a 15/64" push out for the curve... I tried to model it up as best I could.

[Not2Evil]

I would think the first thing to determine is the methodology of cutting, bending, or gluing of the material to achieve what you find asthetic.

Find a method and shape that works well for what you want to do (repeatable) , then make a small, medium, and large template of your desired shape out of some 3/4 MDF.

I'm all about math, but complex shapes are a pain. I believe I would take a router and make a duplicate of the above templates because what I'm about to suggest will ruin one set. Slap a cheap piece of hardboard on the bottom of the duplicates, and slather them with a thin coat of RTV.

After the RTV has cured for a day, pour cups of water in and see how much each one holds. Multiply times height, convert to liters, and voila, pick which of the three templates best fits.

[numberoneoppa]

You guys make it seem like integration is hard... :/

[Not2Evil]

You guys make it seem like integration is hard... :/

It's part of my life, but not all people pursue math. I was just offering an alternative.

Diversity seems to be a major buzz word these days.

[Dave Bullet]

Build a prototype, line it with plastic then see how much beer you can pour in. The beer is important, since when you are done measuring you'll have to drink it.

[b_force]

Sorry, Maple users are in the same floodplain with us CAD software guys. No high ground there. Software is software. :T

I only used it for fill in the integration/numbers (from A to B). Did the other work by hand.
CAD-software actually also count squares (pixels)

But I must agree with Not2Evil. Math and integration is a part of my study. However, complex shapes are indeed a great pain

And guys, watch on significance on your answers! :P
More than three digits after the comma ehm I mean dot (lol, so confusing in non-metric) is just frenzy.
Besides that, the T/S parameters aren't that precise.

[---k---]

I'm glad my wife is happy with square boxes painted black.

I admire all of you who take on these more difficult projects. I'm always amazed at how impressive the results are.

My lazy butt would probably buy like 6 PE curved boxes and cut the bottoms out of them and then use threaded rod to clamp the three together into one.

[savage25xtreme]

I'm glad my wife is happy with square boxes painted black.

I admire all of you who take on these more difficult projects. I'm always amazed at how impressive the results are.

My lazy butt would probably buy like 6 PE curved boxes and cut the bottoms out of them and then use threaded rod to clamp the three together into one.

the adventure is in the journey, not the destination

for those of us who are incapable of loud speaker design we must throw our own flavor of creativity at a project. at least the way I see it.

[b_force]

And in some creative designs there are even some great acoustic benefits

[gregnash]

And in some creative designs there are even some great acoustic benefits

:Visions of large waveguide ports at the top of a speaker: :E :banghead:

Wonder if you could do something like side slot ports that would sit around a specifically curved enclosure for bass resonance?