Foam Core Board Speaker Enclosures?

And just in case anyone doesn't have a copy shop that is nearby (like me -- I am in the no man's land of large sheet copy places). When I am alone and have spare time, I rasterbate...

That didn't come out right.

I am using an old and trusty program called the "Rasterbator". It is pretty good and very cool, input your jpeg image and select your output size. It spits out a single .pdf file that when you print on your printer, prints it as tight to the edge as your printer allows, it then collates the pages, and you just have to tile them like so and add tape.

You can get it here:

The Rasterbator 1.2 at arje.net

You can also read about it on Wikipedia and google it to make sure you are within the system requirements (and that you aren't downloading malware of some sorts).
 
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Cal,
Your wood facers look awesome though. Home Depot has sheets of acrylic (1/8 in thick I think) but size is 24 x 24 in. You may need to contact place that fabs custom acrylic display cases and they get you a sheet of quarter inch for next build. Clear on both sides for window mount. A see through window speaker... Heck, make the faces out of glass! Fragile but would work well I bet. :)
 

6L6

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The other horn coming along, it took about 1.5hr from a bare board to here -

Layout is quite fast once you have holes in the paper. :) I wish I figured that out on the first one. Yes, this spiral is mirrored from the first.

Cornu10.jpg


Cornu9.jpg
 
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iko

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Joined 2008
I've played around with the simulation and things change quite a lot with a few changes in the horn definition (number of horn segments or segment area). At this point I don't trust this simulation but I'll trust an spl measurement. Cal, are you equipped for such a thing?
 
i know its no Cornu, but still foam core. heres my box 98% finished still waiting on the little chip amp to arrive from china. totally shoulda bought a few at $3.50 each...

its a thin marine carpet in the mouth, helps to attenuate the midbass frequencies.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


and a short vid off my phone for XRK

20121211_193632.mp4 video by klampykixx | Photobucket


on a different note, if im considering making a pair of cornu's to house a 6x9 car speaker each, i really need to pick a speaker thats brighter sounding yes? otherwise its gonna end up bassy as anything and otherwise dull? i really need to measure the specs of my drivers... alpine are hopeless... they emailed me back and dont have the spec on any of the lower class drivers..
 
I mean put the carbon paper on foam core board or wood panel, then put paper with spiral drawing on top, then just redraw spiral with pen, with little pushing.
Spiral is copied on board perfectly, without holes in paper.

I use this technique as a child, using for drawing copy:)
 
klampykixx,
I pondered producing an AkAbak model for your design, it's quite complex - a combination of tapped horn and back-loaded horn. Do you have T-S parameters for the drivers?

I've also considered a "Bose Wave Radio" design, with two small front facing full-range drivers. One has a relatively small sealed enclosure behind, the other has a back-loaded horn. Having only one driver with a horn allows a longer horn (therefore deeper bass) in a given space. It works, even with the tiny drivers, because the listening distance for a clock radio is usually only a couple of feet.

It would be a perfect candidate for building with 1/8" foam board for the internal walls. it could be used with an iPhone or similar providing the "clock radio" functions. The horn path could be "serpentine", like yours, or a Cornu-type spiral but reversed - spiral inwards, rather than outwards, with an exit through a hole in the centre of the bottom plate. The whole thing would be supported on feet so that the gap between the bottom plate and the table-top would form the final expansion of the horn. (This expansion can be set to any desired rate by filling in part of the space.) And finally, because the (white) foam board is somewhat translucent, you could fit internal LED lights to make it into a night light...

Run it off a small plug pack supply, add a signal-operated switch (senses the audio signal, turns on a MOSFET to supply power to the amp and LEDs).
 
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Don Hills,
I like your reverse spiral horn clock radio. I think the old Bose gen 1 had only a serpentine path on 1 driver and they went to 2 on later generations exiting a single common port like Klampy's. Are you thinking 2 in drivers or 3 inchers? The TB W3 881si for $10 ea comes to mind.... The led's with auto mosfet is a really good idea too. Do you have a schematic for that? I just had a thought, if the spirals are relatively thin, stack two one fires up and the other down, or they could both fire to common down port?
Xrk971
 
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6L6

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6L6, You have some really nice curves

Lol. :D :D :D


Is the black stuff the same as the Dollar Store white foam core? It looks really nice and thick facing paper.

It's the same junky stuff from the dollar store, just black. But it is easy to work with! I actually decided not to use the sheet of 'good' foamcore because it will be much harder to bend.

Also, a bit of PVA in the scores once the hot glue is set is making the curves much more solid.


Did you power up the first one with a driver yet?

I don't have a face on it. I need a tube of liquid nails.