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Old 30th December 2012, 09:09 PM   #221
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MA A6P
A6.2M might be a better choice for this enclosure.

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Old 30th December 2012, 09:12 PM   #222
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Chaz,
Those look great! It's going to work just fine.
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Old 30th December 2012, 09:18 PM   #223
xrk971 is online now xrk971  United States
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Wow, that is a great deal on those 16 ohm NS3's at $2.50!

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Old 30th December 2012, 09:26 PM   #224
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Wow, that is a great deal on those 16 ohm NS3's at $2.50!
I'm getting 100 for an EnABL trainee to practise on.

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Old 30th December 2012, 09:43 PM   #225
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I've been listening to my Cornu horn for about a week now. I built mine using the Elmers foam with the heavy paper backing for the front and back sheets. The inner spirals were made using the dollar store foam board. Size is 20" square with a 2.5" internal depth.

To draw the spirals I used a projector and projected the spiral onto the foamboard while it was taped to the wall and adjusted until it fit, then traced in pencil. Very fast and easy. I glued the inner spirals to the back using standard hot melt glue. My plan has always been to cover these with a cloth "sock" to make them decorative wall pieces. I knew that I had to recess the driver a bit and needed something for it to securely mount to, so I decided to use a piece of 1/4" craft plywood and some dowels to make a mount and support behind the driver. I made small rebates to align the dowels in the ply. I also chamfered the ply where it met the horn inlet. I used short pieces of bamboo skewers at the leading edge of the foam horn inlets to round over the edge. To score the foam, I used a roller paper cutter - it only cuts 1/16" deep and makes fast work of the scoring.

The back plywood piece was glued on with wood glue, as were all the wood pieces. The hole in the plywood was cut with a 76mm hole saw, as was the hole in the foam. Then I traced out the driver frame on the front and removed the top layer of paper and the foam to provide a small recess for the driver. The top was glued on with adhesive caulk - it's cheap, easy to apply, has about a half hour of working time, and fills gaps easily.

The sound? Not as good as the speakers below them, but darn good for 1/10th the price. There's definitely some peakiness that is noticeable, but the bass is impressive for a 3" speaker. Stuffing isn't optimal - four layers of felt behind the driver and as much polyfill as I could get in the chamber. I probably should have stuffed some of the line, but I was afraid of overstuffing and not being able to remove it. I do notice a lot of highs coming through the back, probably due to the lightweight materials.

I had a few leftover pieces of foamboard so I made a small craft project for my kids. This foam is good stuff.
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Old 30th December 2012, 09:44 PM   #226
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Nice work Chaz.

I must say I am worried about you doing the stuffing and closing up the box unless you do as xrk suggests and make sure you can change it if you have to. If you over stuff it, you lose the value of this cabinet. I would do it at the end and make a cup shape for the chamber and use a fork if you want to add some to the throats. Stuffing makes more difference than almost any cabinet, so you have to get it right or you may miss the magic.
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Old 30th December 2012, 09:47 PM   #227
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Quote:
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but I was afraid of overstuffing and not being able to remove it.
Great work too Fenris. Can't stress enough the importance of your statement.

Quote:
I had a few leftover pieces of foamboard so I made a small craft project for my kids. This foam is good stuff.
Good Daddy.
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Old 30th December 2012, 10:08 PM   #228
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Very nice work Fenris. I like what you did with the wood driver mount. It looks like you used the $10 buyout TB w3-881si and it sounds good. Awesome to hear. Lots of good tricks you mentioned like the roller cutter for scoring. I have some of that nice Elmers foam board too, looks like it works out well as a baffle. Thanks for sharing.
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Old 30th December 2012, 10:26 PM   #229
prezden is offline prezden  Canada
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Here is another project in the works. I'm a little hesitant to post my effort so far. It looks pretty shabby compared to the ones by chaz and fenris
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Old 30th December 2012, 11:00 PM   #230
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Hey, us Canadians... we stick together. Yours look just fine.
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