Dayton CX150-8 Coaxial Project

[JavadS]

Nice work Bill and great idea on the sanding fixtures, love that!

[4thtry]

Nice work Bill and great idea on the sanding fixtures, love that!

Thanks Javad! Took me a while to build them, but they worked great. My next one will be a "custom-curved-cabinet-clamping" fixture. Sure hope it works as good as the sanding fixtures.

[4thtry]

I used my router and a flush trim bit to duplicate the template several times:





When done, I had six identical baffle & back panels. I also had six almost identical remnant panels, as can be seen in the background. I plan to attach a back bracing panel to three of these remnants so that I can use the resulting assembly as a custom clamping fixture.





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[scottvalentin]

Great tip to use the router looks like they turned out perfect!

[emilime75]

I removed the paper template and carpet tape from the particle board immediately after the cut. As you can see, it stuck to the paper and pulled off cleanly from the particle board. I was a little concerned that the carpet tape would stick too tightly to the particle board when I pulled it up. But this didn't happen.

Any time I'm concerned about this I lay down some blue painter's tape first.

[emilime75]

Just came across this in another forum...it appears that the vented voice coil on the coaxial is a direct air path between the interior and exterior when in a cabinet. In other words, an air leak around the tweeter.

[tomzarbo]

Looks good Bill.

How do you like particle board to work with compared to MDF. It's a lot nicer, right? I need to use it more often, it doesn't make dust like MDF and it doesn't smell so funny.

I like the idea of using the scraps to make a clamping fixture, great call there. Not sure if I did that or not on any of my projects, but I probably should have if I didn't!

TomZ

[Wolf]

Just came across this in another forum...it appears that the vented voice coil on the coaxial is a direct air path between the interior and exterior when in a cabinet. In other words, an air leak around the tweeter.

That was for the 4". Is it a vented former on the 5" too?

Later,
Wolf

[emilime75]

That was for the 4". Is it a vented former on the 5" too?

Later,
Wolf

Not sure, I just assumed since both are from the same line, so I could be wrong. PE photos aren't much help. Maybe 4thtry could verify?

[JavadS]

Looks good Bill.

How do you like particle board to work with compared to MDF. It's a lot nicer, right? I need to use it more often, it doesn't make dust like MDF and it doesn't smell so funny.

I like the idea of using the scraps to make a clamping fixture, great call there. Not sure if I did that or not on any of my projects, but I probably should have if I didn't!

TomZ

It's all I used when I was a kid doing speaker building, but I remember it was pretty crumbly, MDF holds a very sharp edge and is very machinable (though it's weak as heck if you bump or hit it), the dust is horrible though which is why I'm a plywood and solid wood guy for the most part these days. I noticed Bill is good with the bondo though, interested to hear your thoughts Bill.

[1100xxben]

Bill, I think you'll be surprised how much stronger a laminated, curved side is. I built a pair of stentorians a few years back and used 6 layers of 1/8" HDF on the sides. In hind-sight, I could have easily gone with 3-4 layers and the cabinets would have been significantly lighter and the side walls would have been more than stiff enough. Of course you're more than welcome to use 6 layers, but I'm just letting you know that I don't think it will be necessary to go with that many.

Also, I built a "Dr. Seuss" bookshelf for my sister recently and made the curved sides with 3 layers of 1/8" hardboard, just like you're doing. I scuffed each layer by hitting it quickly with some 40 or 60 grit on the random orbit sander, just to take the shine off the smooth faces and make sure the glue has a chance to soak in. I used Titebond Extend wood glue, which has an extended working time for applications such as this. When I made my forms for gluing/clamping, I put some weather-stripping on the edge and left the paper attached to the "outside" of the weather stripping. This gave a smooth surface that would flex a little as it gets clamped down. Otherwise, as you add layers, your curve actually changes shape slightly and you're no longer applying clamping force to all the areas necessary. The weather-stripping helps keep clamping force on the entire area. It's not a perfect solution, but it works better than just using the cutoff piece as your clamping surface. For some reason I chose to use weight, which was barely enough. If I build another, I'll use ratchet straps.

Attached are a few pics of my jig setup, but you cannot see the weather-stripping in these pictures. If you want to see it, I can take pictures tonight that show the detail of the weather stripping. Even though it's not speaker building, I might make an OT post on that bookshelf and show how I went about it, because some of the techniques I used are applicable to curved cabinets, and sometimes it's always fun to see a wood-working project other than a speaker box

[4thtry]

Time for some glue-up:



I dry fitted the top panel in place to measure the bevel. An edge bevel of 17.8 degrees was required to match the curved side panel at this point:

[4thtry]

I added an angled partition near the top to divide the cabinet into an upper 0.25 cu.ft. sealed box for the midrange and a lower 1.7 cu ft vented box for the woofer. I positioned this partition at an angle, beveling the inside edge at 17.8 degrees, so that all midrange cabinet walls, except the front & back, became non-parallel. And the front & back parallel surfaces are broken up by the midrange magnet & basket assembly.

[4thtry]

Great tip to use the router looks like they turned out perfect!

Thanks. Almost perfect: there are a few small glitches here and there that you cannot see. The flush trim bit does a great job matching panels!

[4thtry]

Any time I'm concerned about this I lay down some blue painter's tape first.

Thanks. Another great tip. I'll try to remember this on my next project.