Dayton CX150-8 Coaxial Project

[jhollander]

Thanks for the clarification, John. So you are talking about the directivity pattern with respect to frequency set up by the open baffle dimensions. But as Kevin pointed out, the 2k crossover is too low. I am looking at a minimum of 3.5K at 12dB/octave.

Yes that would be a risk and probably the best reason not to do OB. However you might throw a single cap on the tweeter and listen to it to see if it sounds decent crossed low. You can also compromise on the constant directivity and cross it above where the distortion starts to climb.

[Mike220]

Have you looked into bending plywood? We have some in illinois available called "Luan bending plywood" i think it goes up to 3/8" or 1/2" thick it would save a few laminations. Its really flexible for sure.

Lastly, how high do you think you could cross that paper 10" driver? You think it could make it to 1000-1400hz range?

[4thtry]

Here is a pic of my full scale cutting templates (printed in b/w draft mode at Fed Ex). I initially printed both baffles the same, but the double, side by side, asymmetry didn't look right to my eyes. So I clicked the "flip horizontal" function in photoshop and then re-printed one as a mirror image of the other. With this change, I think that they look much better when set up as a stereo pair for listening.

[4thtry]

Menards has 1/8 mdf if you have one nearby.

Thanks. Found them. And available in inexpensive handy panels too!

[4thtry]

Have you looked into bending plywood? We have some in illinois available called "Luan bending plywood" i think it goes up to 3/8" or 1/2" thick it would save a few laminations. Its really flexible for sure.

Lastly, how high do you think you could cross that paper 10" driver? You think it could make it to 1000-1400hz range?

No, but I definitely will. Thanks for the tip.

This is my first time using the RS270P-8 paper cone, so not sure about a higher xover point. My guess, looking at the spec sheet and FR graph, is that 1000-1400Hz would be just fine. My reason for crossing at 400Hz is because the CX150-8 can easily go this low and should sound better in this range.

[Mike220]

Ok thanks. I was asking for a personal 2way build waveguide build. Trying to find an 8" or 10" thats reasonably price and can cross approximately there.

[emilime75]

Do you own a router? If not, you may want to consider buying one. With a router and a flush trim bit, you can cut just one of those curvy panels, sand it and work it until it's exactly to your liking and then use it as a template to make 3 more identical pieces.

[4thtry]

Do you own a router? If not, you may want to consider buying one. With a router and a flush trim bit, you can cut just one of those curvy panels, sand it and work it until it's exactly to your liking and then use it as a template to make 3 more identical pieces.

Thanks for the excellent tip! Yes I do. And I also have a flush trim bit. I was going to make each cut individually by hand and I was worried about getting a good match from side to side. This technique will solve that problem completely.

And good timing too, as I am just getting ready to make these cuts!

[emilime75]

Excellent, that should make things much easier...well, you'll still have to make the curved sides, which in itself will be a challenge with the curve changing direction. Can't just wrap ratchet straps around it. Any thoughts on how you plan on tackling that?

Looks like it will take a lot of clamps, and starting in the center, at the narrowest point and working outwards(up/down) would be the best method...but then you start running into problems with the clamps being at an angle to the straight edge of the straight side of the baffle. You may want to consider making this a dual baffle design, with the inner one cut into a curvy window brace of sorts, the cutouts shaped to follow the curve, this way wherever you put a clamp, it will be perpendicular to the curved side and not slide around on you. Do the same for the back. Once you're done laminating the curved side, trim it flush, add a solid rear and front baffle to extend over the laminated sides, then flushtrim again. These braces/inner baffles can be .5" or .75" MDF or plywood, and will help strengthen the whole enclosure. Hope all that makes sense, and sorry if this is all things you already know.

[4thtry]

Excellent, that should make things much easier...well, you'll still have to make the curved sides, which in itself will be a challenge with the curve changing direction. Can't just wrap ratchet straps around it. Any thoughts on how you plan on tackling that?

Looks like it will take a lot of clamps, and starting in the center, at the narrowest point and working outwards(up/down) would be the best method...but then you start running into problems with the clamps being at an angle to the straight edge of the straight side of the baffle. You may want to consider making this a dual baffle design, with the inner one cut into a curvy window brace of sorts, the cutouts shaped to follow the curve, this way wherever you put a clamp, it will be perpendicular to the curved side and not slide around on you. Do the same for the back. Once you're done laminating the curved side, trim it flush, add a solid rear and front baffle to extend over the laminated sides, then flushtrim again. These braces/inner baffles can be .5" or .75" MDF or plywood, and will help strengthen the whole enclosure. Hope all that makes sense, and sorry if this is all things you already know.

Since this will be my first time putting a curved cab together, I was going to copy the procedure that Tom Z used on his "DN-10" and "Classic Tension Headache" speakers. Basically, he used a large number of bar clamps and a series of angled blocks to keep the clamps from sliding around. He also made his panels slightly oversized and then flush trimmed them later, as you suggest. I will also be using 1/8" instead of 1/4" thick MDF to create my laminated side panels, as suggested by Ugly Woofer above. This should make it easier to clamp in place.

Thanks again for all the excellent suggestions. Keep them coming!

Bill

[4thtry]

I had my local big box lumber yard slice up a couple 4x8 sheets of 3/4" particle board and 1/8" MDF down to 16 inch widths to fit my hatchback. I'm now ready to make some serious sawdust!

[ani_101]

Is that 1/8 MDF or HDF Tempred Board (Hardboard) - smooth on one side and a bit rough on the other

[JavadS]

I had my local big box lumber yard slice up a couple 4x8 sheets of 3/4" particle board and 1/8" MDF down to 16 inch widths to fit my hatchback. I'm now ready to make some serious sawdust! [ATTACH=CONFIG]n1341015[/ATTACH]

Always a fun to pick up the wood! =)

[Drjay]

Hi,
From my boatbuilding days, I suggest you consider taping your paper pattern to the MDF and piercing it on the lines with a push pin. Then using a fairing batten connect the pin pricks with a pencil line on the MDF. You'll save your pattern and not risk things shifting around when you cut the MDF with your sable saw.

[brkitup]

I'm VERY interested to see how these turn out. Looks like a great design. It might be worth keeping the mid sealed instead of open-back, so you can participate in next year's InDIYana competition.