GM-416-8B MLTL Corner Cabinet

[VolvoHeretic]

Sri, I don't think that you need the rabbets or extra internal panel, it just makes it easier to assemble. I do think that you should add blocking at the new 90 deg. butt joints, and I would cut 2x material into 1.5"x1.5" triangles, they don't have to fit exactly at the mitered and doweled joints. I would ask GM what glue to use and how to reinforce the butt joints

I will try and finish up the plans this weekend and get a cut list for both 5x5 and 4x8. I am having difficulty coming up with a port layout that is both accessible, modifiable, and nice looking.

[srivenkat]

the important measurement you need for the depth is 20", half of the width and the distance from the back of the cabinet to the front most mitered angle. The first panel to the front baffle and perpendicular to it is variable and can be adjusted for Bv volume.




I do think that you should add blocking at the new 90 deg. butt joints, and I would cut 2x material into 1.5"x1.5" triangles, they don't have to fit exactly at the mitered and doweled joints. I would ask GM what glue to use and how to reinforce the butt joints

I will try and finish up the plans this weekend and get a cut list for both 5x5 and 4x8. I am having difficulty coming up with a port layout that is both accessible, modifiable, and nice looking.

Thank you VolvoHeretic.

For butt joints - For the front baffle (that's the only place we have butt joints if I am right), I thought of having a 1"X1" frame around (6.5" parallel boards will be extended to 7.5"). So, the front baffle will be screwed into this frame with neoprene gasket (to be removable). So, does this eliminate the butt joint block you are referring?
For Miter joints - I see in your diagram a triangle shaped (one end) vertical braces. Is this what you are referring to? If I go with dowel, would that simplify?

Thank you,
Sri

[VolvoHeretic]

Sri, a butt joint is anytime two pieces meet if they don't have some sort of step joint to locate them. So, the angled vertical board rapped around the back have a butt joint between themselves at the mitered angles, and top and bottom where they meet the top and bottom panels. The front baffle or the 1x's that the baffle will screw to will also be a butt joint. I think that they all need some sort of reinforcement, although GM has said that just a giant bead of PL400 will suffice. Altec just used a bunch of short triangular cleats spaced here and there to accomplish it.

If you build the front baffle removable, how are you going to attach it to the sub-frame and not have a bunch of screws showing? I thought that you could use entry door hinges or a long heavy duty piano hinge on one side and a double angle bracket on the other side that would bolt together, they would be visible on the sides of the cabinet, but the front baffle would look nice.

[srivenkat]

Sri, a butt joint is anytime two pieces meet if they don't have some sort of step joint to locate them. So, the angled vertical board rapped around the back have a butt joint between themselves at the mitered angles, and top and bottom where they meet the top and bottom panels. The front baffle or the 1x's that the baffle will screw to will also be a butt joint. I think that they all need some sort of reinforcement, although GM has said that just a giant bead of PL400 will suffice. Altec just used a bunch of short triangular cleats spaced here and there to accomplish it.

If you build the front baffle removable, how are you going to attach it to the sub-frame and not have a bunch of screws showing? I thought that you could use entry door hinges or a long heavy duty piano hinge on one side and a double angle bracket on the other side that would bolt together, they would be visible on the sides of the cabinet, but the front baffle would look nice.

VolvoHeretic,

Thanks for explaining, now I got it.

For the front baffle, hinge idea is great. Having a double angle bracket screwed to sides of the cabinet, would that be enough? Assuming that't the only part holds the front baffle.

-Sri

[srivenkat]

The woofer was set in a room mode peak, acceptable cab offset and the horn at the M19's spacing since he's using its XO, so no from a technical POV, but it's his speakers.........

Haven't gotten around to writing misc. final thoughts yet, but one is that the top plate ideally would be double thickness, whether one recessed inside or added to the top or a massive removable one such as marble, so something for him to factor in the decision.

GM

PS: great work BTW, do I dare ask how long it took?

GM,

Hope you find some time this week to write on the internal bracing, misc. final thoughts. This week, for my octagon built, I am scheduled to get
- BB Plys - 5 (5X5) boards or depending on VolvoHeretic's cut plan,
- 1-5/16" x 1-5/16" dowel or 2" X .75" ply - (totally 7) side wall braces,
- PL400
- neoprene gasket kit for NEMA 12

Any other input would be great. I will update once I have the boards.

Thank you,
Sri

[VolvoHeretic]

I was kind of busy this weekend, but I think that the front panel should be permanent and the rear most two mitered panels should be removable, I will try to work it out tomorrow.

Here are the preliminary cut lists; (6)-4x8 sheets or (7)-5x5 sheets. Is there a strong direction with Baltic birch (with the exterior grain in a 5x5 sheet)?

[srivenkat]

I was kind of busy this weekend, but I think that the front panel should be permanent and the rear most two mitered panels should be removable, I will try to work it out tomorrow.

Here are the preliminary cut lists; (6)-4x8 sheets or (7)-5x5 sheets. Is there a strong direction with Baltic birch (with the exterior grain in a 5x5 sheet)?

Thank you VolvoHeretic, very helpful.

I have only used BB so far, are there any other choices to consider?

I like to keep the front removable so I can use dual woofer sometime in the future. At the same time, I can use some screw caps or plugs to hide the front screws.

I found this neoprene - NEMA 4 (0.25" x 0.75"),
Hammond Manufacturing - 1481DJ10 - neoprene gasket kit for NEMA 12 enclosures - Allied Electronics

For veneering, what would be your recommendation. Last year, for a small project 3M self-adhesive paper backed veneer worked well compare to my failed attempt on using raw veneer. I found that wood backed self-adhesive veneer sheets are also available. Haven't looked into it yet.

Thanks a lot for your help.

-Sri

[VolvoHeretic]

Sri, if two woofers, are they aligned vertical or horizontal? If you want the front baffle removable, I think that you need two baffle panels, an inner panel that terminates at the horn mount bump-in and a finished panel that covers the entire speaker. I would be inclined to use 2x2's behind the first panel so that you have enough meat to sink its screws into.

For the gasket, I would think that you want a soft foam so that it compresses easily, and if need be, replace each time you open up the front panel, I can't tell from your link if your neoprene roll does that without feeling it.

Sorry, I know nothing about veneering, and have only helped apply it once, using contact adhesive and 1/4" dowels to position it over the substrate, and then carefully remove one at a time to lower the oversize veneer onto the panel.

This is all subject to GM's approval and his say is final.

[srivenkat]

Sri, if two woofers, are they aligned vertical or horizontal? If you want the front baffle removable, I think that you need two baffle panels, an inner panel that terminates at the horn mount bump-in and a finished panel that covers the entire speaker. I would be inclined to use 2x2's behind the first panel so that you have enough meat to sink its screws into.

For the gasket, I would think that you want a soft foam so that it compresses easily, and if need be, replace each time you open up the front panel, I can't tell from your link if your neoprene roll does that without feeling it.

Sorry, I know nothing about veneering, and have only helped apply it once, using contact adhesive and 1/4" dowels to position it over the substrate, and then carefully remove one at a time to lower the oversize veneer onto the panel.

This is all subject to GM's approval and his say is final.

VolvoHeretic,

Dual woofers are going to be horizontal and I agree I can have a complete new front panel for dual woofers when I am ready. For the dual woofers, I will be using bigger horn (511B) and the horn will be perched on top of the speaker cabinet with different XO.

So, for single woofer - according to your current cut plan. For dual woofer, I simply replace the entire front panel with a new panel which takes dual woofers and place the horn on top of the cabinet.

Of course, once GM approves we can finalize.

Thank you,
Sri

[srivenkat]

If you want the front baffle removable, I think that you need two baffle panels, an inner panel that terminates at the horn mount bump-in and a finished panel that covers the entire speaker. I would be inclined to use 2x2's behind the first panel so that you have enough meat to sink its screws into.

VolvoHeretic, If I understand this right, from your cut diagram board number 8 is the inner panel where I flush mount the driver. Or, you think I should have another board mounted (for almost 3/4 of the front panel height) terminating near the horn cavity? And the front panel is mounted on that along with the side frame?

For the glued miter joins, is it OK to use nail gun?

Thank you,
Sri