What materials should I be purchasing for my project?

[jbush2000]

Hey everybody, I'm new here, forgive me if this post isn't formatted correctly or even in the right place!

I just started working on designing a Bluetooth portable speaker enclosure for a summer project. I am really new with woodworking and I was wondering if anybody here could help me figure out what materials to buy, where to purchase etc. Currently I have the enclosure designed with 1"x1" actual dim. beams for the frame, and 1/8" thickness sheet material. I want the box to be somewhat durable (for going camping, tailgating etc.) but also I'd really like to keep the material budget under $100 (excluding the electronic components of course) I have attached a few rough renderings of what I have so far here.

I also would love some advice on the joint where the front and top frame members meet (I included a high contrast render so you can see the current plan for the joint). I have access to a pretty good range of machines at my college as well as at home, so feel free to come up with whatever solutions you can think of. If anyone would like CAD files I'd be happy to send them as STL files.

 

[Mike Davis]

My limited experience with speaker enclosures indicates 1/8 inch thick sheet material will be too thin to support and dampen the vibrations of the speakers. The box will buzz when bass notes are played. I would use 3/4 inch plywood or solid wood throughout.

 

[Rwe2156]

Looks like a well thought out design. I think it will work fine for a blue tooth speaker.

The joinery looks fine to me. You could make it simpler by doing an angled butt joint.

On the front, I would the angle either the face or top/bottom to match the plane in order to have a glue surface for the ply.

I would use 3/4 X 3/4 stock. Screw & glue them together.

Attach ply to frames with glue.

 

[Jeff]

Welcome to NCWW Mike.

I'm starting from scratch and pretty much clueless about Bluetooth technology. A few questions for you.
1. Do you have the Bluetooth speaker already and what are its dimensions? Manufacturer and pictures of that speaker for reference?
2. The box design shows 7 openings and what are those covered with?
3. The dimensions of your proposed box for the speaker would be helpful before choosing how to make it and what to use to make it.
4. Front angle? 60 degrees from vertical or thereabouts?

 

[redknife]

Mike is right, 1/8" will resonate. Since you talk about camping and tailgating, I think of plywood covered in laminate. If you want a wood look, you could use a 3/4 solid wood like pine and use an outdoor spar varnish.

 

[jbush2000]

Welcome to NCWW Mike.

I'm starting from scratch and pretty much clueless about Bluetooth technology. A few questions for you.
1. Do you have the Bluetooth speaker already and what are its dimensions? Manufacturer and pictures of that speaker for reference?
2. The box design shows 7 openings and what are those covered with?
3. The dimensions of your proposed box for the speaker would be helpful before choosing how to make it and what to use to make it.
4. Front angle? 60 degrees from vertical or thereabouts?

1. I am designing all of the electrical from scratch, so I will be purchasing a small Bluetooth module, a few car speakers, and actually designing the amplifier modules myself. I have a 3D printer at home and will be printing the electronics I/O box that will be attached to the back.
2. The 5 circular openings are where the speakers will be placed. I have a spreadsheet which will have my completed BoM, once I finish the design. The oval slots on top of the box are for carrying the box.
3. There are 3" diameter, 4" diameter, and one 6" diameter speakers in the enclosure in the corresponding holes. The box is 12"x 12"x 9".
4. Front angle is kinda weird, since I designed the box's top to fit 3 speakers, and the angle was a byproduct of the dimensions I really cared most about. CAD tells me front angle is 71.6 degrees from horizontal.

I linked my spreadsheet, which I will continue to add to once I flush out my design:
Bill of Material

 

[jbush2000]

Thanks for all the replies! Looks like general consensus is to use 3/4" ply correct? Something like this? Also for the 3/4" stock, would this work? I have a few friends at my college who are Electrical Engineers so I should be fine with the electrical components. I will upload a few more renderings of the project once I finish the redesign with 3/4" ply and add the I/O panel to the back.

 

[Graywolf]

You could use 1/2" materials for the case here. This would give you the dampening of resonance you need and reduce the weight over all

 

[Mike Davis]

Using 3/4 should eliminate the need for a frame.

 

[KenOfCary]

My initial suggestions would be 3/4" Plywood covered with veneer. Same as others have said.

As to sources, I'm not sure where to purchase veneer and such in NY. Don't use drywall screws, they're brittle, find better cabinet screws if you're using them at all.

 

[FlyingRon]

Back in the day we'd always use 3/4" construction grade plywood and cover it with indoor-outdoor carpet. If you were real high-fallootin' you'd use some auto carpet to match what you had in your car.

 

[jbush2000]

Thanks everyone! I'm going to go with the 3/4" plywood suggested here and use some 3/4" x 3/4" stock to reinforce the edges on the inside. I'll be sure to do an update post once I have the design finished and all of the electrical components sourced.

 

[FlyingRon]

You might find this page helpful in setting the dimensions: https://www.diyaudioandvideo.com/Tutorial/DesignBuildSpeakerBox/

 

[Gofor]

If you are an audio-phile, with excellent hearing, consider that better quality plywood will give you a truer sound. Baltic birch or equal quality will give you a clearer sound than cheaper ply that has voids in it. With my hearing, I probably couldn't tell the difference, but my wife and my ex-neighbor definitely could. He (the neighbor) had some high end custom speakers made from baltic birch and both he and the wife could definitely appreciate the difference between them and some with poorer quality enclosures.

 

[jbush2000]

If you are an audio-phile, with excellent hearing, consider that better quality plywood will give you a truer sound. Baltic birch or equal quality will give you a clearer sound than cheaper ply that has voids in it. With my hearing, I probably couldn't tell the difference, but my wife and my ex-neighbor definitely could. He (the neighbor) had some high end custom speakers made from baltic birch and both he and the wife could definitely appreciate the difference between them and some with poorer quality enclosures.

I will definitely keep that in mind. I think I should be able to get some nicer quality plywood from a family friend than what I was considering purchasing from Home Depot. Thankfully I finished designing the box, and just need to make my wiring diagram for it. (Hopefully I don't mess it up or this will be a very expensive one-time use fire starter!)

 

[nn4jw]

Given that this is portable Bluetooth I wouldn't get too hung up on theoretical audiophile considerations. From articles I've read on testing Bluetooth CODECs it still is not as good as good old wired devices. You also will be limited simply because of the physics of small speakers and the (battery?) power available to drive them. Finally, trying to keep the total cost below $100, including the electronics, pretty much limits performance towards the lower end of all possibilites. That's not enough budget for speakers alone if you are looking for audiophile quality.

All that said, it still should be a fun project and you'll learn a lot.

Edit: missed that the $100 was for the box only. Looks like the cost is climbing. Still won't be audiophile level though.

 

[Jeff]

material budget under $100 (excluding the electronic components of course)

For just building the box?

 

[bowman]

If you cannot locate baltic birch plywood, I hear good things about the Purebond plywood that Home Depot carries. It is made by Columbia Forest Products.

 

[jbush2000]

Yes, I have a spreadsheet here(link) which has the current list of components including electrical. I just wanted a fun project for the summer to keep me occupied. The system output will be 105W RMS driven by a custom battery cell (3s5p 18650 batteries to output 12V @ 15A with 13Ah capacity)

I just found the Purebond plywood, this stuff looks great! I am definitely going to be using this for the enclosure.

 

[JimD]

I have guilt a few speakers although not in a few years. 3/4 plywood will work well but MDF is often suggested for speakers due to it's lack of vibration. Most of us do not like to work with it due to the nasty dust but it is cheap.

An attractive way to make it would be solid wood corners biscuited to plywood or mdf. Splines would work too. I don't know what tools you have available or want to mess with. Be extra careful if you do biscuits on small pieces. Best to cut them to length after you cut the joint.