Introduction: Portable Boombox / Cooler

This an instructable of a project I just finished in preparation for summer weather. I have taken inspiration from the "Coolest Cooler" and other cooler / bluetooth combos on the market. For my taste, I decided to aim for higher overall sound quality for my rolling party instead of other thrills and frills.

I am posting all my design prints on this instructable to help anyone who wants to try and make it. Feel free to send me feedback or ideas on advancing the design.

Step 1: Materials

To recreate this project you will need the following....

Woodworking:

  • .75" thick wood panels. I use the pine edge glued panels from Lowes, but if your crafty enough you can make your own. (It is important for them to have uniform thickness and try to avoid plywood or MDF if you plan on using it outside)
  • Router with .75" dia router bit
  • Circular saw
  • Jig Saw
  • Sander
  • Clamps
  • Stain
  • Pencil, ruler, etc

Electronics:

  • Turnigy 2200mAh 3S 20C Lipo Pack
  • Neewer® B3 AC 100-240V 2S-3S Cells 7.4V 11.1V Lipo Battery Balancer Charger
  • Lepai LP-2020A+
  • bluetooth reciever
  • Speakers (I took apart an old unused bookshelf speaker for its drivers and crossover)

Accessories:

  • Igloo earth 24 cooler
  • Dolly wheels 8" dia
  • Luggage handle

Step 2: The Design

My design went through a few iterations during the build and will probably never be done. But here are the drawings of what I have landed on for now.

Just thinking out loud.....

I am not a particularly skilled wood worker, so I like to try and hide my mistakes in the design joints. Due to a lack of equipment and skill any cut I make tends to be neither square or dimension-ally accurate. So the "Dado joint" is my favorite way to hide my errors. If I have any miss-measurements or errant cuts there is not a blatantly obvious gap in the joint, but instead the gap is hidden from view inside the groove.

With that being said, as you can see my design contains almost all "Dado Joints", and (bonus) this tends to lead to a stronger structure as well.

Other design thoughts....

As I stated earlier, one of my main goals was sound quality. The design has around a .6in^3 enclosure for the speakers, and the wooden structure will hopefully help aid to quality.

Instead of permanently attaching the cooler I went for a modular design. This way the cooler can be removed and replaced with other things like a tool box, tackle box, etc.

Step 3: Construction Begins With the Router

I do not have a router table, so to achieve a usable routed grove I clamp a straight piece of wood down for the router to follow.

  1. First you must measure where you want the groove and find the center of the groove.
  2. My router is 6" in diameter so from the Centerline of the groove I add 3" to find the location of my straight edge.
  3. I set the depth I want in the router bit and make the cut holding the router against the straight edge as I go down the path.

(I also do not have a plunge router so I started some grooves with a .75" drill bit for my router to start in)

Step 4: Assembly

Hopefully all your routed grooves are clean and match the prints. If you are confidant with your build now would be a good time to glue and clamp everything together. But since I still want to play with a few design changes I decided to temporarily screw it together. (remember if you do this you will have to later try and fill those unsightly pilot holes)

Step 5: Failed Design

Just for fun I would like to show one of my failed designs.

I originally had the table top wrap around the cooler so it cool also be used as handles. I think it looks pretty good too, but it wasn't long until it broke. A dead spot in the wood seems to be the culprit this time, but I decided to nix it anyways. I figure the stronger the better when the day drinking / tailgating version of myself gets a hold of this.

Step 6: Electronics

The electronics portion of this project was more of a plug and play situation. There are several good portable bluetooth speaker instructables that can do electrical engineering way more justice than I can.

The Lepai amp and turnigy battery match up very well. I just simply spliced the outgoing power lines from the battery with the DC power in cord. The DC wall-wart that came with the lepai was 12v 2a and that matches the batteries power output. My only concern from reading around online is the Li-Po batteries are known to be a fire hazard. I plan to come up with a more permanent housing for the battery in the future.

As for the bluetooth. I plan to follow something similar to this:

https://www.instructables.com/id/Portable-Bluetooth-Speaker-Boombox/

but my bluetooth receiver seems to be lost in the mail. Until then a headphone jack has been working just fine for me.

Step 7: Final Touches

I ran a "round over" router bit on all the outside edges to clean it up. And I hit any raised edges with the sander before staining it.

I had some old dolly wheels to use and I tapped the ends of a 1" dia steel bar for an axle.

I bought a 170lb folding cart dolly off ebay for the retractable handle. I figured go for something more sturdy, but really anything would work. Try checking goodwill for old luggage. If not here is the ebay link:

ebay 170lb folding dolly

Step 8: Further Redesign

As I said the re-designs will never stop. I am currently interested in adding some pocket shelves for coozies. Or somehow have the handle be dual use as a seat back.

I would love to hear if anybody has any further designs or feedback.

Comments

author
philip.williams.7505 (author)2015-03-29

This is an awesome project! The all-in-one party station for any occasion. I like it!

author
lrohde (author)2015-02-18

Very cool your portable boombox!!!

author
b5125125 (author)2015-02-07

how long does it last on one battery

author
BryantM (author)b51251252015-02-08

I haven't ran the battery dead yet to be honest. I've played it an hour or 2 at a time (totaling maybe 6 hours without recharge). But the weather hasn't been good enough for a full days run. Maybe I'll run it one day and time it.

author
lutkeveld (author)BryantM2015-02-15

The Lepai uses around 1-2W at medium, 4-5W at maximum volume. Battery capacity is amperehour times voltage. Playtime is capacity divided by usage. You do the math :)

Remember to turn the system off when the battery voltage hits ~9V to prevent damage

author
willi1131 (author)2015-02-10

I am building something similar myself, just use a car bettery. 600Wh are way better than 24 with a lipo. many hours more music;)

author
erick.truter (author)2015-02-10

I am interested in the battery solution. But would a 2200mah only give you 1 hour? From my RC Helicopter experience these batteries do not like to run flat. They will expand like a balloon and be ruined. Would be nice to have a battery cutoff when the cells drop below 3.6-3.7v to save the battery.

author
wb7ptr (author)2015-02-09

I like this. Think I'm going to try and create a version which merges ham radio gear, a cooler and a boombox, or perhaps a guitar amp and cooler for the street musicians. I can think of endless variations and mutations of this project. I'll post if I build something like that. Your project is great :)

author
wb7ptr (author)2015-02-09

I like this. Think I'm going to try and create a version which merges ham radio gear, a cooler and a boombox, or perhaps a guitar amp and cooler for the street musicians. I can think of endless variations and mutations of this project. I'll post if I build something like that. Your project is great :)

author
onemoroni1 (author)2015-02-08

Of all the boom box instructables this ranks as one of the better, nicer builds for it's appearance and utility. You have done good reasurch and resourcing to accomplish the project.

author
danzo321 (author)2015-02-08

You show a three-way speaker array but say you got a two-way crossover.. what's up with that? The air chamber behind a woofer acts as a spring, that's why in a closed (infinite baffle) design the volume of that box should be built exactly as specified. They measure the forward-back travel of the cone, times the cone diameter, to get a number called "Q".. used in the formulas.

author
BryantM (author)danzo3212015-02-08

Kind of confusing I agree... My photos are of my first attempt when I took apart an old Yamaha bookshelf speaker and used the 3-way crossover and drivers from it. But I think those drivers were damaged so I ordered a new 2-way set. (I just received them in the mail so I will update the photos soon.)

I don't know much about enclosure design or driver selection so I am open to any comments. Do you think adding a bass port will help?

author
danzo321 (author)BryantM2015-02-08

If you want a speaker that will "change your life" (ha) you need 10" + and real power. And bass reflex (ported speaker) design doesn't really get going til you are in the Big Boy division. Most bass reflex enclosures use 15" woofers.

author
Kogalskaben (author)2015-02-05

nice build and idea.:-)
But instead of the Lepai amp i would suggest a maxamp or some other ta2020 amp, without case, alot better sounding then the lepai and can be integrated into it, and add a volume knop into the wood parts.:-)

author
BryantM (author)Kogalskaben2015-02-08

Hey cool I'll have to research that. That would look a lot cooler with the knobs built into the wood panel.

author
danzo321 (author)2015-02-08

Great job. If you get outdoor grade plywood, that will be plenty good enough.

author
Rajat Cool (author)2015-02-06

Very cool but you should have uploaded a video.

author
tomatoskins (author)2015-02-05

This turned out great! Any way that we can get a video so we know how it sounds?

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