Make YOUR Own Portable Bluetooth Speaker From Scratch
Introduction: Make YOUR Own Portable Bluetooth Speaker From Scratch
In this instructable i will guide you through the steps of making a portable (bluetooth) speaker from the ground up.
It might sound like a hard project for the uninitiated, so my goal here is to help anybody who wants to try this by explaining things as simple as possible, without missing any important step. Let's begin!
Supplies
The most basic tools i consider necessary for making a speaker are a drill and a jigsaw, alongside with appropriate blades, drill bits (i also suggest a step drill bit) and measurement tools. Yes, you can get straight cuts with a jigsaw by using some straight wood pieces as side guides; obviously if you want to step up your equipment, a table saw and a router will be your best friends (which i still don't own though). You will also need a soldering iron and some tin to solder all the wires.
Other supplies you will need are: copper wire (red and black speaker wire is okay, black and red will help distinguishing positive and negative easily), screws (wood or metal screws depending on materials), wood glue (for wooden speakers), a glue gun and silicone (for attaching and sealing things), (optional) a heat gun (in case you want to flare and bend pvc tubes used as bass reflex ports), an on-off switch, a 2.1x5.5 (or preferred size) barrel jack (depends on the charging system), some kind of protective feet (i use rubber ones), a handle, some LEDs if you want.
Step 1: Your Budget
You should start from determining how much money you want to invest in the project, as staying in budget requires some balance (you can't spend 90% of the budget on speakers alone, as you won't have any for the rest).
If your budget is very tight, my recommendations is to reuse what you already have: old speakers or entire speaker boxes from micro-hifi systems, salvaged batteries (more on that in the battery section), leftover wood.
Step 2: The Materials, and Making the Box
You can choose basically anything as a material for a speaker box, but obviously not all materials are adequate, for various reasons.
My recommendation is to go with plywood: choose a variety that has a good compromise between stiffness and weight, because both are equally important in a portable design. You can either paint it with a primer, sand and then spray-paint to get the colour you want, or simply use wood paints to keep the wooden look.
Another widely used material is MDF, which is a good compromise all things considered. It must be treated with a sealant and not used as-is because moisture destroys it. As for the thickness, i'd say the same as above: not too thick because of weight, not too thin because the panels will vibrate. 996
I tend to use plywood between 10 and 20mm thick.
In case you find the material you chose to vibrate a bit, you can always reinforce it by doing internal braces.
So-so materials: metal (easy to work with but vibrates if thin, for ammo-box speakers i'd recommend building an internal wooden box), particle board (wouldn't buy it on purpose, but it can be used if you already have it), plastic (kinda like metal, plus all commercial offerings are plastic, why not make something different? ;) )
I attached some pics of painted plywood (made by my woodworker cousin), treated plywood and a metal box for reference.
Build your box the way you prefer, be sure to secure everything with glue and nails or screws.
Step 3: Speaker Types
This is a trivial part: what kind of speakers should I use? What if I don't know much about speaker building in general?
Let's start with car audio speakers (coaxials, 2 way, not subwoofers). These are very appealing to anybody who doesn't want to invest much time into making a crossover, calculating a box size etc. The problem with this is that you can't predict at all how the speaker will sound, because most of the times there's no information about them, aside from sensitivity, power and a (mostly useless) frequency response figure. My suggestion is: if you're on a budget and have some of these left over, use them. Do not try to make a ported box as most of the time it will sound bad! Make a reasonably sized closed box and they will play nicely. Just don't expect much bass out of them. For a rough estimate of how much volume you need, check this website (it's in german, but google translate can help :) )
To get the best results possible, you should buy hi-fi (non car audio) speaker drivers with documented specifications (known as Thiele-Small parameters), frequency response and impedance charts. 98