Introduction: Computer Speaker Conversion
Sick of having to cart a pair of computer speakers around if you want to hear some tunes away from you computer? Me too. In my room the only speakers I have are a pair of computer speakers which are stuck to my desk because of cords that loop around the back of the desk. If I wanted to use anything other than earphones away from my desk I wasn't easily able to because of the difficulty of moving around the computer speakers. This prompted me to get a pair of old computer speakers and put them inside a single box so that there were a minimal amount of cords and so they'd be easy to relocate when I needed to use them somewhere else. This instructable will guide you through this process of repurposing 2 computer speakers into a single unit. By the way this is my first Instructable so all comments and criticisms are greatly appreciated!
What you'll need:
- Pair of old computer speakers
- Soldering iron and solder
- Screwdriver
- Something to put the new speakers into
- Sidecutters
- Tinsnips (only if you want to get the old speakers apart without having to cut and resolder wires)
- Power drill, with drill bits and hole saws.
- Some way of decorating your speaker enclosure (not necessary, but something like an airbrush or normal paints are a good way to go).
- A way of fixing parts of your speakers to their enclosure. Screws, hot glue or Silastic are best.
Oh and a disclaimer, be careful. If your speakers have a transformer like mine you will be working very close to a lot of power. So whenever your doing anything to your speakers, make sure they are unplugged. I'm not responsible if you blow yourself up.
Step 1: Gather Parts
First you'll need to acquire a pair of old speakers plus amplifier and power source to put inside your new unit. Computer speakers are ideal since they have their own power source, amplifier, speakers and are a relatively simple design. If you can get some that have volume, bass, treble knobs, on/off switch and an LED, even better. Through whatever means necessary, remove the innards of the speakers and throw the rest out. If you want you can keep the meshy cover bit which can look decorative later on in the project. It may be necessary to cut a few of the wires and resolder them in order to get everything out, just make sure you remember which wires go where. I couldn't be bothered doing this so I made bit of a mess of the speaker shell and hacked them up with a pair of tin snips.
When your finished, you need to end up with 2 speakers, amplifier, power source (this one has a transformer and power plug instead of an adaptor) and an audio plug for your iPod/computer/whatever. Things like volume knob, LED, switch and meshy covers are also useful to have, although not necessary.
Step 2: Decide on an Enclosure
The third step is to decide on what to put the speakers in. This can be pretty much anything you want it to be. You could use a brick, shoe box, wooden chest or even a sock. Using a wooden box will give you the best sound, but I lack a suitable wooden box and I can't be stuffed making one so instead for mine I'm going to use a clear tupperware container. These can look really awesome if you paint something on the inside of the container and leave the outside clear.
Having completed this, I would actually recommend you make a wooden box to put your speakers in if you have some decent carpentry skillz. Not only will it make the speakers sound better but it will be a better fit because you'll be able to make it exactly the right size.
Now you'll need to put everything in to figure out where everything will go. Start marking some points on it where your going to need to drill holes for certain things. On the front you need to drill two big holes for each speaker, small ones for the volume knobs and a smaller hole for the LED. On the back you'll need to drill a hole for the power cord. If you have a switch you'll also need to mark a hole for that.
Step 3: Drill Out Holes
Drill out all the holes you just marked in the previous step. Use a hole saw for the two big ones (use a smaller drill to make a pilot hole first). If you don't have a hole saw you might be filing/sandpapering for a long time, so borrow a friends instead. Use normal drill bits to drill the other holes, make sure they are just a little bit bigger than what's going in them so it's a good fit.
Afterwards use a deburring tool or a piece of fine sandpaper to fix the rough edges the drill leaves.
This is also a good time to figure out how your going to attach the speakers, if they have little holes around the base like on mine, drill some extra small holes around your big ones to put some screws through.
Step 4: Enslosure Decoration
Before decorating our speaker enclosure it's a good idea to make sure everything fits. Put all the parts inside the box (loosely fasten them in) to make sure everything fits and see if there are any fatal flaws in your design. If there aren't, take it all out again and it's time to get painting.
There are a few ways to do this part. You could:
a) Mask up the outside and paint the inside so that the outside is all shiny.
b) Paint the outside any way you like.
c) Don't do anything at all. Leave it transparent so everyone can see your handiwork.
I went with a. To do this I put masking tape all round the edges and covered the rest in old fax paper. Then using a can of white spray paint I painted the inside of the container. When you remove the mask you'll probably find there will be a fair bit of overspray and dribbles that appear on the outside, so have some thinners handy to get rid of these. Painting it this way makes it appear white (or slightly blue in my case), but also gives a cool glossy finish because you can still see the plastic.
Step 5: Put It All Back Together
When you've got your box decorated the way you want it, start putting all the parts back in it. I put the amplifier in first because it's hard to get in with the speakers in the way. If you've put it at the top like I have, it's a good idea to use some type of glue (probably Silastic) to stop it moving around. Put the speakers, switch and LED in as well and solder anything that you had to cut to get them out of the old speakers.
The audio cable I was using had smaller wires inside the bigger wires, so if you have to cut the audio cable to get it through the hole, make sure you check to see if it was like mine and isn't actually 4 wires which you will need to solder back together.
When everything is connected, plug it in and make sure it works. If it works, screw/fix any remaining parts into the box and start to add some finishing touches. If your speakers have the transformer like mine does you might have to make up some sort of frame for it on the bottom of the container to stop it moving. I just used to Silastic to glue it to the side.
Step 6: Finshing Touches
Finally it's time to add the finishing touches. Grab your sharpie and make little symbols around the volume/bass/treble knobs. You could add a little power or on/off symbols above the LED and switch as well. If you have something worthy of the job, you can also make up little meshy covers for each of the speakers, probably using the screws that are already there to hold the mesh in place. I couldn't find anything decent to make some out of so I just left them as they are.
Then once you put the lid on it, it's pretty much done and the only thing left to do is rock out! Hope you enjoyed this Instructable! :)
28 Comments
12 years ago on Introduction
Ok so I've built this instructable. Tested my speakers after disassembling the original casing. Did some offboard rewiring of my pots/volume, bass, and treble. Built a clock and a lamp. And retro fit it all into an old am radio. Basically Ive put alot of work into this. Now I placed my amp assembly and speakers in and BOOM no sound from one speaker!? I've checked my connection and even tried other speakers? All end up the same, very very little sound. Anyone have any other suggestions?? Its the speaker directly connected to the pcb if that helps? Really wanna get this working
14 years ago on Introduction
can we use electric tape
Reply 12 years ago on Introduction
NO!! just kidding I dont see why not...
14 years ago on Introduction
What's the best way to hook up some batteries to make it a boom box? I need it to be portable for my skating needs. It will probably have a switch to switch the power input from AC to DC. Thanks.
14 years ago on Introduction
Since the cabinet is made of thin plastic (in this case), there will be a wide range of frequency ranges comming out 180 degrees out of phase anyway. If you're going to concern yourself with a tuned port, insulate the inside of the tub with some acceptable substance (fiberglass or similar).
16 years ago on Introduction
If you're going to take speakers out of a well-designed enclosure and put them in a new enclosure, it's a good idea to understand a couple of things about enclosure design and copy those aspects of the original enclosure. Most speaker enclosures are bass reflex enclosures tuned to the characteristics of the driver. In particular, the VOLUME of the box is important---your box should be the same size, even if it's a different shape. (Shape doesn't matter as much as the volume of the box.) It should also have a hole in the front of roughly a certain size. The box and the hole act as a filter, by delaying the pressure wave coming off the back of the speaker and redirecting it to the front. The pressure from the back of the speaker is the reverse of the pressure from the front, and there's a slight delay in that sound path, because the pressure has to travel a little further to get to the listener. That delay is important. If the enclosure is designed right, the sound coming out of the hole will be in phase with frequencies you want to reinforce, and out of phase with frequencies you want to partly cancel out. In particular, most drivers have a peak in the bass response, and steep fall-off at frequencies below that. You engineer the delay to partly cancel out that peak (by being 180 degrees out of phase) and reinforce frequencies about a half an octave above and below that. That smooths out the bass response and extends it about a half an octave lower. (IIRC. It's been a long time.) You don't really need to understand this to replace a speaker enclosure with one that sounds pretty good, too. You just have to know that the volume of the enclosure and the size of the hole matter, and copy them. The shape of the enclosure doesn't usually matter nearly as much, so you have a lot of freedom to substitute more convenient or cool-looking enclosures. Just make sure your enclosure has the same volume and a similar-sized hole in it. If you choose the wrong size of box, you may do a lot of harm to the sound. It may reinforce frequencies that are already too loud, and cancel out frequencies that are already too quiet. (If the hole is too small, it won't do much good in terms of shaping the bass response, and will "whistle"---air pumping through the little hole will generate extraneous noise at higher frequencies.)
Reply 15 years ago on Introduction
Only thing is drcrash, the mathematics to tune a speaker enclosure to a specific frequency are very complicated and without the proper datasheet with the thiele-small parameters on, it is almost impossible to calculate how long the port should be and how big. Basically what I am saying is that putting a port in a box that hasn't been calculated properly could make it sound worse rather than better. The best way for speakers such as these is to put them in a simple sealed enclosure that doesn't need any calculations for it to give a reasonably flat frequency response. After all, it is meant to be a simple project that is portable.
Reply 16 years ago on Introduction
Computer speakers of the caliber used for this project are likely generic drivers placed in generic plastic enclosures by the original manufacturer anyway. While most of your observations are valid, it is doubtful that the manufacturer paid as much attention to detail. Problems of phase should be minimal and a moot point when drivers are in such close proximity (point source). Box volume without a port needs to go up and usually produces a more accurate, though less efficient and less dynamic, speaker. Were he to port it, there would have to be an appropriate tuning frequency of said port that corresponds to roughly that of the lowest frequency the driver is able to reproduce. That means a tube of a particular width and length. Done correctly, this would improve the overall sound quality of the speaker. At the end of the day he would, however, still have $2 drivers stuck inside of a Tupperware container and driven by a flea powered amplifier. IMHO he should be happy with his wicked cool looking and convenient little boom-box without regard to achieving audiophile nirvana (which is a myth anyway).
Reply 16 years ago on Introduction
Although I do appreciate all this input from everyone, your correct in assuming that at the end of day, this is just an instructable about how to make a cool, small and practical boom box. Maybe later in life I'll chase after this audiophile nirvana, but at the moment such a dream is far beyond my grasp.
Reply 16 years ago on Introduction
I'm not really talking about audiophile Nirvana. Most of my speakers come from the Goodwill outlet store, for a few bucks. Some computer speakers really are better than the ultra-cheap, ultra-low-powered computer speakers, and cost less there. (I have a 200-watt THX-certified Klipsch sub-sat set, and there's a lot of stuff well below that but still above the cheapest generic drivers in generic boxes.) To me, it's worth starting with decent speakers if you're going to put the effort into a case mod. Audio quality isn't an all-or-nothing proposition. But then, maybe that's just me. If people just want an easy hack for the cheapest speakers, that's fine by me, too. Go for it. Nice instructible.
Reply 16 years ago on Introduction
dude, although you are right about what you are saying, box volume, airflow etc... im sure people who are making this arent going to use this is a hi-fi needed sound enviroment, meaning they dont care much about their audio quality for their ipod/ mp3 player. Also, since when were COMPUTER SPEAKERS high quality. I have made something similar and you can barely hear the audio quality difference, no matter how bad you make the new box, either completly closed up with no airflow holes or no sides to the boxes. it doesnt make that much of a differnece.
Reply 16 years ago on Introduction
You failed to mention the two speakers in one enclosure. Frequencies canceling out because they will be out of phase from one speaker to the other. Of course with such a flexible enclosure this is all moot anyway.
Reply 16 years ago on Introduction
You could always just make sure to wire them in phase. Thaat seems to make the most sense to me.
Reply 16 years ago on Introduction
It's not the electrical phase that is the problem, it's the acoustical phase that would cause a problem.
Reply 16 years ago on Introduction
if the electrical phase is in sync, why wouldn't the acoustic phase be? That may be a dumb question, but I am somewhat new to audio electronics.
Reply 16 years ago on Introduction
If it's stereo or anything that is 2 separate channels a signal might be out of phase.
Reply 16 years ago on Introduction
cant you just put something in the middle of the two speakers so the preassure waves is blocked from each other...
Reply 16 years ago on Introduction
Wow thanks for the humungous tip! I really appreciate and will be taking it into account for next time. I was aware that the old computer speakers were bass reflex and that ! should try to replicate it but I couldn't be bothered and wasn't sure how much difference it would make. Since this is only an experiment I'll be doing a more careful job next time and will recreate a similar size enclosure to the original out of wood so i can get the measurements right. Again thanks!
15 years ago on Introduction
this sounds awesome!(pun un-intended lol) im making this for my art teacher because she spent the whole period complaining because the school computer wouldnt play the songs on her ipod lol
15 years ago on Step 1
I'm just wandering coz I like a electronic noob is the transformer and the amp are safe to touch when it has been un plugged