Ultra Portable Ipod Speakers

Intro: Ultra Portable Ipod Speakers

This is how to build a tiny pair of speakers that simply clips onto your ipod/mp3 player, and are surprisingly loud.
Word of caution: If I were you, i would not use these with mp3 players that use hard disk drives (as opposed to flash memory, like many newer ones) because there is a chance that the magnets in the speakers could mess up the data on the disk, and brick your player.

So i built this, not knowing how well it would work, and when I finished, I realized that I should have taken photos so I could make an instructable about it. So I have whipped out my trusty tablet, and recreated all the steps by drawing them out in painter 6. If anything is confusing, please tell me so i can clarify.

STEP 1: Materials

2 smalll rectangular speakers. I got mine from an old and broken dell latitude cp that was about 10 years old

8mm male audio jack

Sheet aluminum. I just used aluminum flashing, which is extremely thin, and can be cut with scissors

Aluminum tape

STEP 2: Wiring

Cut the audio cable about two inches from the end, and strip off the plastic around the bundle of wires. There will be 3 wires inside: a ground wire, a wire to the left speaker, and a wire to the right speaker. The ground wire probably will not be coated in plastic, or it will be black. Strip the plastic off the wires to the left and right speaker, and twist the two wires together. This will make the signal to the speakers only one channel, and it will make it a little bit louder. Connect one wire from each speaker to the joined signal wire, and the other wire on each speaker to the ground wire on the jack. Once you have done this, go ahead and plug it into your music player to see if it works.

STEP 3: Laying It All Out

Cut a strip of aluminum a little bit wider than the speakers are tall, and about three times as wide as the two speakers and the jack combined. Trace around the assembly, so you will know where to drill holes.

STEP 4: Drilling and Gluing

Once you have marked around the speakers, drill 1/8 inch holes in the part of the aluminum where the speakers are. I just made straight rows and columns, but you can do any pattern you like. Once you have drilled the holes, roll the sheet of metal with a rolling pin, or something similar to flatten barbs from the drilling. Put the speaker assembly back onto the aluminum, and hot glue it in place. Try not to put glue on the fronts or backs of the speakers, as it will dampen the sound.

STEP 5: Finishing Up

Fold the aluminum around the speakers, so they are fully enclosed. On the back, where the metal overlaps, cut a small piece of aluminum tape, and tape the two together. If you want, you can cut an aluminum piece the same shape as the bottom, and glue it in, so the speakers don't show.

STEP 6: Version 2.0

I was unhappy with the way it looked so I redid the outside.  While I was at it, I rewired the inside so that I do not mix channels, as some readers were concerned with that.  Also, I made a video of it playing.


This project, along with other, can be viewed on my blog, which can be found here:

http://build-its.blogspot.com/

Comments

[wobbler]

There seems to be a lot of misinformation going on here about the ability of these to blow up your mp3 player. i will use the word speaker and headphone to be interchangeable with regards to the electronic equivalence of both.

Firstly, there is a difference between speaker resistance and speaker impedance. Resistance is the dc value, impedance is a the AC value. Impedance is much more complex than the dc resistance and changes with frequency depending on the speaker. There is no simple single value for impedance, but it is usually specified as "not dropping below" for speaker/amp combinations.

Speaker leads effectively have a resistance and impedance of zero. It is within the speaker (and crossover if used) that the majority of impedance and resistance is realised.

As we are now talking about headphones/speakers I will now refer to impedance instead of writing impedance/resistance every time.

Can these blow up an mp3 player by having too low a resistance? The answer is probably no. The reason is that an amplifier is designed to work into a particular load. Why is the load important? The answer is that for efficient power transmission to the speaker, the amp will have a matching internal impedance to the speaker. So for an mp3 player designed for 32ohm speakers (e.g. ipods) then the amp will have a matching internal impedance of 32ohms. So what happens if you put in lower valuespeakers? Theoretically the power will rise, but it won't rise by as much as the simple volts amps resistance calculation of the speaker will imply as done by many above. The reason is, with a 32ohm speaker design, the total resistance of the driving amp combo will be 32ohms internal + 32ohms external speaker or 64ohms. With 8ohms speakers, it will still be 32ohms internal and 8ohms external or effectively 40ohms. Even if the outputs are shorted out, it will still only be capable of delivering twice the power that it will deliver through 32ohm headphones, which will not be sufficient to fry any internal transistors. In fact, the Apple headphones themselves actually go down to 23ohms according to Apple and will possible dip even lower in the real world.

What will happen is that as the resistance of the headphones is dropped, the power will be delivered less efficiently so you would need to turn up the volume more, all other things, such as efficiency, being equal.

Also, would a company really want to send out a design which is prone to failure when speakers of 8ohms are attached? There are also some headphones with such a low impedance. The answer is no or they would be risking a large return rate due to people frying them. It wouldn't make either good design or business sense.

The other issue is the comments about putting resistors in the leads or diodes. Headphones shouldn't have a resistor in the leads. If they do, it is a cheap and nasty solution to impedance matching. The reason is that a resistor is pretty much a flat impedance across audio frequencies. This means that it will actually cause any fluctuations in impedance at the headphone to be amplified and emphasise any impedance frequency issues making the headphone response less smooth. So why do hifi speakers use resistances in the crossover? The answer is that they are used to balance out the different sensitivities of the different speakers used and are part of a more complex circuit, not simply acting on their own. As to putting diodes in the signal path or leads, this isn't a useful suggestion. It will firstly only allow one half of the signal through. Secondly, real diodes have a turn on voltage so below that no signal will come through and it will then be distorted when it does.

So can you blow up an amp by putting in too low an impedance speaker or shorting it out? The answer is yes, but that is for amplifiers which have much more current providing ability and higher driving voltages and lower internal impedances than standalone headphone amps or mp3 player amps.

http://www.audioholics.com/loudspeaker-design/loud...

http://www.apple.com/ipod/in-ear-headphones/

[Finley Ferguson]

The above technique of making this speaker is really defined good . Specialy the pictures are added int it are helpful and easy to understand . So much thank you for it

[Finley Ferguson]

http://www.braaper.com/

[cortes96]

That's cool, what if you got one of those small portable iPod chargers and put that behind the speakers and make the jack long enough that it will fit and you will be able to charge at the same time

[iApple guy]

Use a lm386 amp

[dhananjay89]

i also made speaker of same size but they hav built in amplifier and battery .you cant get a loud sound by simply connecting to the output which is meant for earphones

[tinmankingkinney]

just a tiny complaint about the wiring* dual channel audio sounds better....and if you are reading this instructable you probably should have an idea of what you are doing already, but if you don't then here:

[ben_k]

I rewired it in the updated version. However, since the speakers are right next to each other, there is no benefit to having stereo sound anyway.

[didgitalpunk]

i guess ading two diodes on each wire could solve that problem.

[its2l8men]

you could destroy your mp3 players with dis

[its2l8men]

you ruined the aluminum!

[arduinoe]

Ive sent you a friend request for msn on that hot mail :). Also sent you an email in case you dont use msn much

[arduinoe]

with no amplifier , your gona be toasting your poor ipod , those little speakers are very demanding on the power front (about 60 - 100 ma !!!!!) and designed to be used with an albeit small amplifier , your ipod is gona be a deadpod soon :( . the LM386 chip is almost a complete stereo amp on a chip and should be great for this project. plz dont kill your ipod , its a touch to.

[ben_k]

I'm pretty sure the speakers will only draw as much power as is available to them. My friend has some huge headphones that play almost as loud as this, and it doesn't fry his iPod. And I've been using things like this on my iPod for ages, and it's still going strong.

[arduinoe]

im no talking about bangin tunes power , im talking about the ma being pulled by the speakers.

(amps ( or ma) x V = watts)

so lets say your ipod battery is 3.7 V (it would be as it is a single cell lipo battery)
100ma = 0.1 A

3.7 x 0.1 = 0.37

lets say 0.4 W
a set of ear phones are about 0.05 W

thats 8 times the power of a set of earphones.

As for speakers only pulling as much power as is available , its sorta the other way round , there is no limiting on the ipod. it would be nion impossible to implement limiting , without the ipod knowing what sound output device it was connected to , earphones only pull 0.05 W , so no limiting is needed , headphones however , given half a chance will pull into the amps , thats why if you crack open a set of headphones you will find a resistor somewhere in the circuit , they are normally buried somewhere in the jack.

if you need any help pm me : )

[ben_k]

And how does that result in a fried iPod...? And most headphones don't have a resistor in them. Take one apart for yourself and see.

[arduinoe]

It results in a fried ipod because the transistors amplifying the sound signal are having way more power pulled through them than they are designed for , this results in thermal run away and eventually a fried ipod sound card. As for the hedphones , all headphones of a moderate size will have a resistor (and possibly a choke) somewhere in the circuit. referring to my earlier post . lets say your ipod can safely output 0.05 W A pair of headphones only needs 0.05 W and will work happily on 0.05W . But if it is not limited , it will pull as much power as it possibly can leading to dead transistors. I would recommend putting a 20 O resistorsomewhere in the circit , or adding a small amp . It will be a lot louder with the amp.

[xana]

i am a dj and a circuitmonky my studio monitors do not have a resister in them theas are a good pair that cost me $300 yet they do not have a resister. so to be a good pair i gess they do not need a resister.  on another note go open sorce ipods are overrated.

[riverreaper]

monitors are for viewing not lissening so even if yours did why would it matter? the sound travles a difert path an i wonder about theses who say mine dont have a resister as to weather or not they realy know what one looks like ,  oh darn i wasnt going to go on an atack mod guess im no better or worse for the wear , ok im back at figuaring out how to get the cats scatch pad hooked into my TOTAL CONTROL so he/she ca dj with me been cool all peace out

[xana]

studio monitors are headphones not computer monitors aw well.