Instructables
Picture of Portable speaker in a CD case!!
Have you ever thought of making your own portable speaker in a CD case? Here is how you do it.
 
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Step 1: Components required

- 8W speaker with 4 ohms impedance (Make sure the speaker's impedance must match your amp's specification or you would damage your amp!!)

- CD case ( Use the one with a zip would be good)

- 18W Amplifier module (I used the Kemo #M033, you can use other amplifiers as long as the Watts are not 2.5 times larger than your speaker's power level)

- Rocker switch

- 3.5mm stereo adapter

- Battery snap and a 9V battery

- Solder iron and some solder

- Glue gun

- Cutting knife

- Drill

Note that:
If you choose an amp that is supplying too much power to your speakers, then its clear that there is a chance that you will damage them. It may cause the voice coil to overheat, or the speaker could move back and forth too much (known as exceeding its Xmax).

However if you have a smaller amplifier you may have to run it all the way up full to provide enough power to your speakers. When running at full blast, there will be lots of stress on the components of the amps and it can introduce a significant amount of distortion into your signal, which is often called 'clipping'.

As well as sounding very bad, trying to reproduce a clipping signal can potentially do far more damage to your speakers that a little too much power.

Therefore the unwritten rule is that you should have an amplifier that is capable of 1.5 to 2 times the power rating of your speaker system, and only turn it up part way. The extra power available is called the headroom, and means that your amplifier should never been running at full tilt and therefore producing a distorted, or clipped, signal.
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Kodak883 years ago
I would recommend not putting the iPod inside the case, as the magnets from the speakers could mess with your iPod's memory! Just a thought.
T0C Kodak883 years ago
Nah it won't... these days electronics almost aren't effected by magnets (excluding CRT monitors), here you don't have a tape to blank when you run a magnet by it :D. it's all just thousands and thousands of transistors (in chips of course well by that i mean , let's say you have a cpu in one of the older versions i remember there are about 73 mil. transistors and that cpu is from 2001 i think so....)
zgybrwn T0C5 months ago

you don't have to explainit when you say something simple like you are the smartest one every.

T0C zgybrwn5 months ago

I didn't quite get that, would you mind re-writing it a bit better.

Besides, the answer you replied to is 2 years old!

Kodak88 T0C5 months ago
I was actually responding to the other guy (zgybrwn) who responded to you. He basically called you a know it all for explaining your reasoning behind your comment to my original one. Also, not to nitpick, but my comment was worded properly in context, so I have no idea how to rewrite it for you.
It doesn't matter anyway, the guy was just being rude.
T0C Kodak885 months ago

Yeah, I got the part about me being a know it all, his comment just seemed unfinished the way it ended but I guess he/she doesn't speak English that well (not that I do).

The re-writing part was addressed to zgybrwn, I had no trouble comprehending you comment..

Also looking at the time our comments were send we must have sent them at the same time, hence the confusion about who replied to who.

Kodak88 zgybrwn5 months ago
Did you read the "we have a 'be nice' comment policy" disclaimer below your comment? Dude was just explaining his/her thought process, on a website *designed* to share information. So if you don't have anything nice to say,gtfo.
bigjeff5 T0C2 years ago
Just wanted to give you some updated numbers:

The Tegra 2 (used in many smartphones but is being supplanted by the Tegra 3) has 260 million transistors.

Most modern desktop CPU's have between 250 million and 1.2 billion transistors, while server CPU's can have up to 2.5 billion transistors.

Modern desktop GPU's can have up to 4 billion transistors.

Most people will never encounter an FPGA (a sort of reconfigurable CPU), but they can have just shy of 7 billion transistors.

A gigabyte of DRAM (the kind of ram in smartphones and PC's) has about 8 billion transistors.

A gigabyte of Flash memory has either 8 billion (SLC) or 4 billion (MLC) transistors.

It would take a horribly powerful magnet to mess with any of it, since they all off specific electrical signals at certain voltages which are incredibly difficult to generate by accident with a magnet. As you pointed out the magnets were a concern for certain magnetic storage technologies. Even then, while a floppy disk could be damaged by an errant magnet in the pocket, even modern magnetic hard drives require much more powerful magnets to destroy the data without physically touching the platters inside (hard drives actually have quite powerful magnets sitting right next to the platters which don't affect the data at all).

Simply put, it's not likely you'll be able to get your hands on a magnet powerful enough to hurt your smartphone, and you most certainly won't be able to get that magnet to fit in your pocket.
T0C bigjeff52 years ago
Yeah, the cpu i mentioned wasn't from 2001 but from 1991 or so lol.
About the hard drives, i've seen the magnets inside and they're really powerful but as you said they can't erase the data, to erase the data (and probably completely destroy it) it would take a magnet about as powerful as an MRI or something bigger.

There's always a way :) and most of the time it's fun as hell!
hajk2 years ago
Hello!

I wonder if i can make it work with a 80 Watt speaker?
hows the sound? assuming that your using a subwoofer the bass should be outstanding
rohaanwadia2 years ago
so if i am using 2 8watt 4ohm speakers then is a 30watt amp appropriate??
jholley13 years ago
i bought one like this but allready built
krayola4 years ago
panalo to dre! hehe gumawa din ako nung little gem and MKII na guitar ampli. this site is the best.. the ideas are the best..
ASCAS4 years ago
I would try to link you on a site where to buy a 4 inch 20W speaker 4 ohms. I already have one and here in our country (philippines) it only cost $2 in php-dollar converstion. The speakers give a high quality BASS, MID RANGE and TREBLE. Its worth every penny. I could even be sold for $100 because of it's quality.
dhvinay4 years ago
pls suggest me where to get the amp from...
any preferable online websites ?
LkArio5 years ago
That's nice, but 18W is too much for such a small speaker.
musick_085 years ago
how would you do this without the amp. ( I'm new to electronics.)
In my opinion: You can't feed speaker without amp. You could burn your device output.
ok thanks. i thought it would, but i wasnt sure.
ok i'm worrying bout something, surely if you are running the power from the 9volt through the stereo jack, it is being pumped into your ipod of mp3 player, doesnt that do damage to it? also, are the stereo jack, battery and switch in series on the input circuit?
of corse you could put a diode from th 9V
Jonas4125 years ago
You could just make a simple aplifing curciut with transistors ans a potentiometer
raikut5 years ago
But what if we don't get this type of amp in our country
it would be cool if there was a pot for a higher volume control other than what is on your I-Pod.
seraph6 years ago
would a 15w speaker work with the 18w amp? and also, where can I buy most of these components... do you think radio shack would have it?
bigern71 seraph5 years ago
check a hobby store also
it might though, radio shack has everything.
fatrickuk (author)  seraph6 years ago
yeah, it would work. I am not sure about radio shack coz I don't live in the US. Hopefully some people would be able to help you to find the components.
that's sweet...but what are you doing with a cd case if you have an Ipod?
ok, scratch that...I din't realize how big the speaker magnet was...but still sweet
armynavy175 years ago
Ok so I'm thinking about doing something like this but with two speakers. They are both 1W 4ohm speakers. I want them to still be stereo so do I need two amps? Should I use a 2W amp(s) or something else?
Or if I didn't have it stereo and I ran them both off of one amp could i use a 3.5W amp?
comodore5 years ago
Can you make this operate 2 speakers like 2 head phones? Great project man! I love it! PS: comment number 101! hehe
djshalford5 years ago
its been a while since i studied but if the two left and right signals are being combined pre-amp it shouldnt need the resistors? (or is that to stop any distortion?) and i have a double cd case and im thinking of doing a double speaker version since this design only puts one signal through amp (if it works) then should be able to double up on everything except stereo jack... i.e using the two mono signal amps two speakers two switches connected as seperate circuits with negative of batteries to negative inputs of individual amps and those connections connected together at the ground terminal of the stereo jack and two different signals (left and right) going to seperate amps and concurrently speakers. Please comment on idea usefull feedback might jog my memory to whats being missed in the circuit (besides a fuse) ... thank u
wow, i wanna make one...A few questions though. Where can I Obtain these supplies, and how much would all this cost to make?
it would cost about $2-$6or$10 you can get the supplies on ebay,radio shack,dump or junk yard for parts from cars old radio and also from old toys,radio. i got lots of parts at home
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Plz reply i luv the mini carbon cone woofer!
Nice Speaker M8 where did ya geddit from huh??!! I like the carbon Cone
fatrickuk (author)  creative zen6 years ago
I got my amp for GBP £10 and you could get the switch and the battery snap very cheap from a normal electronics store or order them on ebay. It only cost me £12 to make one. (Note that I took out the speaker from my old stereo so I wouldn't count that.)
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