Introduction: SOLO Cup Speaker

Picture of SOLO Cup Speaker

Want to be the life of the party this year? Or maybe, like many college students, you want to blast your music way too loud. Awesome. You're in luck because I've designed this SOLO Cup Speaker to bring out that college student that's inside all of us. Because, what is a party without music? And more importantly: what is a party without SOLO cups? So let's kill two birds with one stone, and get that party bumpin' with a raging party worthy SOLO Cup Speaker.

This little red cup has a huge sound. Built using a real plastic SOLO cup, this project isn't like similar cup speakers. The plastic of the cup is used to resonate bass frequencies to give this party animal some passive bass boost. Since I know that many are all about that bass, I didn't stop there. I modified this speaker's amplifier circuit to give it punchier lows with an active bass boost. Equipped with an indicator LED, internal amplifier, volume control, 1/8 inch audio jack, 2.1mm DC jack, and 8 ohm speaker, this cup is all you need to get rowdy. You can even throw your cup into your backpack with a 9v battery and bring your party with you wherever you go!

So come on, the party awaits! Let's move onto our next step to find out what you need!

Step 1: Get Some Parts, Bro!

Picture of Get Some Parts, Bro!

You're going to need these parts:

-One SOLO cup

-LM368 (with socket)

-Perfboard (5cm by 7cm)

-8 Ohm Speaker

-220uF Capacitor

-100uF Capacitor

-10nF Ceramic Capacitor (Code: 103)

-33nF Ceramic Capacitor (Code: 333)

-47nF Ceramic Capacitor (Code: 473)

-10k Ohm Resistor

-Two 4.7K Ohm Resistors

-10 Ohm Resistor

-47K Ohm Resistor

-2K Ohm Resistor

-5K Ohm Potentiometer


-2.1mm DC Screw-Mount Jack

-Red 3mm LED (with bezel)

-1/8 inch Audio Jack

-Assorted 22AWG Hookup Wire

-Gorilla Glue (or Super Glue)

-Some Tape

-Dupont Female to Female Wire

-Male Headers

-SPST Switch (Optional for ON/OFF)

You'll need these tools as well:

-Hot Glue Gun (with glue sticks)

-Wire Stripper

-Soldering Iron (with rosin)

-Rotary Dremel Tool

Step 2: Breadboard It!

Picture of Breadboard It!

Before starting a project, its best to breadboard it first. Even for super awesome party speakers. So lets start this off with some breadboarding!

Attached in the images above is a "schematic" of the circuit we will be implementing. A schematic is basically a map of what goes where in a circuit. If made correctly, they should be easy to follow so don't get discouraged! Wondering what the symbols mean? Here is a reference.

The circuit we are going to implement amplifies the low voltage audio signal coming from the input device and outputs it to our speaker. The heart of this project is the LM386 audio amplifier chip. It provides surprisingly good quality audio amplification in a small package.

(Note: There should be a speaker connected in the images of my breadboarded circuit; however, due to styling reasons I left it out. Follow the schematic if you are ever uncertain of what is correct.)

If you have trouble getting your circuit to work, check out the next few steps as they may help you see what's going on with the circuit.

If you're not satisfied with the sound of your speaker, try swapping speakers. Keep in mind that the cup will resonate the lower mid and bass frequencies.

Once your breadboard can blast some tunes, let's get soldering!

Step 3: Solder IC Socket

Picture of Solder IC Socket

Alright! Now that we know what we're doing, let's get soldering. Solder your IC socket near the center of your perfboard. This will give us room to fill the holes nearby with our other components.

IC sockets are very useful in projects that heavily rely on a certain integrated circuit, since if the chip goes bad, you can just swap it out for a brand new one!

Step 4: Solder Pin 1 Connections

Picture of Solder Pin 1 Connections

For simplicity, we are going to take things one pin at a time. So lets go ahead and start with pin 1. Refer back to the schematic for visual instructions.

Pin 1 is connected to pin 5 via your 33nF capacitor and 10K ohm resistor (polarity does not matter).

Great! Now we've got some electronic components on the board. Now for a little tip. I am going to assume you take this advice from now on:Make sure when you have long resistor/LED/capacitor/etc leads protruding from your board that you cut them with a wire cutter (see picture 4). If you don't remove them now, they will probably end up sitting there forever... kinda like that homework you and I are putting off.

Step 5: Solder Pin 2 Connections

Picture of Solder Pin 2 Connections

One pin down, five left to go. Let's check out pin 2:

Pin 2 is connected to our mono audio input via a 10nF capacitor.

For now, let's now worry about converting the stereo input to mono. Connecting your 10nF capacitor to pin 2 is enough for this step. However, go ahead and add three male header pins to connect the audio jack from the cup to our main board. Also, add another two male headers for ground and the input voltage, as we will be using them in the next step. See the images above for more details!

Step 6: Solder Pin 3-4 Connections

Picture of Solder Pin 3-4 Connections

Take a breather... this step is easy. Simply do the following:

Connect pin 3 and 4 to ground.

That was too easy. To make things more exciting, also add two male headers for the speaker (opposite from the audio input) and add another two headers for connecting our indicator LED later on.

Nice! Now our main board is really coming together, but we are missing a key feature... The power supply! Let's check that out in the next step.

Step 7: Solder Power Supply

Picture of Solder Power Supply

Its time to take a break from the LM386 and instead focus on the board's power supply. We must go through the trouble of adding a power supply on the board because we want to be able to input a variety of voltages to our speaker to make it more versatile. A simple way to accomplish this is to use a LM7805. The 7805 is a voltage regulator. The job of a voltage regulator IC is to knock an input voltage (between a certain range) down to a constant documented voltage. This makes it so that we could give this circuit 12V, and the circuit would be just fine.

LM7805's have a simple pin out. Check out here for a diagram and further explanations.

Just connect the input ground to 7805's ground (middle pin), input voltage to 7805's input, and the output voltage will be the regulated power supply for our circuit! While you're at it, connect one LED indicator header to 5V via a 2K ohm resistor and the other to ground. Alright now we can get back to our LM386!

Step 8: Solder Pin 5-6 Connections

Picture of Solder Pin 5-6 Connections

Just two more pins remain for us to play with on the LM386. Check out the connections on the schematic and the following textual instructions:

Connect pin 5 to ground via a 10 ohm resistor and 47nF capacitor. To continue we will need to solder three headers to the mainboard to represent the left, right, and middle terminals of our potentiometer. Connect pin 5 to our 5K ohm potentiometer's left terminal via a 220uF capacitor. Connect the middle terminal to one end of the speaker's male headers and finally the right terminal should be connected to ground.

Connect pin 6 to +5V and a 100uF capacitor connected from pin 6 to ground.

That's it for the LM386! Just one more piece and the circuit will be complete. Move onto the next step to finish the circuit!

Step 9: Sum Stereo Audio Signal to Mono

Picture of Sum Stereo Audio Signal to Mono

Stereo audio is an electronic signal which has two channels: left and right. It gives a spacial aspect to reproduced sound and is great for speaker systems that consist of more than one speaker. However, since our cup only has one speaker, we are going to want to transfer both the left and right channels of our stereo signal into one single channel.

This cannot be done simply by connecting the left and right channels together. Attempting that could lead to shorts and some bad phase. (Imagine if the left channel was high and the right was low). To prevent this (or at least lessen it), I've implemented a circuit I found online into the main board. Check out the schematic above for visual instructions. To sum the stereo signal into mono you have to:

Connect the left and right channels together via two 4.7K ohm resistors. Then connect their sum to ground via a 47K ohm resistor.

Don't forget to connect pin 2's capacitor to the newly summed audio signal!

Sweet! Now we have both the left and right channels of our stereo signal coming out of a single speaker. Now we just have some loose ends to tie before we start working on that SOLO cup!

Step 10: Solder and Connect Dupont Wires for I/Os

Picture of Solder and Connect Dupont Wires for I/Os

Let's finally make use of all those headers by connecting our inputs and outputs to them. Strip the ends of our dupont wire and solder them to each external component. This includes: the potentiometer, speaker, DC jack, 1/8 inch audio jack, and indicator LED.

Once complete be sure to test your circuit to make sure everything is up to par. Be prepared for your speaker's sound to be beefed up by the cup's natural passive bass/lower mid boost!

Step 11: Cut Perfboard

Picture of Cut Perfboard

To make the circuit fit in the SOLO cup, we are going to need to cut off any parts of the circuit that are taking up unnecessary room. In my case, I could get rid of an entire half of the board. To cut your perfboard follow these steps:

1. Scratch the board with a utility knife multiple times.

-This weakens the board at the exact location where we want to break it.

2. Using a pliers, firmly grip the side of the board you want to keep. While keeping your grip firm, push on the other side of the board with your other hand. It should break nice and even. (See picture 3).

3. Try to put your circuit board into a SOLO cup and see if your board needs additional trimming. You could always use a dremel tool for some quick shaving.

Good news! The circuit is totally done! Now its just a matter of hanging out with that red SOLO cup for a while.

Step 12: Dremel SOLO Cup

Picture of Dremel SOLO Cup

Using a dremel tool, make room for your potentiometer, indicator LED, DC jack, and audio jack. Here are some precautions while dremeling the cup:

-Be careful not to break your cup, and make sure to have several backups just in case.

-Make sure to space out the components well so that they do not touch inside of the cup.

-For each drill hole, ensure that the component fits snug without being too loose that it could slide into the cup and without being too tight that it cuts through the plastic cup.

Step 13: Mount and Glue I/Os

Picture of Mount and Glue I/Os

If dremeled correctly, this step should be simple. Everything should fit just right and screw in nice and tight. However, since we are all human, there may be some drill holes that were too large. To fix this use super glue or gorilla glue to ensure that those components are going no where. This prevents you from over tightening screws so that there is no damage to the SOLO cup.

WARNING: Do not use hot glue when securing components to the SOLO cup! See picture 3 for the effects of hot glue on a plastic cup. It could cost you a lot of time if you accidentally burn through your cup!

Step 14: Connect Mainboard and Mount Speaker

Picture of Connect Mainboard and Mount Speaker

All that's left to do is hookup our female wires to the male headers, secure the speaker to the cup, and then finally rock out to some ill beats!

Using a tweezers or small needle nose pliers, attach the dupont wires to the appropriate male header. Be especially careful of the polarity so you don't short out the circuit. Try not to pull too hard on the wires as they (and the cup) are quite fragile.

Once the mainboard is attached to all the I/Os, all thats left to do is secure the speaker. To do this you could use glue, tape, velcro, or some sort of metal lock. I decided to use tape, since I'll be opening up this cup to show/demo it to others and... its cheap! Roll a small amount of tape onto your finger to spread the adhesive on all sides. Line the bottom of the speaker with tape, and carefully push it against the top of the SOLO cup.

Radical! That's one gnarly SOLO cup speaker. Just one more step left: to party!

Step 15: Go Party!

Picture of Go Party!

Finally, you can go hit up all the parties on campus blasting your hipster house music or dope beats in style! Or even listen to music alone and pretend you're partying! Either way, you've got a pretty unique hip SOLO cup speaker. I hope you've learned a bit about audio amplification, stereo/mono audio, schematics, and using the dremel. If you enjoyed this instructable, please support me by voting for this instructable in the University, FormLabs, or Tech Contest! Thank you for your interest in my project!


melcan (author)2014-10-02

Very cool. Gorilla Glue works great but foams up and looks kinda weird, so I tend to go with Super Glue. Thanks for sharing!

bergerab (author)melcan2014-10-02

Good point! I just chose something that would "work", but super glue is probably the best solution. Thanks for the suggestion!

Yonatan24 (author)bergerab2015-10-30

The super glue might melt the cup

JM1999 (author)2014-10-11

I really appreciate the work you have put into taking photos of the circuit board and not just drawing diagrams, very good job on the 'ible and congrats on the win!

tkleinauskas (author)2014-10-06

Cool, I like this idea!

diamondmine (author)2014-10-05

Sorry having some trouble understanding the pin out of the chip. Where is your pin one and eight? sorry just it's a little flipped around for me

bergerab (author)diamondmine2014-10-05

Its totally ok! The schematic is pretty small and hard to read. I'll try to make the pin numbers larger in the future. However, Pin 1 is connected with a 33nF capacitor and 10k ohm resistor to pin 5. And Pin 8 actually has no connections! If you ever have trouble reading the schematic, I explain each step of the schematic in the steps above. Thanks for bringing this to my attention!

petar17 (author)2014-10-03

How long will play with one battery ?

Ginko Balboa (author)2014-10-03

DIY in its essence!

draite (author)2014-10-02

This is an awesome project!

poorjohnn (author)2014-10-02

So cool

s3cur17y (author)2014-10-02

Nice. I would see about using a ps3 battery and making it rechargeable. but still an awesome project.

bergerab (author)s3cur17y2014-10-02

Yeah great idea. Unfortunately I don't have too many small rechargeable batteries (with charging electronics) available. Next time I implement this project, I'll be sure to do that, as well as, add some bluetooth functionality. And I challenge everyone else here to do the same! Thanks for the comment

Dulexy (author)2014-10-02

Great job!!!

Tater Zoid (author)2014-10-01

Red Solo Cup: The Next Generation. I love it.

nodcah (author)2014-10-01

Great Instructable! Nice background change! XD

bergerab (author)nodcah2014-10-01

haha thanks! I've been learning about CSS, HTML and all of that recently. Thanks again for your HTML instructable!

tomatoskins (author)2014-10-01

And your pictures turned out great as well!

seamster (author)2014-10-01

Nicely done!

Jonathanrjpereira (author)2015-12-11

How did you change your Instructable background to RED?? So cool!

IamOrion (author)2015-11-02

where can i get the parts? all the radioshacks have gone out of business. I love blasting my music, so i would really like to do this.

ctwistedpair (author)IamOrion2015-11-27

tayda electronics. Sells just about everything u need. If you like em on facebook, they give u discounts

ctwistedpair (author)2015-11-04

nice setup. I cant read tue pins on the ic chip on your diagram. They are blurred. Can you post a darker diagram please. Id like to etch a copper board for this. This would be a cool birthday gift. Thank you!

lneves (author)2015-11-03

Nice project! Could you explain a little bit more or give some references for the schematic? I didn't undestand some of its parts..

andianjul (author)2015-11-02

Hi great instructable. I am wondering, however, why you included the 7805 power supply (and associated components)? I looked up the specs for the LM386 and they indicate that it will run on 4 - 12 volts, so you could run it straight of the 9v battery (or plugpack).


carla.howe.10 (author)2015-11-02

Awesome projects! I love using these ideas to teach STEM

SoudZ made it! (author)2015-10-31

good and nano cool project me to working on that type

wellabovezero (author)2015-10-30

Yeah, this is awesome... but how about some links to where to get the parts? Maybe I missed that somewhere.

marcosr7 (author)2014-10-13

Can I go with the tl082 instead the lm386? Is because I have the tl082 around my desk and I feel lazy to go to RadioShack.

wobbler (author)marcosr72015-10-30

A bit of a late reply, but if you've tried it you'll know that the answer is no. Although the circuit block diagram for the lm386 and the tl082 may look the same (they are both effectively op amps), the lm386 is designed for high power output, the tl082 isn't.

petar17 (author)2014-10-03

How long will play with one battery ?

Yonatan24 (author)petar172015-10-30

It probably depends on the volume...

wobbler (author)Yonatan242015-10-30

And the battery!

According to this data sheet, the LM386 gives a maximum output of 1W at 16v voltage supply under max distortion and output. This would mean (assuming an unrealistic100% efficiency just to get a rough figure as the data sheet gives conflicting results on the efficiency) that it is taking approx 62.5mA from the battery. If we assume it's only 50% efficient we can knock this up to about 125mA, so a 16v 1Ah battery would last approx, 8hrs. From the data sheet, using an 8ohm speaker and lower voltage at a reasonable distortion the power out is limited to about 300mW so the amp should last about 3 times longer or about 1 day at max power out for every 1Ah of the battery. As it probably won't be run continuously at max power, the technical answer is "quite a long time".

ref: datasheet

jmuncher (author)2015-10-30

Great idea for a cheap, portable speaker. I've made them in the past for pocket guitar amps, is there a benefit to dropping the voltage down to 5V? I think the LM386 is rated for 15V, you can crank that speaker up if you get rid of the LM7805. Might not sound as clear, but you can add a variable gain by adding a 1k potentiometer between pins 1 and 8. Supa bass!!

wobbler (author)jmuncher2015-10-30

I was about to comment on why the 7805 but it looks like you beat me to
it. I can't see any advantage in using it. It doesn't allow you any
greater range of input voltage and complicates the build. It may also
result in more power loss (and hence less battery life) as it will be
continually wasting (V-5)/V % of the input voltage which will only be
heating the 7805 up at the expense of power which could be powering the

RickT17 (author)2015-10-30

Each time i try to download the instructions, i get an anoying add to sign up for something pro. It won't go away.

xtracycletony (author)2015-10-30

Nice work young man, now get back to work!

Yonatan24 (author)2015-10-30

First of all, Your pictures are amazing! What do you use as a white background?

If I have to guess the SOLO cup isn't really good at acoustics, especially with the bass... It might also bend or break

Also, If I made such an awesome project I would go ahead and use a rechargeable 12V battery (rechargeable 9V batteries suck) You can buy a really good 1.8 Ah 12V Li-Ion battery on eBay here:

Or other amperage's:

I really like these batteries, I've used them for a couple of my projects!

Aubrienna (author)2015-10-30

Awesome instructable! It will make a great project for me and my Dad (He's good with circuits and building things- he's actually built his own computer- and I love music and speakers and doing stuff on the computer) I'm confused though, you posted this a year ago and it's just now getting featured? I thought only new instructables got featured. Don't get me wrong! You totally deserve to get featured.

I actually got featured, which really surprised me since I'm barely 13, and it happened right after I posted it. Hmm. I Really like that you used a SOLO cup- did you know those where on sale for 50cents at Walmart not that long ago?

Oh, and do you think it would work with a bigger one, or a smaller one?

Really awesome 'ible.

RaymondR6 (author)2015-10-30

Excellent job! This reminds me of when I built my own stereo headphones using two transistor radio speakers, two empty Parkay margarine tubs, a wire clothes hanger, and some foam padding. I did this because headphones were too costly for me in the 1960's (as a child with a measly allowance), and they were heavy but I enjoyed them until I began summer jobs and bought a good Realistic headphone set at Radio Shack.

Your project can be upgraded if you add a small Bluetooth receiver inside and make it truly wireless.

Mayukh281 (author)2015-10-30

Does it have clear sound?
I loved the idea and would really try makeing it if it has a very clear voice

bergerab (author)2014-10-04

Sorry you feel that way about this project. For those of you reading this comment, this instructable demonstrates a proper use of an amplifier circuit and is an excellent beginner and intermediate project. It is very cheap (cost me less than $5). While some may not agree, using perfboard is the most efficient way to make this project. It is more cost effective than buying etching materials and solutions for such a tiny circuit such as the one shown in the schematic. There will always be people who disagree. However, thanks for giving your prospective.

bergerab (author)bergerab2015-02-01


WixNotxProduct (author)2014-12-04

What speaker did you use?

bergerab (author)WixNotxProduct2015-02-01

I used an 8 ohm speaker that I salvaged from a small yamaha keyboard. You could just find a goodwill or thrift shop, they usually have small keyboards with suprisingly decent speakers!

rpharaud (author)2014-10-25

Nice project idea! Quick question though... for the breadboard circuit, it looks like you only have four caps as opposed to the five in the circuit diagram. Also, did you use the 220uF at all?I want to build this, but I want to make sure that I understand the breadboard part before I proceed any further. Thanks again for this idea!

Chuck Stephens (author)2014-10-14

Nice one! This is so 'college'. I'll have to make one for my brother in law who majored in keg stands at FSU.

GeekScientist (author)2014-10-07

great i like it....Thanks for sharing

petar17 (author)2014-10-03

How long will play with one battery ?

petar17 (author)2014-10-03

How long will play with one battery ?

About This Instructable




Bio: I'm a student at UW-Milwaukee studying computer science with a passion for electronics. I'm always working on a project or thinking of new ... More »
More by bergerab:Flame Controlled MIDI ControllerSOLO Cup SpeakerBackpack Anti-Theft Alarm
Add instructable to: