Introduction: Spy Megaphone Hack

Picture of Spy Megaphone Hack
Take an ordinary megaphone and turn it into a bionic hearing spy device.

Get the same Megaphone here to build your own!

You will also need a 1/8" audio jack and a pair of headphones/earbuds. Some wire and standard tools, soldering iron, snips...etc.

OPTIONAL: 1/8" Y-Adapter and MP3 Recorder or other small device with Line-input.

Step 1: Disassemble the Megaphone

Picture of Disassemble the Megaphone

1. After opening up the battery compartment you will see 1 screw. Remove it and the battery compartment and circuit board assembly will come out as one piece.
2. Unplug the 3 connectors. Make a note where the white connector is as there are 2 2-pin connectors.
3. Remove the 3 screws that hold the body to the horn and remove the body.
4. Remove the single screw in the center of the horn. This will release the speaker.
5. Drop the speaker out and remove the 3 screws holding the horn on to the speaker
6. Unsolder the two connections at the speaker. Remove the speaker and save the white 2 pin connector.

Step 2: Modify the Microphone

Picture of Modify the Microphone

1. Remove the two screws that hold the microphone case together and unsnap the case.
2. Using a sharpie, make a mark on the microphone's black wire. That's the Negative (-) connection. Also, if you look closely you can identify the Negative connection by observing the traces that go to the microphone case.
3. The microphone should pull out from the case insert. Put it in a safe place.
4. Drill a small hole in the side of the bottom microphone case to fit the 1/8" audio jack.
5. Solder the red (+) and black (-) wires to the positive (+) and negataive (-) contacts on the audio jack.
6. Install the jack in the case and close the case, reassembling it with the screws.

Step 3: Modify the Horn

Picture of Modify the Horn

Next, we will be installing the microphone in the horn.

1. The microphone will not fit in the existing screw hole in the horn that held the speaker so it needs to be drilled out. A 7/16th drill bit works perfectly. Carefull drill out the hole.
2. Insert the microphone in the hole and seal it with some hot glue.

Step 4: Modify the Wiring

Picture of Modify the Wiring

1. Cut the white/clear wire and the red wire about 2 inches from the 4-pin connector.
2. Solder the two white wires from the 2-pin white connector wire we removed from the original speaker (Step 1 #6) to the two loose ends of the white/clear and red wires you just cut. (Don't solder it to the two remaining wires on the connector)
3. Cut two lengths of wire about 6" long. Solder one wire (in my case, black) to the white/clear wire and one (in my case, red) to the red wire at the 4-pin connector.
4. Solder the other ends to the microphone in the horn. Red to positive (+) and black to negative (-).

Step 5: Re-assemble the Megaphone

Picture of Re-assemble the Megaphone

It's time to put it all back together.

1. Re-assemble the body to the horn with the three screws.
2. Plug the 4-pin connector back on the board and the 2-pin white connector. Leave the black connector unplugged as that is the Siren and we won't be using that.
3. Install the circuit board/battery compartment.

Step 6: Start Spying

Picture of Start Spying

1. Install the batteries and close up the case. Attach the microphone to the holder and insert your headphones.

2. Try it out! You should be able to hear a pretty good distance away. I got about 100 feet of distance.

Additional Tips: If you used a better microphone you would probably achieve a greater listening distance and audio clarity. Paint the Megaphone either black or camo.

I hope you enjoyed this Instructable! Have fun, be safe and use this responsibly.


TOCO (author)2009-04-11

mythbusters is my favorite tv show!!

M4industries (author)TOCO2009-04-26

Did I really fool you? On accident of course. Trust me I am NOT Jamie Hyneman. If I was, my name would be M5 Industries, not M4 Industries. Just to clarify.

no it would be M8 industries they moved from M5 to M8 industries they moved 500 meters away due to space problems

No. Wasn't it the build team (Tori, Grant, and Kari (and Jess)) that moved to a place called M7. If there is an M8 then I must not have heard about it.

I'm so sorry i think they did and it was M7 500 meters away due to space problems
but.......... imagine walking that back and forth all day long

TOCO (author)M4industries2009-07-05

I know I was just telling you that it is my favorite show. I wish that you were Jamie Hyneman that would be cool!

Rhayel72 (author)2010-08-22

no, because ; the mic is technically the new speaker, and the old speaker is the new mic. So you'll just make your ear drums catch on fire :D LOL

sjoobbani (author)2010-02-13

 Wouldn't it be possible to use the speaker and then wire the siren to the speaker...

exabopper (author)2009-06-16

I just finished building my own version of this. To anyone who is going to build this device, I recommend strongly that you use the exact model of megaphone that Kipkay uses, and is shown on his website. Its construction is modular and makes for a much easier build. I went with a "Jobar Mega Mite" which is smaller - its horn diameter is slightly wider than a DVD. It was much more integrated and I needed to do a lot more soldering and fiddling to get it to work. I needed my Dremel tool to cut through circuit traces to disable the siren, and my speaker and cone were not easily disconnected from the unit, I needed to cut them out with the Dremel (which destroyed them). It isn't immediately obvious in Kipkay's instructable, but you need to discard the center white cone and the speaker (with its cone), so the mike is naked in the middle of the megaphone bell. My resulting spy mike has a loud hiss at all volume settings, but is very directional and will pull in sounds. It also makes a great stethoscope! A revision of its electronics will be my next project.

craig3 (author)2009-04-19

If yiou wanted to make a super one, could you buy a bigger microphone for it, or make any adjustments to make it more powerful?

shark54 (author)2009-04-15

this is a rip off

destructables28 (author)2009-04-13

imagine if we combined all of his listening- type devices

Bartboy (author)2009-04-10

Yay! I think you make some of the easiest to follow instructables. What type of camera do you use?

Kipkay (author)Bartboy2009-04-11

It's a Sony HVR-V1U. Thanks!

Bartboy (author)Kipkay2009-04-12

Cool! Do you use the same camera for still photos?

Sandisk1duo (author)Bartboy2009-04-12

seems to me that he took the pictures off of the video

Plasmana (author)2009-04-12

nice one kipkay! And I have a question, why are you making so many spy gadgets? Are you a spy or something?

MilotisX (author)2009-04-12

great job again kipkay! how much is the megaphone?

bookworm007 (author)2009-04-11

Looks like a cool reverse engineering project. I won't touch it because morally it's wrong to invade other peoples privacy.

roughly (author)bookworm0072009-04-12

hey bookworm007 ever thought of running for office ? - i wish everyone thought like you do. the world would be a better place.

Kipkay (author)bookworm0072009-04-11

Under any circumstances? How about national security or intelligence?

Yerboogieman (author)2009-04-11

My dad made a big cone and we could hear the neighbors PERFECT from our house, then i don't know what my dad did with it.

M4industries (author)2009-04-10

Ha! You really wouldn't want to plug in that third clip. The Moral: 120 Db doesn't exactly sound pleasant! Not that I have ever done it...

rimar2000 (author)2009-04-10

Very interesting. Any years ago I maked a passive megaphone using a washing machine spare, that of horn shape whit three paddles on a vertical axis. I cutted partially the edges, removed two paddles and maked a big elongated hole for the hand to the other. It was very useful.

ste5442 (author)2009-04-10

Nice work - very well documented!
I guess you could get a similar effect with a parabolic satellite receiver dish, or two of them worn as 'Mickey Mouse' ears so as not to draw unwanted attention to yourself :-)
I think the shape of the megaphone structure is more atuned to audio frequencies though ;-)

PCB Police

mweston (author)2009-04-10

Great project yet again, the link to the same supplies you used is definitely helpful too hope to see some more instructables soon!

Berkin (author)2009-04-10

Wow... I could think of a million things I could do with this excellent project... Great job, Kipkay!

About This Instructable




Bio: Tinkerer, hackster and prankster. Hit me up on Facebook: Thanks for checking out my Instructables!
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