How to Build a Megaphone Bike Stereo

Cycling and music. These are two things I'm passionate about. Why not combine them?

On a scale of 1 to 3, this project ranks a 2 in difficulty. You'll need to be able to solder, desolder, identify a few components and adapt this design to suit your application.

Total Cost
My out of pocket costs were $6. The plastic, speaker, zip ties, misc. wire were either found or leftovers from other projects.

~1 hour once you have all supplies

From an appearance stand point - I give it a 9 out of 10
From a functionality stand point - I give it an 8 out of 10
From an audio stand point - I give it a 6 out of 10
From a loudness stand point - I give it a 7 out of 10
(A prior version of this would have had scores under 5)

As a side note - yes, this is technically not a stereo. Complaining about that is your prerogative, but I couldn't care less. If I say sharpie, you know it's a permanent marker - communication has been served.
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Step 1: Materials

Picture of Materials
1 Amplifier
1 Speaker
1 Power Supply
Misc. Wire
Headphone jack
Mounting Board


*$5 Harbor Fright Megaphone
*Free speaker from discarded boombox
*Batteries, AA's are fine - they need to put out ~6V (I later used a 6V gel cell) - you can also use the original battery pack if that suits you
*Wire, some wire came from boombox - I also used a Cat5 cable
*Headphone jack can come from a pair of headphones
  • For the mount, I used a piece of plastic that I then laser cut to fit perfectly into my bike rack - feel free to improvise, similar quality can be had using thin plywood and a jigsaw ;)
cheekyz2 years ago
Oooo... this is SO CLOSE to fulfilling a silly little dream... I want to pipe Barney & Mr Rogers' songs thru it as a poorman's karma, so to speak, thanking other drivers for sharing their music with me... will try to use cigarette lighter 4 power, not sure how to pipe it thru loud enuf to rattle their teeth like they do mine, but it'll be fun!!!
geebear773 years ago
If you put a baffle behind that speaker, you can double the volume and get a richer tone. I bought ready made from a car audio store, but you can just use tupperware.
trebuchet03 (author)  geebear773 years ago
In an open air environment, I'm not too worried about the richness of tone :) Plus, then only one ear is going to get sound ;) With the back end open, you get some form of audio coming out the rear.

Check out my profile, one of the smaller images is a later bike stereo build using 2 speakers on either side inside of an enclosure.
munkymoose4 years ago
Hey, great 'able! Would it be possible to make a stereo version of this by making two and using phono jacks instead of a microphone jack and link them up?
Brings back such good memories!

Stereo version in the near future?
trebuchet03 (author)  T3h_Muffinator4 years ago
Oh hells yes :p I've got a 400W amp stereo mount for the bike :p Much better than this first version, about 390 watts better :p

Eventually, I'll get around to sorting through pictures and documenting :p

Man... that looks so badass.  Hooked up a generator for the battery yet?
trebuchet03 (author)  T3h_Muffinator4 years ago
No :( It runs on a PbA battery and the amp is too big (heavy).... Somewhere down the line, I want to optimize for weight (which will likely mean efficiency too). Then I'll throw in some generator magic (that bike even has a mount for a side roller headlight generator) :p

How'd the awesome grant project turn out? Can cotton candy be launched great distances yet?
Awesome man, I can't wait :)

It's coming!  I'm down to figuring out how the electronics have decided to destroy themselves over the winter, and turning a venturi tube out of teflon.  I really really want to be done by Maker Faire Boston, which is in April!

Pics and more to come when I'm done :)
I'm Jealous of your Recumbent !

I might have to make my own
paganwonder4 years ago
Cool 'ible!    Your side note at end of intro completely ROCKS!!!

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