This is my planned/first build. Comments?


2010-09-16 1:02 pm
Im planning to mount some speakers behind me on my pedal bike.
I would like to have it be audible for ~10ft radius around me so that when I ride with people they can also hear it... plus its fun when im hanging out with my bike.
I dont expect great sound but I dont want it to be repulsive either.
The music wont stop when I stop pedaling... at least right away.
I bike in the rain when it rains and dont want my speakers to die/need babying.
I have a generator on my bike that I would like to be able to power the speakers as well as store power from my wallsocket or something.

Concerns (in order):
Weather proof-ness
Audio Quality

I dont have a detailed plan but the idea is that I will use:
-these 2 4" waterproof marine speakers pointing left and right of me. These are good for rain and 2 pointing left and right will give sound to all those biking with me.
- Limit bass to >150 hz or maybe >300 hz depending on the performance, use adjustible filter so i can tune it :)
- Limit high frequency if the sound is too beamy.
-A TPA3106D1 40W mono class D amp based on this build. I dont need stereo and it makes everything quieter. I would limit it to ~25W output to keep battery alive longer
-The amp needs 25V in so i will have a boost converter to convert the bike generator source which is ~3W @ 6V i think (I dont own it yet but possible modding could improve output)
- I will have a battery supply power to the amp so that I can have music playing at stoplights. The battery should last at least 1hr.

Nice to haves coming later?
- Hook a light up to my generator as well for when its dark.
- Solar panel to charge the battery?