I’m looking for guinea pigs who regularly ride with a pillion passenger (scooter, big bike, whatever) and would like to try out a new bike communication system.
The idea was to build a basic rider-pillion intercom with decent audio quality and features that doesn’t cost NT$15k like Autocom systems et al. It features 1 stereo input + 3 mono inputs + 3 mono outputs + regulated 12V supply per headset. Rider-to-pillion comms use up 1 mono input and output which leaves stereo input for CD player/mp3 and two connections for cellphone, CB radio etc which both headsets can use simultaneously.
Anyone who takes part will get a free unit that they can keep after the trial but will obviously be expected to answer some questions about how they found it. You will have to do the installation yourself since that’s the point of the exercise. Send me a PM if interested.
Oh, great, Llary. Just fucking GREAT! It’s not enough now to have the constant drone when I’m driving the car – “watch that truck. He might change lanes. There’s somebody behind you. Maybe he’ll want to pass. You should let him. We have to turn off up ahead. You should be in the other lane…” Now I’m supposed to be subjected to it on the bike, too? NO thanks very much!
Full duplex filtered. This is aimed as a budget full-featured system for tourers/commuters and doesn’t work as well as more expensive VOX/active systems much over 70mph. Active stuff like Autocom is indeed high quality but a complete waste of money off the racetrack and we reckon we can get out a full two-rider system for half the price of an Autocom base unit. My circuit uses a high quality power supply and cheap, off-the-shelf amplifier ICs which is cheaper and works better than very high quality amps with dirty power.
I’ve tried a bunch of VOX systems either for bike-to-bike or for air-to-ground, and they all sucked, basically. For an intercom, filtered would be the way to go I think.
Oh, one little trick I learned from building free-flight headsets: In a walkie-talkie set up you can put the mic into the headphone housing with the speaker, since you don’t run duplex. Inside a helmet, the mic doesn’t have to be in front of the mouth, and hidden away up there you have virtually zero wind noise. I have tested those on a motorcycle, though not at very high speeds. With a duplex system you may have feedback issues though… anyway, it’s an idea to play with.
[quote=“redwagon”]I’ve tried a bunch of VOX systems either for bike-to-bike or for air-to-ground, and they all sucked, basically. For an intercom, filtered would be the way to go I think.
Oh, one little trick I learned from building free-flight headsets: In a walkie-talkie set up you can put the mic into the headphone housing with the speaker, since you don’t run duplex. Inside a helmet, the mic doesn’t have to be in front of the mouth, and hidden away up there you have virtually zero wind noise. I have tested those on a motorcycle, though not at very high speeds. With a duplex system you may have feedback issues though… anyway, it’s an idea to play with.[/quote]
The whole reason I got started on this was that I wanted a full duplex handsfree rider-pillion system with cellphone, music and 2m radio hookups. I was looking at all the systems available and realised they were charging NT$15k and up for what was essentially a cheap audio mixer/amplifier/intercom. After a lot of experimenting I worked out the quality of the audio amplifiers is nowhere near as important as the mics, headphones and power supplies. So might as well save money on the amplifying/mixing circuitry and spend it elsewhere.
PTT sucks for rider-pillion because the whole idea is hassle-free communication that doesn’t take your attention off the road. VOX is almost as bad because it’s impossible to set up for the range of conditions you would expect on a long trip. Those integrated mic/headphones work great and you can build a high quality feedback suppression circuit with a single IC and handful of components.
