Bicycle Sound Systems (BSS) are growing in popularity. Anyone who has gone to a festival, seen or participated in a Critical Mass ride or watched the Skyride events in the UK will have seen a BSS in operation. The following is a description of what I have learnt over the years in the art of building a sound system attached to a bicycle.
Please note that all this is just my opinion; there are no rules. If it works and you or someone else is happy with the result then that is great. Duke Ellington once said, “There are two types of music, good and bad. If you like it, it’s good music.”
The first consideration before building a bicycle sound system is to ask yourself exactly what is it for? Now this may sound like a stupid question but consider:
Is the music for your own enjoyment, other cyclists riding with you, or members of the public watching?
Will you be riding the bike whilst the music is playing? (probably answered in the first question)
Would you like to play just your own music or have facilities, i.e. mixing desk, microphones, to make the system more flexible?
Would you wish to hire out the system at festivals and other events?
Where would the system be stored when not in use?
How would you get the system to the events?
Hopefully you can see the reason for asking these questions first. Once you know what the BSS is for, there are now a few more questions.
What is the budget?
How loud is the system to be?
Will you want to operate it in the rain?
Is it to be self-powered?
Would you want to use a trailer?
I am going to presume that the BSS is designed to have the music playing whilst being ridden. I have seen ‘static’ systems but I feel the whole idea of a BSS is that we have mobile music.
A top of the range BSS could run into thousands of pounds, especially if everything needed was bought new.
The volume of the system is probably the key to everything. The amount of power needed outside is far, far more than is needed inside; most of the sound from speakers inside a building is actually reflected sound. Take the walls away and the volume drops massively.
There has to be a balance between what is audible, the fidelity of the reproduction, what can be afforded, and what is practical. A super loud system can not only annoy the neighbourhood and attract the police but it becomes really heavy and is impossible to move. Remember there is not just the weight of the speakers, there are also batteries and amplifiers that have to be carried.
Again, how loud depends on the use, if it is just yourself and a cyclist next to you, 50 – 100 watts could be enough. In my opinion, 100 watts would be the absolute minimum. If you want many people to hear you and you want a proper bass response, the wattage must increase. I believe 600 watts is somewhere around the maximum, for both volume and weight.
Critically the amplifier must not be overdriven. This usually happens when the output of the amplifier is not enough for the situation. Everything is turned to max to compensate and there is distortion. We have all heard it, in cars, clueless DJ’s, PA systems… The crazy thing is that turning it down just a bit will reduce the volume very slightly but everything can now be heard properly without distortion.
The question of waterproofing has to be considered from the outset. Placing plastic bags or sheeting over speakers, amps and players does not work; not only does it look terrible, water WILL get in. Another issue is at what point do the covers go on? In case it looks like rain or when it starts raining? The latter means carrying covers to hopefully quickly throw over the system (whilst it is running!) in the hope that nothing gets damaged. Although there are waterproof players out there, the connections are not waterproof. Waterproof speakers do not sound that good, they are small and low powered. I have never seen a waterproof amplifier.
Self -powered or not? This will come down to the volume of the system. An average cyclist can develop 100-200 watts for an hour. Moving the bike and sound system is going to use a certain amount of that power. There are losses involved in converting that power to usable electricity. Taking these factors into account, never mind the engineering problems in generating the electricity, we do not have much left for powering the amplifier. It can and has been done, the systems are not that loud and, in my opinion, are not that good.
Whether or not to use a trailer is again down to what the BSS is for. We have all seen the ghetto-blaster strapped to the side of a bicycle. It works but the sound is not too good and cannot be heard from more than a few metres away.
The main problem with getting a decent sound without a trailer is one of weight. That is why all the good sound systems I have seen use a trailer.
If it is decided that batteries will power the system, we then consider the amplifier. Although the best amplifiers, in terms of fidelity are the domestic, Hi-Fi amps, they run on mains, 110v or 240v AC. This means the battery voltage, most likely 12v DC, must be converted.
This causes all sorts of problems. The worst is that cheaper converters, or inverters, convert the DC into a square wave AC, this makes an amplifier hum. The other problem is the idea of having high voltages running around the system.
Even if these considerations were overcome, the next, probably terminal issue is that a domestic or PA amplifier would probably fall apart in a short time due to the battering bicycle sound systems get. And they do get a battering; cobbles, pot holes, kerbs, speed humps, all give these rigs a hard life.