Discussion

 

When this project started, our main goals where to create a parametric model of a mouthpiece which could be adjusted with the click of a mouse and an artificial mouth (AM). This artificial mouth could be used to eliminate the saxophonist while comparing mouthpieces. This is useful because a saxophonist immediately  adapts when he or she is given another mouthpiece. With an AM we could compare the sound spectrum of mouthpieces with different geometries with the exact same lip pressure, lip position and air pressure. Afterwards, when a saxophonist would describe how he or she thinks the mouthpiece sounds this would give us information about which geometrical aspects of the mouthpiece influence the sound in a preferred way and we could try to maximize this by looking at the sound waves. This in turn would be of use in for example printing personalized mouthpieces, which could be printed with the type of ‘sound’ the customer is looking for.

Even though in the end we were able to play the saxophone with a bicycle pump using our homemade mouthpieces, there were some minor and major problems which, in retrospect,  could have been prevented easily.

Planning is key. Although we had a concept for the AM relatively quick and knew how to build it mostly, nine out of ten times you  will come across some problems while making it though. For example, the lower lip mechanism was thought all the way through before starting to manufacture the definitive version. Also a test version was made to see how it would work. If all stages of designing the mechanism inside would have been applied to the rest of the box as well it would have come together a lot better in the end. So in a future research, when designing the AM, it would be a great start to make a complete CAD model of it before actually starting to build. This way everything would be dimensioned beforehand, so no calculations, even the simplest ones, could be done wrong in the workplace. In our model, this led to the wall thickness of the polycarbonate box walls not being taken into account. Which in turn led to having to eliminate the system to read out an X-value for the lower lip positioning system.

Don’t make assumptions. I.E. Our artificial mouth was designed using a 2 mm rubber gasket in between the walls and the steel. After cutting the steel, we found out only 3 mm rubber was sold at the inventory where we got most of our materials. Even though this meant just a 2 mm difference compared to our design,  this made it really hard to fit the polycarbonate walls into place and actually made the AM less airtight.

Another assumption we made was the availability of pressurized air, because there are air outlets through most of the building we tested in and at the start of the project there was a lot of talk about a pressurized vessel. This was to be able to use the AM in an acoustics room, in which there are no air inlets because it is a closed environment. However, we didn’t really take into account this air had to be build down from around 10-20 Bar to 30 to 60 mBar. This requires high precision air regulators which are hard to come by. These kinds of specialty equipment should be ordered long before starting to build the AM. A good guideline would be to try to have everything for the build there before the last week (in which the build takes place).

Although we made some small mistakes along the way we thing it was a good project which gave some great insights in how to build an AM which could do the research very well.

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