The Vibrating Floor

 
IMG_0312.jpg

Pretty much since I started working at Three Ways School, nearly ten years ago now, I have had my eye on a cavity which was built into the Sensory Studio floor. It was pretty much sealed in and over the years I have done investigations and tried to get hold of missing plans etc to find out what is down there. Over the last couple of years I started work in earnest and got some budget to create a vibrating floor.

Having come up with a rough design I set about trying to find a carpenter willing to take on the project. Once I had detailed my requirements, mostly I found that the carpenters stopped returning my emails and answering my calls. However, Andy Emmerson (Emmerson of Bath) was made of sterner stuff and agreed to take on the build.

We built a floating floor mounted on rubber supports and powered by two powerful shaker motors. These motors can be driven with low frequency audio meaning you can feel music with very limited audible sound. Andy did a great job on the frame, there are no rattles and the floor moves freely for a great responsive and very powerful vibration.

I am currently working on a suite of tools for using vibration effects with SEN children and will eventually link the visual floor projection with the underlying vibration events.

Designing electronic instruments - 2

Following on from this post.

On Monday we met to discuss the first prototypes of the two instruments we wanted to explore as detailed in the previous post. 

The Filter Box

We took a look at the first Filter Box prototype as seen in the pictures below which was set-up in a temporary box for testing of the sensors. I bought several small wooden boxes to try for size, shape, and general ergonomic-ness when holding, and to enable discussions as to what might be good features and functionality to have in the box. 

Our idea was to create a wireless filter box. I wanted to use some of the nrf240l1 radio modules I have acquired as they provide a very cheap mechanism for wireless communication, and there are lots resources available to make them work with Arduino. A detailed tutorial on using Arduino + Nrf24l01 running into Max/MSP software can be found on my website here

Discussing the box!

We discussed:

The wooden boxes I had purchased and selected a small oval shaped one as the best shape and size to fit in the hand. 

Buttons- having some (x2) to enable more functionality- options included click buttons that would provide tactile feedback when depressed or valve style that would more naturally mimic an interaction with an instrument such as a trumpet, like a valve, these would give feedback not as obviously as a click but more suited the instrument paradigm. 

Adding a force sensitive resistor (FSR) that could then be pressed harder or softer to achieve some of the effects you would with other instruments such as when fretting a guitar, and allow expression through fingertip movement and pressure of the hand on the box. The mapping of the FSR could then be naturally connected to something like the amplitude of the sound so when pressed harder the sound would be louder, again going with what a player might naturally expect from an interaction of that style. 

Light dependent resistor (LDR) this worked well as a mechanism to control some sort of filter, or for example the mute of a trumpet, the cutoff frequency of the sound or the volume. This is taking the movement of the opening and connecting it to any kind of parameter that might need fine movement and can be used to get effects like vibrato and tremolo. A parallel can also be drawn between something like scratching (dj style) by opening and closing the lid, and when connected to a filter controlling some element of feedback, using noise as the sound generator. We had a little play with using the light dependent resistor to control the cutoff frequency on a filter over sounds and using the motion to trigger MIDI notes but felt that the latter did not really play into the strengths of the opening and closing of the box as much as the controlling of an effect. 

The aim with the filter box was to create something that when held in a natural position would allow access to the 2 buttons and the FSR as well as facilitating the opening and closing of the lid so that the elements could be used in conjunction with each other and separately in an ergonomic way. 

The Pressure Box

We discussed the pressure box and using an array of piezos arranged around the bottom of the circular wooden box to create 8 potential pressure points. The Arduino pro mini we are using in the instruments allows for 8 analogue inputs so would suit this set-up. The box can then be filled with foam and topped with a soft tactile yet spongy material such as neoprene, or potentially some sort of skin stretched over the top in the style of a tambourine and secured down with pins. Being that the piezos are very sensitive to vibration there may be some cross talk between the 8 units but this could provide useful for expression. The sensitivity of the piezos allows for tapping the box to trigger or modulate the sound also. 

Future boxes

The hexagonal box though not used yet could potentially feature a new mode of interaction for each of its faces to allow a player to choose their preferred interaction mode and mechanism, this may be one for future exploration.

Next Steps

I will now review what we have discussed and implement them into some more prototypes! 

The Musii - Threeways School, Bath

Threeways purchased a Musii a little while back now and have had some great sessions with it. It has 3 inflatable prongs with built in distance sensors and LED lighting and makes musical sounds as you press them in. The software runs on a little built in Linux machine and it is all self contained with an amp and speaker inside meaning it also vibrates. I always find that sound needs to be local like this for a meaningful experience, rather than coming out of a speaker over there on a wall which can be a little abstract. Since we have had the unit it has been updated to make the sounds less discordant which has helped, but the only other issue we have had is access. Wheelchairs can not get very close to it, but the company are very open to critique and they are apparently looking at something more lap based. Personally, I'd love these to be coming directly out of the floor or the wall!

3D Sound work - Threeways School, Bath

Today we worked with a PMLD class in the Threeways Sensory Studio using 3D sound. The studio is an egg shaped room with 12 speakers (3 high and 3 low on each side) and we have created some software that allows us to assign different sounds to each speaker and control the volumes via an iPad interface. There were some really interesting reactions and it is proving to be a useful tool.