Construction of the mNAP in Delhi. Visible is the timber stud construction, which is – on this side of the box – not yet filled with rockwool. Also visible, the high-spec heavy duty caster wheels.
The box built in Delhi was a beta version of an earlier model that we developed in a much more ad hoc fashion in Ahmedabad. I will outline both designs although the model built for the unbox festival in Delhi was much better in terms of reducing external sound levels. So, what what follows are instructions on how to build your own soundproof box.
The Ahmedabad mNAP
The first attempt of this box was more a statement of intent rather than a real soundproof box (although it was successful on many levels!). It was a relatively low key and also cheap construction which was mainly due to it being made from found materials (and having had a much better network of knowledge around us in Ahmedabad). It was designed to catch the eye when moved through space (which it did!) and to act as a sign as much as a mobile experimental space that got people talking about their everyday experiences of sounds in their lives.
The first design was determined by tight external parameters: time (from idea to design to construction and taking it into the field: 5 days) and a very limited budget. We had to be very resourceful and made use found things (scrap material from the yard of the National Institute of Design were we were based) and borrowed ones (the bicycle rickshaw that carried the box).
It was the bicycle rickshaw – it’s loading area and the capacity for carrying goods – that determined the shape and weight of the box that we designed. To cancel out as much sound as possible, it is important to have mass. If you have a vehicle that can carry a solid concrete box, this is ideal. If you are, however, like us, limited by what your vehicle can carry, you should consider a sandwich construction: a series of layers, fixed on top of each other, to ‘break’ sound – to make it as difficult as possible for sound to come through.
The sandwich of the Ahmedabad box was quite thin. In other words, it didn’t have the mass required to cancel out exterior sound. It consisted of a timber stud construction (40 mm), covered with one layer of mdf (8 mm) on the outside. Fixed to the MDF, in-between the studs – was sheeted material (15 mm) that is normally used in interior fit-outs when there is a need to absorb sound. Then, an air gap (35 mm) and another layer of MDF on the inside of the stud wall (5 mm).
To add sound absorption, we put a ‘tea-cosy’ (a custom-made cover of stichted-together matresses) over the box, and on the inside, we added a matress for sitting on and also covered the smooth mdf walls with a whitish fabric.
One of the most crucial details to consider is the door – or other entry point into the box. If this detail is weak, i.e. fits too loosely, then all other efforts are in vain. The door here was one that could be taken off in its entirety. It had door handles on the outside which allowed us to lift it up, in place and slot it in.
The Delhi mNAP
From the beginning, the Delhi mNAP had a much more technical feel to it. We had a sound consultant who advised on the number and kind of layers, the thicknesses of materials, how to design corners and so on. It was driven by a desire to make it as ‘good’ as we could in terms of cancelling out sound. Whilst we weren’t able to get precise measurements on the actual reduction of noise levels (it was too quite inside for the decibel meter to pick up a measurement), it was markedly better.
But, then, it was also much more expensive. Due to its construction – again a timber stud sandwich construction with an overall thickness of almost 120 mm (as opposed to the 53 mm of the Ahmedabod mNAP) – the box was not only bigger (resulting in more material use) but also much more heavy (around 400kg). This had consequences for transportation.
Whilst, ideally, I would have liked the box to be as mobile as the bicycle rickshaw, the practicalities of it became unfeasible within the time-frame and budget available to us.
We ended up fixing high-spec very costly caster wheels to the bottom of the box, which allowed us to wheel it around, but within a limited range. Due to the size of the city of Delhi, the condition of roads and the traffic congestion, we ended up having to transport the box from one location to another with a man (the box was lifted onto the back of a truck by 8 men!) and then rolled into position.
Doing it again, I would design it in a way that would make attachment to a small car possible – or, to motorise it as such. This would not only allow for the box to be moved around with greater ease but also to make it an object that becomes part of its space around it.
The decision to paint the box black was maybe taken too quickly. Whilst it allowed people to use the box as a noticeboard (for the paint was blackboard paint), it certainly seemed much less joyful and maybe much less welcoming then the previous mNAP.
Drawings for a do-it-together box of your own to follow.
