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I have a treadmill desk and my downstairs neighbour is complaining about the noise. Specifically the noise made by the impacts of my walking. Unfortunately the floor of my flat is not concrete but made of wooden beams topped with a laminate floor: not a lot of mass to absorb the impacts and not much dampening either. So, I have to do that myself. Ideally I'd have a big slab of marble and a length of open/closed cell foam of just the right density and dimension and would sandwich that underneath the treadmill. I don't have and couldn't carry a big slab of marble, so as a stand-in I'm going with a large wooden board as thick as they come (or can be glued together). Say a kitchen countertop. What I can't figure out is: How dense does the foam need to be?

Given

  • a treadmill with a weight $m_t = 26\mathrm{kg}$ that occupies an area $a = 8555\mathrm{cm^2}$ ($59\mathrm{cm} \times 145\mathrm{cm}$)
  • a human with a weight $m_h = 70\mathrm{kg}$ walking at a steady speed $v = 3 \mathrm{km/h}$ with decent shoes for runners
  • a wooden board with the dimensions of the treadmill used to evenly distribute the impacts across the foam
  • open or closed cell foam occupying the same area as the board / treadmill

Arrangement

  1. Human
  2. Treadmill
  3. Board
  4. Foam
  5. Floor

Unknowns

I don't know the force of my impacts caused by the walking nor how much the shoes mitigate.

Resources

Reducing 3D Printer Noise

phdoerfler
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2 Answers2

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Its more the noise of the entire floor resonating with your jogging rhythm and vibrating as an echobox.

Even if you manage to soften half of the impact by a clever system of plywood and foam you delay the resonance by just a few steps.

Ideally you would need your treadmill in an enclosure on an expensive suspensions system.

kamran
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Your proposed arrangement will probably not be ideal.

putting a wooden board between the treadmill and the foam might make the board act as a speaker phone and make the noise more significant (in the room). This will be more evident if the mass of the board is small.

To give you a more intuitive example, think of taking a sheet of metal with certain weight and width (but different thickness) and vibrating it (across the thickness). As the thickness decreases (therefore mass also ) the noise will become much louder. There are some products that you can use for increased damping.

Additional problems you might encounter:

  • tilting of the board (if the foam is thick), when the center of gravity of man-treadmill changes.
  • if the board is not strong/stiff enough, having the treadmill on the board will probably create bend or break the board pretty quickly under daily use.
NMech
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