Help Designing a Resonance Box for Tuning Forks

[KedarMhaswade]

TL;DR

I need to get a resonant box made for these tuning forks. Please let me know if my design looks alright.

I got these tuning forks from someone.

However, I do not have the resonant box for amplification of the sound. I decided to get it made so that I can experience the fundamental frequency (and other harmonics) more clearly.

I am planning to provide this design.

In summary, the box would be open on both sides and I would make the provision of various "slits" that are, say, 2 mm wide in which about 2mm wide "plates" would be press-fit making a "movable" fixed end of the box. For a frequency of 256Hz, this would give me a length of $λ/4$ = $\frac{344}{4×256}$ = $\approx 33.6 \space cm$ for the standing wave antinode to be created at the open end of the box.

Thus, one of the plates would be inserted into the slits at the lengths of my choice. Does it look like a reasonable design?

My specific questions:

1. How thick should the ply of the box be?
2. How about the other two dimensions of the box, if I am aiming for a reasonably loud resonance?
3. How do I fix (removably) the forks on top of the box? I suppose I should get the forks threaded. The threaded portion would then get fixed on a female threaded portion that is on the box.

 

[tech99]

The easiest way to make the fork audible is to touch it on to a thin wooden surface, or maybe the box they are stored in. This then provides a large area to couple energy to the air. It does not have to be resonant. I think the box you are considering may not be precise enough to hit the exact resonance. To couple the energy from the tuning fork, you are going to fix it to the wooden box and I am not sure about this method. I think the fork needs to be held across the open end of the resonator. Remember that a fork radiates edge on, and there is zero radiation broadside on due to the phase of the vibrating tines.