The bell of the Hwason fortress in the Korean city of Suwon is the national wealth and the city's pride. A huge bell hangs from a massive wooden frame low over the ground surface. People say that if you strike it with a blocky log and wish something, you will certainly have your wish. After the strike the bell vibrates and its vibrations are so strong that your palms ache if you put them on the bell. Lots of people wishing to strike the bell come there every day. The fortress is on the mountain top and its chime is heard from afar. The bell's vibrations sure are beneficial, but it would be very difficult to hear them many times every day. On the platform where the bell is installed the sound produced by the bell reaches a deafening pitch whereas at a distance of 100 meters it is almost unheard.
The problem is solved in the following way. A kind of a bowl-shaped cavity is provided under the bell. It concentrates the sound waves and directs them upwards giving a special depth to the bell tolling. In addition, such a concentrator does not allow the sound to propagate at a large distance thereby protecting the ears of the inhabitants of adjacent villages.  

In this case the a contradiction is resolved in space by using the physical effect “Concentration of sound”.