PURPOSE: To prevent propagation of sound to a floor and also to keep beautiful outer appearance while being matched with the image of a room by packing a substance with high specific gravity to a thermosetting resin, forming the result into a block form and arranging it under a speaker.

CONSTITUTION: The substance with high specific gravity such as metallic powder of lead or iron, or inorganic powder such as barium sulfate or silica sand is packed to the thermosetting resin such as melamine resin, urea resin or ester resin, and further an optional coloring agent or stabilizer is packed and the result is formed into an optional block form. A rugged pattern is applied as required, a pattern is printed or a decoration sheet or board is adhered after forming while the resin block is not colored.