The design of acoustic filters will be reviewed along with 1-D wave propagation in pipes. For 1-D wave propagation, information required to understand filter design will only be covered. Also, along with covering filter design for ideal long wavelength filters (using lumped element method); a number of practical filters which could be implemented will be covered. Real life examples will be shown to relate theory to practice. Other topics briefly touched upon could include impedance relations, power transmission, resonance, attenuation, or lumped elements.