What is a subwoofer? Size, and surround material (polypropylene foam?) – What to Look For

Introduction human ear can hear sounds 20-20000 Hz frequency regularly. These include low-frequency instruments like drums and bass, mid-tones, such as voice and guitar-type instruments and high-pitched sounds such as birdsong and dishes. factory sound systems usually include, of course, AM / FM / CD with four speakers. Unfortunately, the speakers are usually lower pick [...]