Magnadyne WR30B | 3 Inch Dual Cone Speaker w/ Grill - Polypropylene Woofer Cone 2.8 oz Magnet is sold as a pair in both black or white colors. The speakers are waterproof and full range compact speakers with a 180Hz - 20,000 Hz frequency response, 50W max power. The 100 microfarad (uF) capacitor on the speaker wire will filter out audio signals below 180Hz from the speaker (Low Base Tone). This idea is to prevent the small speaker cone from moving excessively trying to produce low frequency that it is not capable of producing. This filter will minimize speaker distortion from Bass tones. The technical name for this filter is called a “High Pass Filter." The filter allows audio signals above 180hz to play.