The United States, the world's biggest oil consuming country, consumed 18.5 million barrels of oil per day (mbd) in 2012, which accounted for nearly 20% of the world's total oil consumption per day. The highest level of oil consumption in US history was 20.8mbd, which occurred in 2005.
It is also important to be conscious of the speakerâs sensitivity rating, measured in decibels (dB). The higher the number, the less power a speaker requires in order to reach higher volumes without distortion. For most car speakers, this number typically ranges between 88 to 92 dB.
The woofer driver is responsible for low, bass frequencies. Deep, pulsating notes come from the woofer. In technical terms, the range of a woofer is between 20 Hz, the lowest range of human hearing, and 1,000 Hz. However, some woofers that have to cover part of the mid-range can operate as high as 5,000 Hz.Subwoofers are a type of woofer that plays the very lowest frequencies.They operate from 20 Hz up to 120 Hz.n technical terms, the range of a woofer is between 20 Hz, the lowest range of human hearing, and 1,000 Hz. However, some woofers that have to cover part of the mid-range can operate as high as 5,000 Hz.