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.
humans can hear frequencies from 20 20 000hz though this range narrows with age and is most sensitive around 2000 3 000hz the frequency range of speech this is why most people concentrate on the vocal over anything else in a song it occurs in the frequency range our ears are most sensitive to