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.
For example, if you're going with a 3 way setup with a subwoofer, a midrange, and a tweeter, and voices usually fall in the 200hz-2500hz range, then ideally wouldn't the midrange driver be crossed over lower than 200hz and higher than 2500hz, so that you don't have voices coming through more than one speaker?