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 speaker sensitivity, typically expressed in decibels (dB) with 1 watt (or 2.83 volts across an 8 ohm speaker) measured on-axis one meter away. Typical values are 85-89 dB for bookshelf speakers, 87 to 92 dB for floorstanding models, with high efficiency speakers in the 93 to 100+ dB range. If you are not sure, try 90 dB as a default. (Pro equipment has sensitivities as high as 111 dB!) 2. The amplifier rated power per channel, expressed in watts.