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Sound and acoustics
Keep in mind that sound is waves of air. Sound has a couple of common parameters you have to know.
Measured in dB (deci Bell), this is the volume of the sound or how high the sound waves are.
dB is a logarithmic scale which means that if a guitar amp is playing 83 dB and you put another amp of the same model and setting in the room, they will not be playing 166 dB but at 86. So 3 dB is actually the double amount of sound.
The scale starts at 0 dB because this is the weakest sound most humans can hear.
Make sure to read the ‘Hearing’ chapter about sound levels.
Frequency is measured in Hz (Hertz). This is the length of a sound wave. A human hearing reaches between 20 and 20 000 Hz where a low frequency is a sound with a lot of bass and vice verse. Your register is gradually lowered with your age, especially in the higher regions.
Cables and Jacks
Here is a list of the most common cables and their name(s):
¼ inch jack – The jack used for almost every guitar and keyboard. Also known as ‘TRS’, ‘Tele’ or just ‘Jack’.
XLR – used for nearly every microphone and mixer. Also known as ‘Cannon’
RCA – Usually found in home stereos or dj mixers (and other stereo mixers) Sometimes called ‘Phono’ or ‘chinc’.
3.5 mm Mini jack – used mostly for computers and mp3 players. Watch out for the 2.5 mm mini TRS. Also known as mini TRS and mini tele.