Vocopro DA2277 User Manual

 A/V is an abbreviation for Audio/Visual.

 Any type of connection that splits a signal into two parts. An example would be a connector with 

one male RCA jack on one end, and two female RCA jacks on the other end.

 A speaker, (driver), used for low-frequency reproduction. Usually larger and heavier than a midrange 

or tweeter. 

 A speaker, (driver), used to reproduce the middle range of frequencies. A midrange is combined 

with a woofer for low frequencies and a tweeter for high frequencies to form a complete, full-range system. 

A speaker, (driver), used to reproduce the higher range of frequencies. To form a full-range system, 

a tweeter needs to be combined with a woofer, (2-way system), or a woofer and midrange, (3-way system). 

 Or Pre-amp is a device that takes a source signal, such as from a turntable, tape-deck or CD 

player, and passes this signal on to a power-amplifier(s). The pre-amp may have a number of controls such as 

source selector switches, balance, volume and possibly tone-controls. 

 When speakers are mounted in reverse polarity, i.e., one speaker is wired +/+ and -/- from the 

amp and the other is wired +/- and -/+. Bass response will be very thin due to cancellation. 

 CD players, VCRs, Laser disc Players etc., are connected in a system at line level, usually with 

shielded RCA type interconnects. Line level is before power amplification. In a system with separate pre-amp 

and power-amp the pre-amp output is line level. Many surround sound decoders and receivers have line level 

outputs as well. 

 The range of human hearing is commonly given as 20-20,000Hz (20Hz-20kHz). One hertz (Hz) 

represents one cycle per second, 20Hz represents 20 cycles per second and so on. Lower numbers are lower 

frequencies 

 To increase in level. The function of a volume control. 

 Named after Alexander Graham Bell. We perceive differences in volume level in a logarithmic 

manner. Our ears become less sensitive to sound as its intensity increases. Decibels are a logarithmic scale 

of relative loudness. A difference of about 1 dB is the minimum perceptible change in volume, 3 dB is a 

moderate change in volume, and about 10 dB is an apparent doubling of volume. 0 dB is the threshold of 

hearing and 130 dB is the threshold of pain. 

 Refers to a type of distortion that occurs when an amplifier is driven into an overload condition. 

Usually the "clipped" waveform contains an excess of high-frequency energy. The sound becomes hard and 

edgy. Hard clipping is the most frequent cause of "burned out" tweeters. Even a low-powered amplifier or 

receiver driven into clipping can damage tweeters which would otherwise last virtually forever. 

NOTE: The low VHF TV channels (2 through 6) are not used for wireless microphones and do not need to be considered