TL Audio 5050 - Manual (Page 12)

input gain can then be gradually increased until the output level LED bargraph
illuminates to about 0dB on normal signal level. The master output level
should then be adjusted to produce the required output.
4.6 Line
Input.
A line level signal should already be at about the correct operating level, but
this may be checked by monitoring the level on the output meter, with the
compressor bypassed and the output gain at 0dB. The input gain should be
adjusted until the meter reads about 0dB at normal audio level.
4.7 Instrument
Input.
The front panel instrument input socket is suitable for low level sources such
as hi impedance microphones, pick ups or passive guitars, and higher level
sources such as active guitars and keyboards. To cater for this wide variety of
sources, the 5050 has a large amount of gain available, and care should be
taken to avoid applying excessive input gain with a high level source.
4.8
High Pass (Low Cut) Filter.
The high pass filter switch restricts the low frequency response of the preamp,
to effectively remove rumble or LF noise from the signal. The filter can be
useful in restricting “popping” on vocals or even low frequencies caused by
contact with microphone stands or microphone cables. Popping is an
undesirable thump that is caused by close-miking certain spoken or sung
letters, namely “P” or “B”. These particular letters cause a sudden expulsion of
air that can result in an audible thump. As this thump has a lot of low
frequency content the high pass filter can help to reduce the problem, as can
using a pop filter (a device usually made out of nylon material similar to
stockings) suspended in front of the microphone.
4.9
What is Compression?
Compression is an essential but often misunderstood process in modern
recording. Put simply, compression reduces the difference between the
loudest and the quietest levels of an audio signal. This is known as reducing
the “dynamic range” of that signal and is a powerful tool for an engineer
helping to avoid overloading, distortion problems as well as raising the level of
the quieter parts of the audio signal. Before the introduction of compressors
the only way this could be achieved was by “gain riding”, whereby an engineer
would control the fader manually in order to try and anticipate very large levels
(which might distort the signal) or very low levels (which may get lost in noise).
The introduction of compression devices meant that this process could be