The Noise Gate & Amplitude Modulation (AM)

The noise gate is software that is used during the recording to signal audio. The noise gate works like a tool to eliminate the noise, the dirty sound in audio signal that we want doesn’t hear. Is used in a processing of record with whatever instrument, either a guitar or drums, bass, voice or another instrument.

The amplitude modulation is a technique used in electronic communication, conveying information through a wave. Basically it allows you to transmit information from one point to another without the sender and receiver is connected physically, most commonly for transmitting information via a radio carrier wave.

WHAT’S NOISE GATE AND HOW WORKS?

The noise gate is software that is used during the recording to signal audio. The noise gate works like a tool to eliminate the noise, the dirty sound in audio signal that we want doesn’t hear. Is used in a processing of record with whatever instrument, either a guitar or drums, bass, voice or another instrument.ng100-noise-gate_4cfd603cc0e16

The concept is very simple, the noise gate works like a normal door. When we have the signal audio recorded and we want edited for eliminate the dirty sound or ecos, background noise, little sounds after a break/stop.

We have a signal audio and when we use noise gate this function like a wall, a threshold. Any sound that doesn’t exceed the threshold established is considered useless noise and then this sound is eliminated. All audio signals that exceed the threshold will be useful and good sound. The noise gate doesn’t delete the sound magically, the noise gate hides the sound, so that the audio signal disappears and is not heard in the recording.

To understand the concept of noise gate we need understand some other terms or concepts related to noise gate, to understand how works this. The concepts are threshold, ratio, attack time, release time, hold time and bypass.

Threshold: Is the limit, the barrier we put on the audio signal, and then the signal that surpasses it is heard, and the sound signal that is below stays in silence in the recording. noise-gate-2

Ratio: Attenuation is the amount that we give the signal is below. With ratio we can choose how many decibels (dB) reduces this noise.

Attack time: The time it takes to activate the noise gate, so the times to open the gate of the sound signal that we want to pass the threshold and finally hear on the recording.

Release time: The time it takes to close the noise gate. The time it takes to prevent the signal audio that is below the threshold established doesn’t hear on the final recording.

Hold time: The time that the noise gate remains open after the signal audio has gone below the threshold. The hold time is just before the release time and serves to decrease softly the closing of noise gate. The main function of hold time is to soften up the closing of noise gate, so it doesn’t close too much directly, and thus not losing any sound that we want to hear on the sound recording.60seconds-gates-2

Bypass: It is the tool that allows us to compare the original audio signal with the audio signal processed with the noise gate. It’s a very useful tool, and then we use the software noise gate, always we must click on the button bypass, to really hear the changes that occurring to the audio signal recording.

How to use a Noise gate?

WHAT’S AMPLITUDE MODULATION (AM)?

The amplitude modulation is a technique used in electronic communication, conveying information through a wave. Basically it allows you to transmit information from one point to another without the sender and receiver is connected physically, most commonly for transmitting information via a radio carrier wave.

To understand the concept to way more simple, amplitude modulation is the form that radio worked. Send as modulated electromagnetic waves to transmit and demodulate our receiver (radio) for which we receive information.fig_2010_07_01 In order that a steady radio signal or “radio carrier” can carry information it must be changed or modulated in one way so that the information can be conveyed from one place to another.  A number of ways in which a carrier can be modulated to carry a signal, is often an audio signal and the most obvious way is to vary its amplitude. Is defined as the process of change or modulate the amplitude of a carrier frequency.

This process consists of two parts. The first is the modulation that transformed the information in its original form to a form suitable to transmission. That is, the module information to convey it in a wave. The second part of the process is the detection and demodulator to recover the transmitted information in this wave. It is necessary the existence of a transmitter, a communication channel and a receiving device. Both the transmitter and receiver must be adjusted to the characteristics of the channel. Captura de pantalla 2014-10-29 a la(s) 17.50.48 Amplitude modulation is the most straightforward way of modulating a signal. Demodulation, or the process where the radio frequency signal is converted into an audio frequency signal is also very simple. An amplitude modulation signal only requires a simple diode detector circuit. The circuit that is commonly used has a diode that rectifies the signal, only allowing the one half of the alternating radio frequency waveform through. A capacitor is used to remove the radio frequency parts of the signal, leaving the audio waveform. This can be fed into an amplifier after which it can be used to drive a loudspeaker. As the circuit used for demodulating AM is very cheap, it enables the cost of radio receivers for AM to be kept low.

Prezi: http://prezi.com/txvpfadw5zww/edit/#0_30863873

Bibliography:

http://www.doctorproaudio.com/content.php?140-puertas-ruido-noise-gates

http://es.wikipedia.org/wiki/Puerta_de_ruido

http://www.productormusical.es/puerta-de-ruido/

http://whatis.techtarget.com/definition/amplitude-modulation-AM

http://www.textoscientificos.com/redes/modulacion/amplitud

http://es.wikipedia.org/wiki/Amplitud_modulada

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