Studio Recording

Supported By

Audio Concepts: The Many Applications Of Gates

There are countless applications for gates and knowing how best to utilize the tool is key in crafting a quality mix.
This excerpt provided by Focal Press

This is the continuation in our series by Roey Izhaki on gates. Additional segments within the series are available here.

Removing noise
Noise can be introduced onto a recording in many ways.

Tape media, microphones, microphone preamps, any analog component or an A/D converter are just a few examples of systems that superimpose their own inherent noise on the signal.

When a recording is done in a domestic facility, background noise is also often an issue. Essentially, any signal that ever roamed the analog domain includes some noise.

Even purely digital signals, e.g., a bass line generated with software instrument, can incorporate either quantization distortion or dither noise.

Luckily, modern technology enables cleaner recordings than in the past, so much of the noise on today’s recordings is inaudible.

Generally speaking, if high-quality equipment is used, and used correctly, a gate for noise removal might not be needed at any stage of the mix. If, for example, the signal-to-noise ratio on a digital recording is 60 dB (noise level at −60 dBFS), chances are that the noise will not be a problem.

Even higher noise levels might not be an issue since in many cases the wanted signal masks it. Noise tends to be more noticeable with sparse arrangements and during the quiet sections of a production – in both cases there is less to mask it.

One thing worth considering is that noise can become more noticeable as the mix progresses.

Figure 11: Adding punch to a percussive instrument using a gate. The threshold is set to the base of the natural attack and the range is set moderate to large. The release together with hold will determine how quickly the natural decay is attenuated and in turn the overall length of the hit.

For example, after applying make-up gain on a compressor, the noise level would rise as well. Also, by boosting the highs of a specific track, the noise is likely to become more noticeable.

Even when the noise is audible, one must ask: what is wrong with a little bit of noise? Many people associate the synthetic sound of digital systems with the lack of noise and distortion.

In fact, some engineers deliberately add noise or distortion to a digitally clean recording in order to spell some of the familiar analog sensation. The noise in these cases might be similar to a tape hiss or even a crackling vinyl.

Nevertheless, other noises like those generated by hard drives or washing machines are a problem – they are unlikely to remind anyone of the familiar analog sound.

Some judgment has to be made as for what noise needs gating and what noise can tolerably stay.

Another point is that our ears find varying noise levels (breathing) more disturbing than constant noise levels. This fact is taken into account in many noise reduction systems.

We have to take this into account when gating a noisy track – varying noise level after gating might be more noticeable than the constant noise level before gating. Say for example we have a sparse arrangement with a noisy vocal track. The noise is likely to be masked or be less noticeable while the vocals are sung.

The challenge is to make sure that the gate opening and closing does not cause noticeable noise variations.

For example, once vocal drops below the threshold and diminishes, a slow release can cause a noticeable descent in noise level. If the vocal is sent to a reverb emulator, this drop might be even more noticeable.

Study Hall Top Stories

Supported By

TELEFUNKEN Elektroakustik’s mission is to design and build iconic microphones and modern professional audio equipment that provides classic sound for recording, broadcast, studio, and stage . Our vision is to be a global leader in emitting good vibes through manufacturing and design, all while capturing the spark of the TELEFUNKEN legacy and transmitting it with uncompromising quality.