In a Nutshell – The Noise Gate

The world of effects is a vast and complex one, a world that remains a mystery to many but that we guitarists must master if we are to find our own sound. From overdrive to chorus, from tremolo to boost... the possibilities are endless, and this complexity is compounded with each additional link in the chain. Effects are available in many guises today, with rack-mounted devices and software on our computers; however, we will concentrate on good old fashioned pedals.

This month we'll take a look at the noise gate. It might be a stretch to call it an 'effect' but without it you could be in a pile of trouble...

The Science
A noise gate is used to remove or at least limit background and extraneous noise from an audio signal chain. Put simply, it ensures that sound that falls beneath a defined volume is removed or 'gated' and not permitted to pass. A threshold is set above the level of the 'noise' to clean up an electric guitar signal. 'Release' settings can be tweaked to change how quickly the gate closes. It can be abrupt and cut the gated sound dead, or more gradual so as to fade it out over a defined period. How you use it depends on application but for processed electric guitar sounds, or for signal chains that are prone to static, you pretty much want it all gone. The 'attack' setting dictates how quickly the noise gate moves from closed to open and works like a fade in. In many modern noise gate products designed for the guitarist all of these settings are pre-defined and optimised for electric guitar use so all you have to do is stamp on it.

In Use
Perhaps obviously, pointing to famous examples of the absence of noise is not an easy thing to do. Noise gates are used extensively by guitar players as well as sound engineers and producers for live work as well as recording. An obvious example of noise gating in the non-guitar world would be the drums on 'In the air tonight' by Phil Collins, where reverb has been added and is then gated rather than being permitted to decay over a longer time period. I use a noise gate when I'm using a very hot distortion but inevitably some dynamics and nuances are lost – I like to keep the threshold relatively high when I am using it to remove the worse excesses of the noise whilst retaining the tone and character of my playing.

Products
The best solution to the noise problem is to design your signal chain so as to minimise or eliminate noise, but that means a great deal of thought and buying top end gear end to end. Even if you do this chances are you will need one in certain situations. If you're playing clean or even with a mild overdrive you'll be OK but the more pedals you add to your collection, the greater the mess of cables and likelihood that you're going to get some static and background noise. All bets are off playing live as well – each venue will have wiring with a charm all its own...

Most multi-effects processors come with a built in noise gate, so some of you may not even have to consider this addition. For those who do most pedal manufacturers offer a noise gate in the range. The BOSS NS-2 noise suppressor is a good budget choice at £69.99 / $69.99. All settings outlined above are available, and spending a few minutes setting it up is worthwhile. It has noise detection circuit which helps to preserve the attack and envelope of the instrument's sound and at this price point it's hard to beat. I have used one in the past and the only criticism I have is that I'd probably need more than one were I to try to use it live. Set it up for some gating on a rhythm sound and everything is great but then hit your hot channel for some lead and everything gets buried in mush.

The ISP decimator is my current choice, and although about twice the money of the BOSS I have yet to find anything comparable. The marketing blurb on ISP's website cites 'Time Vector Processing' and 'HUSH' technology which basically means that the unit responds to your playing in real time and removes extraneous noise without colouring your tone.... or removing the colour in this case. It is very simple to use, having only one control, and the 'G' version is optimised for guitar so you're getting results straight out of the box. The decimator retails at £159.99 / $149.99 but it is the ultimate in quality – it is based on the THS/Rocktron technology but even their noise gates in my opinion are not this good.

To conclude, using a noise gate is a necessity in some situations but I would encourage you not to rely on it too much. It can take all the character out of your sound, as well as masking shoddy playing – excusable sometimes but not all the time. Take time to experiment and only use it when necessary – not all noise is bad...