J. Noise Gates

Noise Gate vs. Hard Gate

There are two noise suppressors on the Pod HD, the standard "Noise Gate" and the more advanced "Hard Gate". In general I prefer the Hard Gate, because its a true gate. The Noise Gate is part gate, part signal processor and can result in "tone suck". At higher settings, it tends to make the tone sound thinner.

The Noise Gate uses less DSP than the Hard Gate; however, so sometimes it's the Noise Gate or nothing, and I use it with lower settings then.

Gate Overview

Here's what a noise gate is designed to do - either let signal pass through or block it completely. It's helpful to think of it like a physical gate. When "open", the signal should pass through untouched as though the noise gate isn't even in your signal chain. When "closed", no signal should be allowed to pass through. The gate detects the signal's volume level, compares it to a threshold setting, and determines whether the gate should be open or closed.

Most gates also feature a Decay parameter. This specifies how quickly the gate should close - whether the signal should fade out over time or be abruptly silenced. a 0 setting means the signal should jump from the threshold level to no output. Higher settings fade out over the specified time period.

Some gates feature a Hold parameter. This keeps the gate fully open even after the signal level diminishes to less than the Close Threshold. After the hold time is elapsed, if the the signal level did not return above the Open Threshold, the gate starts to close at the speed specified in the Decay parameter.

Open/Close Thresholds

The Hard Gate has two threshold levels - open and close. If the gate is currently open, it is only looking at the Close Threshold value to determine if it should close. If the gate is closed, it is only looking at Open Threshold to determine if it should open. This helps in two ways.

Single threshold gates are subject to jitter - consider a sustained note that is gradually decreasing in volume. The level you hear might be 96, 95, 95, 95, 95, 95, 94 db at 1/20th of a second intervals. The level the gate detects might be a little different, let's say 96, 95, 94, 95, 94, 95, 94. If the Threshold was set to 94.5 db, the gate would open and close rapidly as a decaying note hit the threshold value. It would sound like sputtering, which is very noticeable and undesirable.

With separate Open and Close Thresholds, you can set them a few db's apart, and the imprecision in the effect's signal level detection will not cause a sputtering gate.

This also comes in handy due to guitar naturally having a strong attack. Setting the Open Threshold high means when the gate is closed, you won't accidentally open it with soft noises you make when you're not trying to play a note, such as your fingers rubbing on unfretted strings. Yet, once you do purposefully play a note, the attack is strong enough to open the gate. Setting a single threshold gate to such a high threshold would mean that sustained decaying notes would get "cut off" rather than naturally fading to silence. With a low Close Threshold setting, however, you can let the note decay to almost silence before the gate closes.

While you can fake the above technique with a single threshold gate by turning up the Decay parameter, it's more favorable to set Decay lower and use two tresholds. It sounds better, and you'll get the expected gate behavior when you're playing quick staccato notes or sustaining notes.

Hold

The Hard Gate also features a Hold parameter that specifies a time to hold the gate open even after the Close Threshold has been passed. This can be used to reduce jitter as described in the last section, but as mentioned, staggered Open/Close Threshold settings should take care of that.

Where I find Hold is useful if you are using a longer Decay time. If you are playing a staccato part, the fade-out of the noise between notes is very noticeable, compared to if the noise were to remain at a constant level. Setting a hold time is basically taking a little time to make sure the gate should really be closing.

Decay

For a spacious lead tone, where any decay is going to be buried by reverb or delay, I like to turn Decay a bit off 0 such as 100-200ms - so there's not an obvious sound when the gate kicks on. For super tight rhythms, I like it at 0; but this means I have to be careful about my muting and exactly where I set the Threshold(s).

Placement in the Chain

As far as placement in the signal chain, I find the most effective place is first in the chain - most of the noise in your tone is coming from the low signal-to-noise ratio and hum produced by guitar pickups. Anything that is compressing the tone in your chain, such as compressors, distortion pedals, and amp models, are amplifying that initial noise. You might think that this would mean to put them last in your chain (or after a compressing element), but then they are very difficult to dial in.

Note that the signal from your pickups is going to by the most dynamic, which makes it best for dialing in gate settings. If you only place a gate after some kind of compression, it will be difficult to find settings that let only let your playing through and not noise but still allow all your playing through.

Dialing it in

To dial in the Hard Gate, start with Hold and Decay set to 0 ms. Set both Open and Close Threshold around 9:00 (about -70db) - easily opened but still high enough to make the gate close when muting. If the gate won't close at these settings, turn them both up until the gate closes with the guitar muted, but with its volume knob at 10/10.

Then I see if I can make the gate open using a mundane noise, such as tapping a string, or rubbing a string with my finger. If so, I turn it up a bit. Once I've gotten it high enough so it won't open from any incidental noises and intermittent hum, I see if it will open by playing the softest note I intend to play. This varies from patch to patch. For a soft lead patch, this might be a mild hammer-on onto a silent string. For my Meshuggah rhythm patch, it's going to be a picked note at at least medium strength. If it won't open, I have to turn it down, even if this means it will also open from incidental noise as I play. Better for it to pick up some incidental noise than block out purposeful playing.

Then I back down the Close Threshold. I want to test it against punchy staccatto notes and chords as well as sustaining notes. I need it to activate between my stacatto playing but not kill a sustaining note; however, these are conflicting goals.

The "middle ground" I choose depends on the patch. For a soft lead, I want it low enough to sustain notes as long as possible. This means I have to make sure the guitar is completely muted to get the gate to close, so I have to pay more attention to doing so if I'm trying to play stacatto or after I let a note decay. For my Meshuggah patch, I want to make sure it activates as soon as I mute the guitar, even if my mute didn't have perfect technique. I'm not sustaining many notes for very long, especially single notes higher on the fretboard which are more sensitive to decay. So long as it doesn't cut off a sustained power chord after a few seconds, I'm happy.

I leave Hold at 0 ms. The Hard Gate is precise and quick enough so that I don't have to worry about trailing noise when quickly muting the guitar from a loud volume. Since I set Decay to a very low time, I don't need to worry about hearing a fade-out of noise either.

If I can get away with setting Decay to 0 ms, I'll do that, but if the gate kicking on creates an unnatural tone, I'm going to either need to use two gates, or introduce a little Decay. I set it just barely off 0, at like 20 ms. The slight decay prevents an unnatural cut-off sound, but it's not long enough so that you hear noise fade out after staccato notes. If it's not tight enough, we'll have to use two gates.

Dual Gates

Using two gates is useful when you're using strong compression or distortion, and you need to go from punchy chords to dead silence very quickly. I like to place the first gate as the first thing in the chain. I dial it in as described above, but it may not kick on fast enough, and those snippets of noise occurring as I'm muting are being amplified and are obvious when listening to the tone.

I add another gate after the compressor/distortion stage that is adding most of the compression. For many people, this is the end of the chain. For me, it's usually before the amp, but after a compressor or distortion effect with a little drive. I dial this one in exactly like the first one, and I turn the first one off while I'm doing so.

Once I've got them both tuned, I try the patch out with them both on. Sometimes it'll end up gating a little too much. I tend to back off the first gate a bit, while keeping the final gate firm.

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