Using on drum triggers to trigger gates on mics

[Wease]

Had a gig this evening where the sound engineer placed triggers (Roland ones) on my snare, bottoms of toms, but not kick (I think) to trigger gates for the corresponding close mics. I’ve never had this done before, and speaking with him whilst setting up he said it was the best way to trigger the gates effectively without losing dynamics of playing. Kit so7nded good tonight and quite tight, it’s a quite dead stage anyway. What I’d like to ‘now is how does the informati9n flow work. Would he have fed the triggers to a drum module? How would the actual trigger signals get to the gates? I’m presuming standard type gates or Midas ones…it was a Midas digital console. Does anyone have any info or place I could find out more? And is this quite a common practice nowadays? Mid size well known midlands venue. Thanks very much
Love Wease

[The Elf]

'Drum triggers' are essentially just microphones, but they are used close in (often attached) to each drum to produce a signal with a lower level of bleed from other sources. That 'tighter' signal can then be used as a cleaner 'side-chain' source for a noise gate. This gives a more reliable gating behaviour.

In the studio I've often used this technique, not only for gating the same source as the trigger (snare and toms are common targets), but also for opening room mic's from a snare trigger, for example, or for lifting the send to a reverb - also for gating the under-snare mic. There's no need to feed the trigger to a 'drum module' of any description - all you're doing is routing the trigger audio to the side-chain of a noise gate.

The triggers can also be used to play a different drum sample for drum replacement, or enhancement (which could make a live sound engineer's job easier). On some occasions I've added the actual trigger audio to help enhance my drum mix, heavily EQ-ed to isolate the stick attack. In this context the quality of the trigger audio is not so critical.

How your engineer was using those triggers none of us will be able to tell exactly, but given that you liked the result it would be worth asking them for more details.

While we're on the subject I will also point out that I use a similar 'clean trigger' method for recording electric guitars: I almost always record a DI, to not only enable me to quantise the amped/processed guitar sound, but to also to give me a cleaner source for a gate trigger, should it be required.

[Wease]

Hi elf
Thanks for the reply
I’ve used drum triggers on stage before, triggering samples, but not triggering gates. Sounds as if there was a direct feed to the gates side chain input then

I was quite curious about the mechanics….i shall try to get hold of the engineer again and ask!

He [the engineer] did say they were just on and off switches, which kinda confirms your theory of what was happening

What gates do you use? Is there a particularly “well liked” gate for this kinda thing?

Thanks again
Wease

[The Elf]

Well, I'm not a live sound engineer, so I can only comment on my studio habits...

To clarify, when your engineer talks about 'on/off switches', I'm sure he is referring to the action of the noise gate, not the trigger signal. It would be a poor trigger device that didn't allow for velocity/level-related operation. Typically a gate looks for a signal crossing a threshold, and this is where the on/off operation is relevant (though it's not actually so clear cut!). If the trigger was used to play a drum sample you would hope that it would track level to the volume of the sample played.

Long gone are the days of my using hardware gates. Back in the day my weapon of choice (and that of seemingly half the planet) was the Drawmer DS201 - made 20 minutes down the road from here, in Rotherham. That remains the best designed hardware gate I ever used. They were lightning fast in operation, and had their own in-built side-chain hi/lo filters - which could be monitored to be used as a static filter for other purposes. They were beautifully simple in operation.

Nowadays I could imagine your engineer was accessing the side-chain in his mixer's software gates, but you would have to confirm that.

[Wonks]

The Roland drum triggers aren’t mics but look to be some sort of piezo device that operate from direct vibrations from either the drum head or shell, rather than spaced away and picking up audio.

They’d normally be fed into a TD module of some sort, but I assume the unbalanced output is high enough to feed into a line input on a mixer.

Assuming a digital mixer (that must have a decent channel count in order to accommodate sufficient mic and trigger inputs), then I’d assume it would use the mixer’s standard gate module.

[shufflebeat]

The problem with gated drums in a live scenario is drummers. They insist on playing with a nuanced and musically pleasing flow which is difficult to pin down consistently.

If I set the “closed” state to silent (extreme) and the drummer hits the head gently then I lose the whole hit because s/he didn’t exceed the background noise level (which I used to set the threshold) enough to open the gate. If I have a trigger which is deaf to the b/g noise then I can set my threshold super low and catch all the taps.

Also, I want to catch the initial transient which is so much a part of the drum sound. If the mic itself is opening the gate then I have to wait for:

The mic to react to the sound wave
The mic level to exceed the stage noise level
The A/D conversion process
The input level to exceed the threshold
The gate to react.

Now, all this happens in micro-moments but they do add up and often by the time the gate flips open we end up with a “click” which is effectively the sound of the gate rather than the sound of the drum. We can ameliorate the click effect by slowing down the attack of the opening but we definitely lose some of the initial transient in the process - sometimes that’s a good thing but not often.

If we have a trigger that can send a clean and distinct message to the gate to be open by the time the drum sound gets there then we avoid having to make that compromise.

[James Perrett]

If we have a trigger that can send a clean and distinct message to the gate to be open by the time the drum sound gets there then we avoid having to make that compromise.

It would be interesting to work out how much sooner the trigger signal arrives compared to the mic signal. I would guess that a close mic is probably around 50mm away from the drum - which is the equivalent of an 0.15mS delay. The Drawmer DS201 has an attack time of 10uS at its fastest setting while a digital desk running at 48kHz would have the fastest attack time of around 20uS (though filtering would increase this somewhat). So, as it is very roughly 10X the attack time of the gate, this delay would allow the gate to be virtually fully open by the time the mic reacts to the sound.

[Wease]

I think this is why the triggers were used….a much quicker and therefore cleaner opening of the gate….the engineer did say that he wanted to capture the whole dynamic range of the drums, so I imagine the trigger “activate” settings were very low….he also said there was a quite slow release on the gate.

He was using a Midas digital desk…so their gates could have been the ones used?. I was wandering how physically things would be connected, but didn’t have the chance to take a detailed peak at the systems….(cause I was k8nda playing drums )

It was interesting….quite clever idea really…

[The Elf]

The fundamental problem with gates has always been in achieving reliable results. There's no magic wand, but hysterisis options can help, as can setting a range to allow at least a basic minimum of non-triggering notes ('ghost' notes, ruffs and maybe rim clicks) to get through.

If you've got a consistent drummer on the other end of the triggers you'll probably get away with it in the main, but personally I'd be wary.

[Drew Stephenson]

The problem with gated drums in a live scenario is drummers. They insist on playing with a nuanced and musically pleasing flow which is difficult to pin down consistently.

Are these "drummers" in the room with us now?

[shufflebeat]

The problem with gated drums in a live scenario is drummers. They insist on playing with a nuanced and musically pleasing flow which is difficult to pin down consistently.

Are these "drummers" in the room with us now?

I have heard them spoken of and I think I heard one soundcheck once, but that might have been the keyboard player filling in.

[shufflebeat]

I suspect there may also be some cross-talk between the use of piezo sensors as “regular” pickups and as MIDI triggers. My experience doesn’t extend to this but my curiosity does.

https://www.soundonsound.com/techniques ... c-drum-kit

I do miss Maplins.

[ManFromGlass]

Drew! These drummer unicorns do exist!

I’ve wired up piezos in the past (so simple even I could do it) and put them on all kinds of things that can be struck. I had a Roland midi brain for awhile and I think, but can’t recall for sure, that I plugged one or two triggers into my roland e-drum kit. They worked great for providing the signal the Roland was looking for.

Does a piezo output enough to trigger a gate? That I don’t know.

[Drew Stephenson]

I sometimes forget the more rarefied circles that members of this forum operate in!

[shufflebeat]

.

Does a piezo output enough to trigger a gate? That I don’t know.

I had reason to destroy a “stomp box” pedal a little while ago and was (not) surprised to find a piezo element attached to the underside of a wooden plate in a box - for about £50. The output included a few soldered bits but it was essentially straight out into a DI box.

It sounded fine - til it stopped. I replaced the element with something I had lying around and the owner was perfectly happy.

The signal was at a sensible level at the desk input and could be coaxed into sounding at least as good as a bad kick drum, and better than many, but was more inconsistent as the user had gtr/Vox to think about at the same time.

[shufflebeat]

There's no magic wand, but hysterisis options can help…

Non-hysterical drummers need not apply.

I understand hysteresis to be the comtrol of the difference between the opening and closing thresholds but this doesn’t really appear on the desks I tend to twiddle at. I’ve experimented in Reaper but not really had much satisfaction. If you have time and inclination a brief explanation would be appreciated.

[Drew Stephenson]

I think the glossary link could probably do with a bit of an update too: https://www.soundonsound.com/glossary/hysteresis
I think I've only ever really seen it referred to with gates (and maybe compressors?)

[The Elf]

Essentially hysterisis, in the context of a noise gate, is a margin of difference between the threshold at which the gate opens and the threshold at which it closes.

Having a closure threshold lower than the open threshold can help to preserve, say, the decay of a snare.

The Glossary seems to suggest that a delay is maybe at work to create this behaviour. I'll bow to that description, if that's the case, but the result is the same.

[shufflebeat]

I’ve played with this in the SSL drum strip in Reaper and Reagate but usually on live recordings where b/g noise is significant and consistent and it makes minimal, if any, improvement.

I was a bit worried I might be missing something fundamental but maybe not.

[Wonks]

Essentially hysterisis, in the context of a noise gate, is a margin of difference between the threshold at which the gate opens and the threshold at which it closes.

Having a closure threshold lower than the open threshold can help to preserve, say, the decay of a snare.

The Glossary seems to suggest that a delay is maybe at work to create this behaviour. I'll bow to that description, if that's the case, but the result is the same.

You’ve normally got a ‘minimum gate open time’ parameter, which you could look at as a ‘delay’. Only after that period will the gate look at the signal and start to close if the signal drops below that threshold. So the ‘delay’ is purely a delay before the gate can think about closing.

[shufflebeat]

That sounds suspiciously like.a “hold” feature.

[Wonks]

It is what it is, even if people refer to it with different names.

It does nothing to the level of the signal going through, but it does allow the full drum hit sound to come through unaffected. Especially if you have a loud hit followed by a quiet hit.

It's also very useful for cutting off the end of tom hits, where the pitch rises as the skin tension decreases (after the initial hit increases the tension). It's what toms do, but if not covered by other sounds, then it can sound a bit odd (at least to me).