Tag Archives: Backline

Regarding Electronic Drums

Electronic drums can be great, if you take the time to make them great.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

A question I was asked recently was about electronic instruments – “E Drums” in particular. The query was about how to do them well in a live setup. I’ve worked with bands that make use of electronic percussion, sometimes as an add-on, and sometimes as a core instrument. In either situation, there are a number of particulars that come together to make the sonics an effective part of the ensemble, and a workable element in the sound reinforcement equation.

Tell The Sound People What’s Coming

As usual, homework and communication are key. I’ve always had decent experiences with electronic drums/ sample pads/ whatever when everybody did their advance work: People told me what was coming, how many inputs were needed, what kinds of sounds to look out for, and brought both working gear AND a working knowledge of that gear to the gig. More difficult situations have arisen when musicians have surprised me with extra needs: “Well, yeah, we need two lines for the trigger pads, but we’ve also got this other unit that needs two more DIs, so…” Particularly a multi-band or full-on festival situation, information about those additional inputs would have been really good to have before we were setting up. It’s also tough when a piece of equipment has chronic problems, but it’s brought along to a mission-critical situation anyway in hopes that “It’ll hold together.” (Often, it doesn’t hold together and we waste time scrambling. Or it fails at a critical moment and really embarrasses you.)

Carefully Integrate Your Proportions

I know I say this a lot, but I’m going to say it again. If it sounded right in rehearsal, it has a fighting chance of sounding right at the show. If not – who knows?

Especially when it comes to blending triggered sounds with acoustic drums, getting the balance correct during practice is crucial. Even more crucial is being sure that the balance can be recreated live. An important example is found in the case of bands that want to blend an earth-shattering synth kick with loud, traditional drums. That’s a very difficult thing to do, unless you have a truly enormous PA system available. Anybody who has heard real drums in a real room knows that they can make as much noise as an entire small-venue PA rig, given a little effort on the part of the drummer. Drowning that special accent in a tidal wave of other racket is very easy. The folks who learn to play so that the accent has the room to actually do something are the successful ones. The people who expect a normal-sized audio system to somehow make 130+ dB at 35 Hz are the disappointed ones.

Corollary: If you want your electronic drums to sound massive, you need to figure out how “big” they can reasonably be, and make everything else significantly “smaller” than that. Meditate upon this.

If It Won’t Work Without [x], Bring [x]

You should always be able to be fully self-contained with electronic percussion. That is, if a certain amount and character of sound is absolutely necessary for your e-drums to work out, you need to have the option of providing that support yourself. This is another important reason to carefully advance the show; If you don’t, you may get a nasty surprise when the provided PA can’t do the job.

If The Blend Is Mission-Critical, Do It Yourself

With e-drums, I do like to be able to get separate outputs for kick, snare, a submix of toms, and a submix of cymbals/ FX/ and other percussion sounds. Just like with regular drums, its handy to be able to make some decisions about what’s right for the room. At the same time, I’m 100% onboard with getting a premix of everything, especially if you need a very specific balance. In the case of a lot of diverse sounds, where they don’t necessarily come together to function as one large instrument, it’s far better for you to build your own mix and hand it off to me. With a complicated blend, it doesn’t make sense to input a ton of lines and then struggle to put it all back together.

None of this information is really world-changing, but that’s the reality: There’s no shortcut, and no mystical knob of mix perfecting. Good communication and “gettin’ it right at home” are what pay the dividends.


The Number The Knob’s Pointing Toward Doesn’t Matter

A “Schwilly” article on how too loud is too loud, no matter what number the amp is set to.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

“If the amplifier doesn’t sound good until most people think it’s too loud to sound good, then the amplifier doesn’t actually sound good.”


Read the whole thing here!


Actually, Your Equipment Is Probably Fine

Working as a team is more important than most anything.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

This is from another article that I wrote for Schwilly Family Musicians: “What they had failed to do was to play as a team, and that made their perfectly adequate gear SEEM like a problem area.”

Read the whole thing for free, here.


Case Study: Creating A Virtual Guitar Rig In An Emergency

Distortion + filtering = something that can pass as a guitar amplifier in an emergency.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

The Video

The Script

Imagine the scene: You’re setting up a band that has exactly one player with an electric guitar. They get to the gig, and suddenly discover a problem: The power supply for their setup has been left at home. Nobody has a spare, because it’s a specialized power supply – and nobody else plays an electric guitar anyway. The musician in question has no way to get a guitar sound without their rig.

At all.

As in, what they have that you can work with is a guitar and a cable. That’s it.

So, what do you do?

Well, in the worst-case scenario, you just find a direct box, run the guitar completely dry, and limp through it all as best you can.

But that’s not your only option. If you’re willing to get a little creative, you can do better than just having everybody grit their teeth and suffer. To get creative, you need to be able to take their guitar rig apart and put it back together again.

Metaphorically, I mean. You can put the screwdriver away.

What I’m getting at is this question: If you break the guitar rig into signal-processing blocks, what does each block do?

When it comes right down to it, a super-simple guitar amp amounts to three things: Some amount of distortion (including no distortion at all), tone controls, and an output filter stack.
The first two parts might make sense, but what’s that third bit?

The output filtering is either an actual loudspeaker, or something that simulates a loudspeaker for a direct feed. If you remove a speaker’s conversion of electricity to sound pressure waves, what’s left over is essentially a non-adjustable equalizer. Take a look at this frequency-response plot for a 12″ guitar speaker by Eminence: It’s basically a 100 Hz to 5 kHz bandpass filter with some extra bumps and dips.

It’s a fair point to note that different guitar amps and amp sims may have these different blocks happening in different orders. Some might forget about the tone-control block entirely. Some might have additional processing available.

Now then.

The first thing to do is to find an active DI, if you can. Active DI boxes have very high input impedances, which (in short) means that just about any guitar pickup will drive that input without a problem.

Next, if you’re as lucky as I am, you have at your disposal a digital console with a guitar-amp simulation effect. The simulator puts all the processing I talked about into a handy package that gets inserted into a channel.

What if you’re not so lucky, though?

The first component is distortion. If you can’t get distortion that’s basically agreeable, you should skip it entirely. If you must generate your own clipping, your best bet is to find some analog device that you can drive hard. Overloading a digital device almost always sounds terrible, unless that digital device is meant to simulate some other type of circuit.
For instance, if you can dig up an analog mini-mixer, you can drive the snot out of both the input and output sides to get a good bit of crunch. (You can also use far less gain on either or both ends, if you prefer.)

Of course, the result of that sounds pretty terrible. The distortion products are unfiltered, so there’s a huge amount of information up in the high reaches of the audible spectrum. To fix that, let’s put some guitar-speaker-esque filtering across the whole business. A high and low-pass filter, plus a parametric boost in the high mids will help us recreate what a 12″ driver might do.
Now that we’ve done that, we can add another parametric filter to act as our tone control.

And there we go! It may not be the greatest guitar sound ever created, but this is an emergency and it’s better than nothing.

There is one more wrinkle, though, and that’s monitoring. Under normal circumstances, our personal monitoring network gets its signals just after each channel’s head amp. Usually that’s great, because nothing I do with a channel that’s post the mic pre ends up directly affecting the monitors. In this case, however, it was important for me to switch the “monitor pick point” on the guitar channel to a spot that was post all my channel processing – but still pre-fader.

In your case, this may not be a problem at all.

But what if it is, and you don’t have very much flexibility in picking where your monitor sends come from?

If you’re in a real bind, you could switch the monitor send on the guitar channel to be post-fader. Set the fader at a point you can live with, and then assign the channel output to an otherwise unused subgroup. Put the subgroup through the main mix, and use the subgroup fader as your main-mix level control for the guitar. You’ll still be able to tweak the level of the guitar in the mix, but the monitor mixes won’t be directly affected if you do.


Bring ‘Em If Ya Got ‘Em

It’s a Schwilly guest-post!

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

“If you have some sort of device that you can use to tweak the sound of your instrument, even if that’s just a bit of extra volume, you should definitely have that handy.”


Want to know why? Read the whole thing here, for free.


Pre Or Post EQ?

Stop agonizing and just go with post to start.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

Want to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

Oh, the hand-wringing.

Should the audio-human take the pre-EQ split from the amplifier, or the post-EQ split? Isn’t there more control if we choose pre-EQ? If we choose incorrectly, will we ruin the show? HELP!

Actually, I shouldn’t be so dismissive. Shows are important to people – very important, actually – and so taking some time to chew on the many and various decisions involved is a sign of respect and maturity. If you’re actually stopping to think about this, “good on ya.”

What I will not stop rolling my eyes at, though, are live-sound techs who get their underwear mis-configured over not getting a pre-EQ feed from the bass/ keys/ guitar/ whatever. Folks, let’s take a breath. Getting a post-EQ signal is generally unlikely to sink any metaphorical ship, sailboat, or inflatable canoe that we happen to be paddling. In fact, I would say that we should tend to PREFER a post-EQ direct line. Really.


First of all, if this terminology sounds mysterious, it really isn’t. You almost certainly know that “pre” means “before” and “post” means “after.” If you’re deducing, then, that setting a line-out to “pre-EQ” gets you a signal from before the EQ happens, then you’re right. You’re also right in thinking that post-EQ splits happen after all the EQ tweaking has been applied to the signal.

And I think we should generally be comfortable with, and even gravitate toward getting our feed to the console from a point which has the EQ applied.

1) It’s consistent with lots of other things we do. Have you ever mic’ed a guitar amp? A drum? A vocalist? Of course you have. In all of those cases (and many others), you are effectively getting a post-EQ signal. Whether the tone controls are electronic, related to tuning, or just part of how someone sings, you are still subject to how those tonal choices are playing out. So, why are you willing to cut people the slack to make choices that affect your signal when it’s a mic that’s involved, but not a direct line?

2) There’s no reason to be afraid of letting people dial up an overall sound that they want. In fact, if it makes it easier on you, the audio-human, why would that be a bad thing? I’ve been in situations where a player was trying desperately to get their monitor mix to sound right, but was having to fight with an unfamiliar set of tone controls (a parametric EQ) through an engineer. It very well might have gone much faster to just have given the musician a good amount of level through their send, and then let them turn their own rig’s knobs until they felt happy. You can do that with a post-EQ line.

3) Along the same track, what if the player changes their EQ from song to song? What if there are FX going in and out that appear at the post-EQ split, but not from the pre-EQ option? Why throw all that work out the window, just to have “more control” at the console? That sounds like a huge waste of time and effort to me.

4) In any venue of even somewhat reasonable size, having pre-EQ control over the sound from an amplifier doesn’t mean as much as you think it might. If the player does call up a completely horrific, pants-wettingly terrible tone, the chances are that the amplifier is going to be making a LOT of that odious racket anyway. If the music is even somewhat loud, using your sweetly-tweaked, pre-EQ signal to blast over the caterwauling will just be overwhelming to the audience.

Ladies and gents, as I say over and over, we don’t have to fix everything – especially not by default. If we have the option, let’s trust the musicians and go post-EQ as our first attempt. If things turn out badly, toggling the switch takes seconds. (And even taking the other option might not be enough to fix things, so take some deep breaths.) If things go well, we get to ride the momentum of what the players are doing instead of swimming upstream. I say that’s a win.


Percussive Maintenance

If you want your drums to sound “like that,” they should already pretty much sound “like that.”

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

percussive-maintenanceWant to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

“Especially without a huge PA, unlimited audience volume tolerance, and an anechoic chamber, totally remaking the sound of a real kit in a real room is a truly difficult proposition.”


Read the whole thing, free, at Schwilly Family Musicians.


Why Chaining Distortion Doesn’t Sound So Great

More dirt is not necessarily cool dirt.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

ampsWant to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

One day, just before Fats closed, I was talking with Christian from Blue Zen. We were discussing the pursuit of tone, and a discovery that Christian had made (with the help of Gary at Guitar Czar). Christian had been trying to get more drive from his amp, which already had a fair bit of crunch happening. So, he had put a distortion pedal between the guitar and the amplifier input.

He hadn’t liked the results. He found the sound to be too scratchy and thin.

Upon consultation with Gary, the distortion pedal had been removed, and a much cleaner boost substituted. Christian was definitely happier.

But why hadn’t the original solution worked?

The Frequency Domain

Distortion can be something of a complex creature, but it does have a “simple” form. The simple form is harmonic distortion. Harmonic distortion occurs when the transfer function of an audio chain becomes nonlinear, and a tone is passed with additional products that follow a mathematical pattern: For a given frequency in a signal, the generated products are integer multiples of that frequency.

Integers are “whole” numbers, so, for a 200 Hz tone undergoing harmonic distortion, additional tones are generated at 200 Hz X 2, 3, 4, 5, 6, etc. Different circuits generate the additional tones at different intensities, and which pattern you prefer is a matter of taste.

For example, here’s an RTA trace of a 200 Hz tone being run through a saturation plugin.

pure-tone-distortion

(The odd-numbered harmonics are definitely favored by this particular saturation processor’s virtual circuit.)

The thing is that harmonics are always higher in frequency than the fundamental. The “hotter” the harmonic content, the more the signal’s overall frequency response “tilts” toward the high end. As distortion piles up, the overall timbre of a signal can start to overwhelm the lower-frequency information, resulting in a sound that is no longer “warm,” “thick,” “fat,” “chunky,” “creamy,” or whatever adjective you like to use.

Take a look at this transfer function trace comparing a signal run through one distortion stage and two distortion stages. The top end is very pronounced, with plenty of energy that’s not much more than “fizz” or “hiss”:

transfer-function-dualdistortion

If you chain distortion into distortion, you’re quite likely to just pile up more and more harmonic content, thus emphasizing the high end more than you’d prefer. There’s more to it than that, though. Look at this RTA trace of a tone being run through chained saturation plugins:

pure-tone-doubledistortion

To make things easier to see, you can also take a look at this overlay of the two traces:

pure-tone-overlay

There’s noticeably more energy in the high-end, and the distortion products are also present at many more frequencies. The original harmonic distortion tones are being distorted themselves, and there may also be some intermodulation distortion occurring. Intermodulation distortion is also a nonlinearity in a system’s transfer function, but the additional tones aren’t multiples of the original tones. Rather, they are sums and differences.

IM distortion is generally thought to sound pretty ugly when compared to harmonic distortion.

So, yes, chaining distortion does give you more drive, but it can also give you way more “dirt” than you actually want. If you like the sound of your amp’s crunch, and want more of it, you’re better off finding a way to run your clean signal at a higher (but still clean) level. As the amp saturates, the distortion products will go up – but at least it will be only one set of distortion products.

Dynamic Range

The other problem with heaping distortion on top of distortion is that of emphasizing all kinds of noises that you’d prefer not to. Distortion is, for all intents and purposes, a “dirty” limiter. Limiting, being an extreme form of compression, reduces dynamic range (the difference between high and low amplitude signals). This can be very handy up to a point. Being able to crank up quieter sounds means that tricks like high-speed runs and pinch-harmonics are easier to pull off effectively.

There’s a point, though, where sounds that you’d prefer to de-emphasize are smashed right up into the things you do want to hear. To use a metaphor, the problem with holding the ceiling steady and raising the floor is that you eventually get that nasty old carpet in your face. The noise of your pickups and instrument processors? Loud. Your picking? Loud. Your finger movement on the strings? Loud. Any other sloppiness? Loud.

Running distortion into distortion is a very effective way to make what you’d prefer to be quiet into a screaming vortex of noise.

Is Chaining Distortion Wrong?

I want to close with this point.

Chaining distortion is not “wrong.” You shouldn’t be scared to try it as a science experiment, or to get a wild effect.

The point of all this is merely to say that serial distortion is not the best practice for a certain, common application – the application of merely running a given circuit at a higher level. For that particular result, which is quite commonly desired, you will be far better served by feeding the circuit with more “clean” gain. In all likelihood, your control over your sound will be more fine-grained, and also more predictable overall.


Buzzkill

Ridding yourself of hum and buzz is like all other troubleshooting: You have to isolate the problem to fix it.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

buzzkillWant to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

Not all hums and buzzes are equally bad. Honeybees hum and buzz, but they’re super-helpful creatures that are generally interested in being left alone and making honey. Wasps, like the one pictured above, are aggressive jerks.

Of course, this site isn’t about insects. It’s about audio, where hum and buzz mean problems. Unwanted noise. Blech.

I recently got an email from a friend who wanted to know how to de-buzzify (I just made that word up) a powered mixer. When you mercilessly distill what I told him, you come up with a basic truth that covers all of troubleshooting:

The probability of an effective fix for a problem is directly proportional to your ability to isolate the problem.

Solitude

The importance of finding the exact location of a fault is something that I don’t believe I can overemphasize. It’s the key to all the problem-solving I’ve ever had to do. It doesn’t matter if the problem is related to audio signal flow, car trouble, or computer programming; if you can actually nail down the location of the problem, you’ve got a real shot at an effective (and elegant) fix.

The reverse is also true. The less able you are to pinpoint your conundrum’s place of residence, the more likely you are to end up doing surgery with a sledgehammer. If you can’t zero-in on a root cause, you end up “fixing” a certain amount of things that aren’t actually being troublesome. The good news is that you can usually take an iterative approach. All problems begin with “this system isn’t working as I expected,” which is a completely non-specific view – but they don’t have to end there. The key is to progressively determine whether each interrelated part of the system is contributing to the issue or not. There are lots of ways to do this, but all the possible methods are essentially an expression of one question:

“Is the output of this part of the system what I expect it to be?”

So…here’s a way to apply this to buzz and hum problems.

Desperately Seeking Silence

Talking in depth about the exact electrical whys and wherefores surrounding strange and unwanted noises is a little bit beyond my experience. At a general level, though, the terminology of “ground loop” provides a major clue. Voltage that should be taking a direct path to ground is instead taking a “looping” or “circuitous” path. A common cause of this is equipment receiving mains (“wall”) power from two different circuits, where each path to mains ground has a significantly different impedance. There is now a voltage potential between the two pieces of gear.

Bzzzzzzzz….

You can also have a situation where two device’s audio grounds are interconnected such that there is a potential between the two devices.

Hmmmmmmzzzzzzzz…

Anyway.

The first thing to do is to decide what piece of equipment you’re testing against. Maybe it’s a mixing console. Maybe it’s an amplifier. Whatever it is, you are asking the question from before:

“Is the output of this part of the system what I expect it to be?”

Or, more specifically…

“I expect this device’s output to be quiet, unless an audio signal is present. Is that the case?”

To answer that question, you need isolation.


WARNING: At NO point should you do anything to disconnect the mains-power/ safety grounds from your equipment. It’s there to prevent you from dying if the equipment chassis should become energized. In fact, as a start, try to verify that the mains-power sockets you are using actually DO provide a connection to “earth.” If they don’t, stop using them until they’re fixed. You may even find that your noise problem goes away.


To get isolation, start by disconnecting as much as you possibly can from the DUT (the Device Under Test). Of course, you’ve got to have some kind of way to monitor the output, so that might mean that you can’t disconnect everything. As much as possible, try to ensure that all mains-power grounds offer the same impedance – if it must stay connected, and it requires mains power, get all the power to connect to the same socket. A multi-outlet power tap can come in handy for this.

Is the output what you expect?

If yes, then something which was connected to your DUT’s input has a good chance of being the problem. At this point, if possible, treat each potential culprit as a secondary DUT in turn. If feasible, connect each suspect directly to your monitoring solution. If the ground loop manifests itself, and the suspect device requires mains power, try getting power from the same tap that the primary DUT is on. If the loop goes away, you’ve established that the two devices in play were likely having an “unequal impedance to ground” problem. If the loop stays in effect, you can jump back up to the beginning of this process and try again, but with the gear you had just plugged in as the new, primary DUT. You can keep doing this, “moving up the stack” of things to test until you finally isolate the piece of gear that’s being evil. (IMPORTANT: Any piece of the chain could be your problem source. This includes cables. You may need to pack a lunch if you have a lot of potential loop-causers to go through.)

If you can’t get the buzz to manifest when adding things back one at a time, then you might have a multi-device interaction. If possible, work through every possible combination of input connections until you get your noise to happen.

But what if the output on the original DUT was NOT what you expected, even with everything pulled off the output side?

At that point, you know that an input device isn’t the source of your trouble with this particular DUT. This is good – your problem is becoming isolated to a smaller and smaller pool of possibilities.

Try to find an alternate way to connect to your monitoring solution, like a different cable. If the problem goes away, that locates the cable as the menace. If you’re switching the connection, and the noise remains with no audio path, then the monitoring system has the problem and you need to restart with a new DUT. (If you’ve got a mixer connected to an amp and a speaker, and a ground loop stays audible when the mixer-to-amp connection is broken, then the amp is your noise source.)

If you’ve tried all that and you still have the buzz, it’s time to try a different circuit. Get as far away from the original mains-power socket as you can, and reproduce the minimal setup. If the ground-loop goes away, then you may have a site-wiring issue that’s local to the original socket(s). If the problem doesn’t go away, it’s time to take a field-trip to another building. It’s possible to have a site-wide electrical problem.

If the loop still won’t resolve, it’s very likely that your DUT has an internal fault that needs attention. Whether that means repair or replace is an exercise left to the reader.

Hopefully, you don’t get to that point – but you won’t figure out if you ARE at that point unless you can isolate your problem.


How To Spend A Ton Of Money

Really loading up your credit cards is easily done. Just keep trying to solve problems by modifying variables unrelated to those problems.

Please Remember:

The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

differentmicpresWant to use this image for something else? Great! Click it for the link to a high-res or resolution-independent version.

The room was an acoustically hostile firestorm of reflections and standing waves.

The band’s backline was barely functional.

The guitar amps had all the midrange dialed out.

A really expensive console with different mic pres would have TOTALLY fixed all that.

Right?