Shop Talk & Pro Audio Insights

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Namaste, Dear Music Lover,

Let’s “talk shop” for a while, okay? This post is about some of the audio gear we singers use, and how to best use it. As usual, all ‘gear talk’ here is geared mainly to playback singers (and any who aspire to sing for India’s Bollywood movie industry). Yes, I do put in the odd pun from time to time.

Tours can be exciting!

Microphones, Mixers

While in studio, there is usually whatever type of mic the music director believes will best capture our vocals. In live performances, we may have to either bring one of our own trusty vocal mics, or be stuck with one that is not ideal. Often that [meaning we’re all using some venue-provided audio gear] means we’re faced with not the best-quality gear.

Let’s not become snobbish and demand something that is not available to the event/venue management, when they usually only have what they have (or in some cases, they rented audio gear pre-abused [as rental gear of dubiously, possibly absurdly-long life]).

If you want to gain a keen appreciation for what pro audio folks do, including toting all of that sensitive equipment around, carefully setting it all up, testing and dialing in its best settings… try working on audio crews for a few gigs.

It may all seem too easy, but it’s NOT so simple. We promise you that! Please note that while we may drop in links of various commercial products, we DO NOT ENDORSE them by merely adding them here. The links are strictly intended as educational resources. Anyway, back to our discussion about using mics…

Fortunately, very few mics require maintenance beyond battery replacement (if they even use batteries). It’s also good that mics don’t need tuning or other skilled maintenance. Most mics just capture sounds and convert them to audio signals. We plug them in and turn them on (if there’s a switch) and voilà! Vocals in the mix!!

I sing, I blog, I paint, etc.

So where am I going with a full post on the topic of audio gear? Playback singing begins in a recording studio (usually one well-equipped for movie post-production work), but we singers are often blessed to be asked to perform our film songs live as well. In such situations, audiences expect to hear us doing our vocals without issues like mic feedback or muffled audio!

If you’re new to the business of live music performance, I can tell you that such knowledge is best learned over years, not hours or minutes. We can all be more informed about which gear will best suit our needs and help to bring our sounds forward in live situations. For our tech types, audiophile gear and systems can be a lifelong pursuit. But for most singers like me, the fascination ends at utility (if it works well, great; if it doesn’t, you may hear me cry, “Help!?!”—but only in Sound Check).

It is a simple fact of professional music that we are expected to deal with and make best use of whatever mic and venue/tour audio gear that we’re given (again, unless we have our own, and we know how to use it in various venues, interfacing with any of several other types and qualities of audio equipment like a recording studio mixing desk or live sound-reinforcement board)—so, often in more advanced setups within a complex (or basic) wireless system… it’s best to… leave all such matters to others who specialize in them.

The wireless aspects aren’t especially unique or pertinent to singers. Nevertheless, we’ll look into a few possible considerations on that front (later). Whereas actors are expected to simply [okay, it’s not easy to] lip sync along with pre-recorded vocals; we singers need to hold forth with full artistry at each concert.

Making music at a live venue [showing afflatus commensurate with our best takes already on the official movie soundtrack] requires quite a team effort, that to be pulled off without issue also means the audio system must be ready to perform flawlessly, too [or issues may arise]. So in this post, let’s first discuss the mic itself (with its pickup or diaphragm capsule and other parts) and its role for singers; we’ll examine other relevant gear and audio factors in our future Shop Talk posts.

The microphone or mic is simply an audio tool for converting sound into signals that provide our sounds to other electronics, in order to convey or amplify our instrument [voice] for either recording or audio reinforcement. It’s really nothing else (except the aforementioned wireless mic also has some built-in purpose driven radio circuitry that enables it to be used without a cable, allowing singers to move around without jumping or stumbling over cables or other on-stage items).

While audio electronics is generally not an area in which artists are expected to be experts, it can only help singers to have at least a firm grasp of some fundamental ideas and options that apply to all or most mics, mixers, amplifiers and loudspeakers.

So here I am sharing what I’ve learned over the years (as expanded by my sharp web team). If this talk all begins to sound like a boring lecture that could only interest the techy types, I think if you hear (read) us out in this post, you’ll be better prepared to have good performances not flawed by the issues less-knowledgeable others may experience.

“Education is worth its weight in gold. Make no mistake about it.” —Clyde Drexler, Athlete

“Education is not preparation for life; it is life itself.” —John Denver, Singer-Songwriter

Singer-extraordinaire Sonu ji Nigaam in concert

So please, let’s never argue over whether people who care about fine arts should or shouldn’t be best informed about all aspects of them! I’ll try to confine the scope of my Shop-Talk posts to the most practical aspects for everyday use.

Maybe I treasure the few facts and techniques I’ve learned because I’ve been blessed to have learned so much of the info. and skills from great talents like Pritam da and his studio engineers and audio technicians. Though I did have a little bit of training before I was invited to Mumbai, so not all of this was new to me by age 18 (when I arrived to the set of Indian Idol as the youngest contestant).

My father and some of his musical friends had shown me the ropes to some extent. (More like Baba et al. showed me the mic cables and how to unwind and plug them in, and how to avoid stumbling over audio gear on stage, lol.) Also at the end of a show, I saw how to carefully unplug and wind up the cords for storage until the next occasion. Those parts really aren’t difficult. While as noted, we’ll get into the topic of wireless systems later; let’s discuss wired gear first, in order to explain basic pro audio and so help you consistently perform as musically as possible through various live sound systems.

But first, one very important caveat, and I’m telling you at the outset, Dear Music Lover: as part of this job, Sound Checks are required. While in some cases, established singers have “advance staff” who prepare all of their equipment prior to the “name artist(s)” arriving at the venue (especially in tour situations), most pro-music talent schleps their own audio gear and sets it up, plugs it in or wirelessly connects to the mixer, and tests it themselves. Have you never schlepped? If not, you’ve missed out, lol. It can give you real appreciation for the detailed work done by others to support shows or live musical acts in concerts.

Seeing so many music performances where the lacking/aging audio technology negatively impacted the performance, I thought my prayers had been answered by the onset of wireless mics as far more common. But there are so many other factors involved in live music production… it seems that I’ll have plenty of additional Shop-Talk material for several other posts to share in months and years ahead.

Now a fairly-brief primer on mics (yes, prior to this edit, it did run somewhat longer):

Its pickup pattern is one part of a mic’s technical aspects that is especially important. While various patterns are available, only two basic patterns exist: omnidirectional and unidirectional (the latter type is also simply called directional). To simplify this talk, some mics pick up sounds equally-loudly from any direction (omnidirectional, meaning lit. from all directions), while other mics have some type of pattern wherein from one direction sounds are well picked-up, but from another, they’re not as well picked-up.

For nearly obvious reasons, singers most often use directional mics (that we point directly or indirectly at our mouths). The reason this seems obvious to us is if we have ever used an omnidirectional mic for live vocals, we may well have had the frightening experience of hearing that dreadful feedback squeal. If we delve much deeper, this discussion can get very technical, so that’s about deep-enough for now! You’ll also find more in-depth tutelage on mic pickup patterns linked at the bottom of a paragraph quite a bit farther down in this post. Briefly, the most-common pattern is called cardioid [CARD-y-oid], because its pickup field is heart [cardio] shaped.

What is feedback? Isn’t that simply consumer opinions offered to providers? Lol, well, if audiences are the music’s consumers and we singers are its providers, I must be quite clear on this point: if there’s one thing music consumers hate, it’s having their ears insulted or abused by the awful sound of an audio setup giving a super-loud whistling sound (because some less-skilled person put a mic too near a speaker while it was turned up loudly). When such things happen at a live show or recording situation, the “guilty” party is often noted as among the least-experienced or least-skilled participants. Or worse! Don’t let that person-being-pointed-at be you! Just don’t abuse your mics, and you’ll be fine.

First pro tip on mics: unless you were testing it out in a sound check and have full confidence, never cup your hands around a mic to try to make it (really, to make your voice sound) louder. Why? Because that’s one of the surest ways to produce uncontrolled audio feedback. It’s often also a mark of an amateur or less-skilled artist. If your mic needs to be louder, just ask the sound tech to raise the mic gain [or back off the mic-input trim] until the setting is usable. After you gain [yes, now oddly a pun here] some stage performance experience, you’ll learn the few key hand signals to make that happen. Here’s how it’s done seamlessly by seasoned artists:

  1. Look directly at the sound engineer (and smile, if applicable to get their attention).
  2. Make sure they see you (and your hands).
  3. Gesture at (or point to) your mic. (Or if you’re confident it’s about your monitors, point at them to the monitors engineer.)
  4. Make the “lift-it-up” gentle hand gesture. If they’re good, they’ll nudge its volume up gradually as you continue singing—until you nod (indicating “that’s enough”. If the mic is so ‘hot’ it could go into feedback, gesture down). To some, thumbs-up means stop! “Lift-it-up” and “Put-it-down” apply to mixer faders. (At some point, every musician must learn to think like an orchestra conductor! By the way, “thumbs-down” looks tacky on stage (is not recommended). Conductor-style hand gestures are always best-practices.)
  5. With a little practice and luck, this all occurs virtually unnoticed by the audience (because you and your sound crew are on the same page after a time or two).
  6. Unless you’re currently in a sound check, refrain from talking about technical issues over the sound system. (So distracting!) Furthermore, shrugging one’s shoulders to indicate one cannot hear monitors just looks clueless (and conveys nothing else).

Finally on this tip: there are typically two sound engineers in a larger venue. Be clear (before signaling) whether you want your mic louder for a) being able to hear yourself (the Monitor Mix) or b) your vocal mix in the main speakers (aka the FOH* Mix). If you can’t hear yourself, it’s very possible that others can’t hear you, either. But from your location on stage, you can’t possibly know how it all sounds from the audience’s perspective. So please, be patient—live music is a team activity! If one engineer needs to confer with the other to get it all right, so be it. *FOH=Front of House [theatre].

Dear Music Lover, one should ensure that one’s monitors are correctly set up during the Sound Check. So typically, if there’s an issue in the show, we’re more likely to be asking for ‘more juice’ from the FOH/main system engineer. It’s also good general knowledge to refrain from blaming the sound people for how you perform when your singing is not at its best. (Still, some less-professional talents tend to take a low road and blame others.)

Before we continue to detail a few more aspects of audio and its dos and don’ts, I want to briefly discuss monitors. There are two basic monitor types: on-stage and self-contained (or worn on-body).

Stage monitors (aka wedges) are usually wedge-shaped or angled-up smallish loudspeaker cabinets positioned near the front of the stage, usually on the floor facing up at the musicians. These are often the speakers that if overdriven (turned up excessively loudly into a feedback situation), cause so much concern to everyone.

Note: Some monitors (or even speakers facing the audience) positioned up on stands could swing to angles that are likely to cause feedback. But in live situations, it’s usually not our job as artists to move heavy gear around. Nor is it up to us to select concert equipment from the many options available on the market.

Feedback during a show makes it obvious that either a) the sound check wasn’t done well, or something in the audio setup has gone awry, b) the singer is not skilled at this type of setup, or c) the person running the sound reinforcement (FOH/main and/or Monitor) system has stopped paying attention or made a mistake, or (in rare situations) the monitors were not positioned well, and perhaps in performing enthusiastically, or if there is a lot of movement on stage, the acoustics have changed (thereby triggering feedback in unpredictable ways).

During complex shows with costume changes, dancers and all manner of staging like pyrotechnics, it’s possible that the acoustics on stage change a lot, too. If you see audio techs scrambling around to swap cables or re-position monitor/main speaker cabinets during the show, it’s best to refrain from drawing any attention to their work, which ideally is transparent to audiences.

All of the reasons why feedback occurs are immaterial to the audience (and equally or more so to the artists, maybe more because they’re so passionate about putting their best sounds out to be heard, but instead an audible affront/assault can spoil the mood—so requisite precautions are in order). One good thing about monitors (no one actually calls them “loudspeakers”) at live shows is they’re usually right in front of us; so, it’s never a good idea to point the front of a microphone directly at them!

Well, we’re only partway into the bulk of what I want to share here, and we’ve hardly begun to discuss this technology, or that part of it that we think could best inform singers. It’s a lot! I realise it can be daunting to grasp in one go, so I’m making this post in sections for easier reading, and I’ve also already digressed. Now back to the other basic class of monitors: self-contained or on-body.

An on-body monitor (typically worn as a form-fitting in-ear unit) is one that is contained fully on the artist’s person. In studio environments, we “talent” typically wear bulky headphones that have thick cushions to isolate our ears from external sounds and to avoid extra sounds like click track or miscellaneous percussion from getting directly into our vocal tracks. Generally, these thick cushions serve to reduce or eliminate the audio phenomenae termed mic bleed and crosstalk.

Bulky isolation headphones aren’t conducive to long periods of wear, e.g. especially on stage (under intense theatrical lighting and while wearing heavy costumes or makeup) or for long rehearsals and recording sessions [where ear infections from overuse are also seriously to be avoided]. This is one argument on behalf of universal-fit (one-size fits most) models designed to fit heads and ears of various sizes. One may, if required be able to wear a looser-fit pair of earbuds or lightweight earphones for hours.

When an artist must manage their full stage costume plus a wireless mic, often a sound person assists with logistics like clipping on the portable radio transmitter/battery pack. But when the spotlights and cameras are trained on us, that’s no time for fidgeting with a wireless gear belt or an intermittent Bluetooth earpiece! The audience expects to be entertained, not trained in audio technology.

The lower cost of one-size gear makes them especially attractive for touring, because should they malfunction or be damaged or destroyed, sourcing timely repairs or replacements is far more feasible. These lower-cost individual monitors are often available in a variety of colours, finishes and styles, too. Some artists are also fitness enthusiasts, so models designed for jogging/cycling or other “hard use” may be best for them. (When I’m off-stage, I’m happy to take all the gear I no longer need off, too.)

Mic bleed occurs when an unwanted sound reaches a mic. Crosstalk occurs when an unwanted adjacent sound gets into another nearby channel (where it’s not meant to be). I’m not discussing stereo (binaural, with L and R channels) mixes in this post. Maybe I’ll get into that in a later post… or not, because that’s often more for recordings (and anyway, solo/lead vocals are seldom mic-ed up in stereo).

But how often might a bulky pair of headphones (often due to their shape they’re called cans by artists) look attractive in a live performance? Not so often, actually. However, you may see them used in Coke Studio [Mumbai] videos (tracked in an actual recording studio). We’ve actually seen some singers looking very cute while sounding very musical wearing headphones in Coke Studio! However singers can do it, hearing ourselves during performances is crucial; it’s simply not optional where excellence is expected.

While we’re defining basic audio jargon and tech, feedback of the problematic type (and there is also a type of desirable feedback that’s used in radio: it’s called regenerative feedback, which increases the sensitivity of AM radio receivers quite a bit, but audio feedback is generally a big problem). Since the 1990s, we’ve had specialized equipment that can dramatically reduce feedback, but such gear isn’t always present at every live venue.

Audio feedback is caused when a mic input is swamped by amplified mic audio output from the loudspeakers. When this feedback occurs, the sound simply builds and builds like a cyclone or tornado in a small area (or in live situations, a room or stage setup) that grows and grows (very quickly to annoying proportions) and oscillates (meaning vibrates at one pitch) or loops uncontrollably. In other words, it just rings or whistles very loudly (because it’s like a dog chasing its tail, and the infinite cycling intensifies the sound). When it occurs, most audio techs cut all audio to make it stop.

We all know the discomforting feeling of hearing feedback at a live show, and it’s not a trivial matter! So how do singers avoid causing feedback with a microphone? The first technique is to refrain from aiming one’s mic at one’s monitor or main (also termed FOH/front-of-house) loudspeakers [yes, I repeated that explanation for those speed reading this].

Another, but far less common issue is with headsets that have a tiny mic capsule on a thin stem mere centimetres away from the earpieces—for obvious reasons (like the mic suddenly becomes bent or rotated to somehow point at either ear driver); one may need to remove the entire headset to reset its alignment! (Usually, such technical difficulties are best handled deftly and at least mostly off-stage.)

We’ve mentioned two basic pickup patterns (omnidirectional meaning every direction is picked-up being one), and in live performances, we singers benefit from mics with more directional pickup patterns (actually with the goal of reducing or eliminating feedback). The most usual type of vocalist mic has what’s termed a cardioid pattern (so named for its resemblance to a heart’s shape). Because the most popular mic for vocals is the trusty Shure Bros. SM58, it’s built with a cardioid pattern capsule that makes it less sensitive from the back. Here’s a primer on mic pickup patterns.

Another pro tip: some mics have an On/Off switch. Be sure if you’re not using it to switch it Off, but be equally sure to switch it back On before you sing into it (if you want to be heard)! (This is also called the Singer’s IQ Test.) What’s really funny to sound engineers is an artist saying their mic isn’t working after it seemed fine in sound check or rehearsal… only to learn that it’s simply been switched off. We can’t blame any sound guys/gals for that mistake, though many spaced-out or overly-excited singers have tried to do so!

Okay, so your mic is all set, and you made sure that you wouldn’t trip over the cable (if it has one). You know whether it’s switched On or Off! If it’s a wireless mic with a battery, your team already made sure it’s got a fresh battery that will last for the entire show. You double-checked and triple tested it all earlier.

Looks familiar?

Now we shift gears a little while we’re on the mic setup topic. The Shure SM58 is also called a Dynamic mic, because it works using principles of a magnetic capsule to capture sounds. In practice, it’s like a tiny loudspeaker with a diaphragm that has a “voice coil” mounted on it. When sounds move the diaphragm, it in turn moves the voice coil attached to it, and because the voice coil is also mounted over a permanent magnet, it literally produces electrical energy that is in turn amplified by a mixer or preamplifier, and then this “audio signal” is either sent to a recording device to transcribe your singing as a recording, or it’s sent to a power amplifier to push your audio out the various speakers (Monitors as part of the Monitor Mix, and Main Arrays as part of the FOH [Front Of House], Theatre, or Arena Mix). Note again: nearly all pro live audio has both a Monitors feed and a Main (or Room/Theatre/Arena/House) feed.

This is because in order for the artists to hear each other while they perform, they may each need a personalized mix. In the most costly & sophisticated setups, every artist performing gets her (or his) own unique monitor mix which gives them precisely ‘their mix’ of drums, bass and chordal (guitar and/or keyboards) accompaniment instruments, so when it’s time to sing, one needn’t strain or move around to hear other key parts and make the musical arrangements work (as written and/or as finally rehearsed and planned). Hence the obvious need for thorough and timely sound checks! And to be honest, when dealing in the rarified realms of cinema and television production where the level of technologically-sophisticated aspects is very high (e.g., in an ADR [automatic dialogue replacement] suite doing post production for an SRK feature), attention to fine details is expected to be commensurately thorough.

All pro instrumentalists and singers (musical artists) are expected to be able to work well and listen carefully enough in performance that, e.g., if for any reason the Monitor system is “down” (not working), they/we can soldier on and work without a separate monitor speaker or earpiece setup. This does happen every so often. It’s never an excuse to quit!

When glitches and outages occur at live gigs, the true professionals deal with them in stride, and neither look to complain to nor to blame anyone else [and there’s zero budget for finger-pointing]. The show must go on. (Laying a “guilt trip” on the crew person who broke a connector (or forgot to set up a monitor speaker where you were used to having it) only identifies you as a non-team member. It can’t solve any issues at the last moment. So please: remain calm and kind! Also, don’t add to confusion by yanking on or swapping mic cables or re-routing them yourself, unless you want to shoulder the blame for any problems! All cables are typically marked and tested for specific mics, anyway—swapping them adds real confusion to the mix.)

So in most recording studios, we have another basic type of mic capsule: the condenser mic. This type of mic has nothing to do with air conditioning; it’s actually called an electret condenser, and it picks up sounds via a very-carefully made diaphragm that can be seen in the video here showing the “gold standard” mic (a Neumann Audio U87), seen in this video showing how it’s made. Such high-end mics are usually only found in recording studios, not as hand-held vocal mics on tour-venue stages. Yes, we have seen some global headlining acts using costly mics on tour, too. But seriously, at 8 or 9 lakhs apiece, one doesn’t want to leave one’s Neumann U87s lying around as bait for thieves.

But we do often see and use lower-cost (yet still good-quality) large-capsule condenser-type mics on stage. The main difference in how we set them up for use is that each mic has its own electronics to make its (small or large diaphragm) electret condenser capsule work, so the mic needs DC power, either in the form of a battery pack, or usually, we add what’s called “phantom power” of 48 volts DC to its cable (supplied by a built-in mixer mic pre-[amp]). Let’s examine it a bit more.

This gives the mic “enough juice” to be able to work with a condenser-type capsule. Fortunately, this “phantom power” is delivered invisibly (hence the origin of the term phantom) to the mic’s electronics via the mic cable (after we set its “+48V” switch to “On”). Dynamic (magnetic capsule) mics never need phantom 48V or replaceable battery power. Some mixers make it very obvious:

Phantom power

We call dynamic mic circuitry passive, and condenser mic circuitry active for the preceding examples of basic microphones. So passive capsule (dynamic) mics don’t require special added DC power, but active capsule (electret condenser) mics usually do either have special batteries and/or require (+48v. DC) phantom power.

Now let’s very briefly talk about Mixers. A mixer or mixing desk is a device for adding (mixing) the electrical signals (that we call audio programs or sources) together, so they will be heard at the same time in correct balance with/to each other.

Without mixers (that enable us to lower the intensity of each source or program, and each discrete such “signal” is generally allotted to one audio “channel” or “input path”) we lose all of the controls and flexibility they offer.

In recording studios, mixers are very complex and sophisticated. One recording desk/mixer may include 16, 32, 48, 64, or (often via remote control) over 128 channels for its inputs! In the current digital-audio domain, the number of channels is virtually unlimited (in other words, with the right robust digital platform, the software will support as many channels (or sources) as the engineer can manage in practice—we’ve heard of complex musical compositions in digital audio workstations [DAWs] with over 1,000 discrete “channels” or “tracks”). (Some Bollywood soundtracks certainly approach or exceed that level of complexity.)

Darkened theatres vary in size

Each mixer channel/input has its own electronics for doing basic tasks like pre-amplification, and may have audio tone shaping (like bass, mid-range, and treble controls), or may use what is called “outboard” (in contrast to “onboard” or “built-in”) audio processing circuitry. The general term for this equipment is “outboard/black box gear”. Some tech-friendly acts have their own bespoke ‘black boxes’ with specialized electronics to help them meet their act’s unique tech requirements and musical objectives.

For the purposes of a vocalist singing one lead or background vocal part, the usual practice for recording engineers is to add or subtract very little to or from a vocal track (as recorded more or less directly from a mic). This is also referred to as a “clean original vocal” track. Then, during later mixing and mastering phases of the recording process, the music director or producer may choose to add a little or maybe a lot more “processing” of the “raw vocal track” to achieve optimal sonic results (often by altering copies of the original vocals rather than degrading them permanently with effects that may have limited shelf lives).

Added processing may even be “dialed into” the original vocal recording, but generally, a little reverb/echo/delay for more “depth” is the most ever added to a basic vocal track. Some singers have very clear ideas about how their vocals should be handled (with X processing of Y or Z types, or maybe none as a rule, by preference, often from much past studio experience), especially in live performances! A bit of reverb/echo in a live mix generally helps vocals to thrive.

In this regard, here’s a very brief explanation: the vocal “signal” or “input” from the mic arrives at the mixer Input connector, usually in the form of a ‘balanced’ A/C audio electronic signal. While we digress in dealing with so much tech talk… very briefly, there are two types of mic cable runs/connections: unbalanced and balanced. “Balanced line” is the lower-noise, more professional way. It is compatible with most mixer or precision stand-alone mic preamplifiers.

Pro audio inputs are also called paired “non-inverting and inverting” complementary-pair inputs (which sounds like a technobabble mouthful, but is the only usable arrangement to support balanced-line pro-grade inputs). Balanced means the signal voltage swings both above (non-inverting) and below (inverting) the 0-volts (or ‘no audio signal’) state, whereas an unbalanced signal only changes as a positive swing above the ‘no signal’ 0-volts state. I hope that makes sense; it takes most people a while to grasp all of that background.

The inherently ‘magical’ aspect of “balanced” mic lines is very simple yet profound: the two wires used in a balanced line exist right next to each other (separated by usually only plastic “wire insulation jackets” as they’re called)… so this means that any nearby interference that induces current in one wire will do the same thing to the other wire!

However, because the wires are terminated at the same point in a polarized configuration with paired non-inverting plus inverting input, what occurs is that the interference present on one wire affects the Plus (+) side of the signal, yet the exact same interference is also present in the Minus (-) signal. Therefore, the interference signals are exactly seen as “out of phase” with each other, so they fully cancel each other out. Yay for electrical engineering! Interference and hum are mostly eliminated in all balanced pro audio/microphone runs (and most random electronic noise is thereby very-readily minimized, or effectively eliminated).

Now that I’ve used the term “phase” with respect to audio, let me say a bit more on it, because it’s very important.

Our voices use the air from our lungs being pushed past our vocal cords in very-quick puffs to produce a “vibrating” effect that, when done skillfully by a singer, gives a “pitch” or “note” or scale tone/frequency of “musical” sound. When we sing, the sound comes up from our throats past and vibrates our vocal cords, all in a direction going OUTWARDLY from our mouths. So those now “pitched” sounds reach the microphone diaphragm and move it (typically several hundred to maybe over a thousand cycles per second [cps]). [For reference, the highest note on a piano, far above any singer’s range, is 4186 cps; sopranos (even in opera) top out well under 1500 cps].

This movement pushing the mic diaphragm occurs in the same direction to move the mic diaphragm’s voice coil back and forth near the mic’s permanent magnet, or in a condenser mic, so the electret surfaces vibrate like dynamic mic diaphragms, and either way, both mics create an audio “signal” of low voltage to be passed along to the preamplifier in the same basic way, with essentially-identical results. Details of various mic types and how they’re made and used are available online, e.g., on this site by Shure Bros.

Note that this pushing of the mic diaphragm or condenser capsule diaphragm at first causes a positive-going signal, and is moved by the little air puffs (or resonant vocal vibrations as in humming sustained in our mouth and throat/larynx). If we were to intentionally reverse the wires from a mic line (balanced or unbalanced), this would cause the mic’s signal to be reversed (or 180 degrees outofphase).

The business of an amplifier is to increase the power of a signal to make it strong enough to push a loudspeaker driver/cone out in a “forward” direction to match the frequency (pitch) of the signal. If one taps on a mic and sees a (not covered by a cabinet grille) bass speaker cone move inward instead of outward, one is witnessing an out-of-phase condition (most likely caused by a mistakenly-wired) mic in use. While we did note it as a possible dumb prank, FYI, some sound techs have actually been fired from tour teams for giving artists improperly-wired mics (or so I was told)!

Therefore, the polarity (e.g., + / -) in its internal circuitry, if any) of a microphone‘s wiring (both internally and wires/cords connecting it to the next part of an audio signal path) matters quite a lot. It can be a subtle thing to observe, and often takes a trained/more experienced ear to catch, but many experienced sound engineers can detect “out-of-phase” mic audio.

The best audio engineers are paid to catch such issues before they cause other problems, and some use tricks or signal generators to be clear about things like mic phase especially in live venues. (In summary, audio techs refer to elements of the system being “phased” means already tested and debugged if necessary to fix any problems.) Bottom line in LIVE AUDIO (especially on tour in unfamiliar venues): take absolutely nothing for granted. Test, repair if necessary, and get it right for setting basic mic levels for every channel/artist in the sound check.

Please note that when multiple singers use mics in close proximity, whenever ANY such mic is wired out-of-phase, it can cause unpredictable issues for the overall sound (and as implied earlier, can upset some global-star artists in rather unpredictable ways).

For example, let’s say we have four singers singing in close harmony (4-note chords). In this example, they’re just singing without mics. Now imagine how the vocal mix changes when one or more of the singers turns around and sings in the opposite direction—it’s not a happy thing! We may be able to hear all of the parts, but since we’re probably hearing one or more parts only after they’ve bounced off back walls or something, the overall mix is basically messed up.

Because acoustics is a rather complex science, we may find that such results and how we perceive (or fail to notice) them can very well manifest in rather unexpected and/or unpredictable ways. Fortunately, the fields of audio and acoustics have attracted many great minds, including notables of Indian ancestry for several decades.

But in summary, please: trust me, Dear Music Lover… you NEVER want the mic you’re using to be wired incorrectly (as in being simply out-of-phase due to a wiring mistake), or else you probably won’t like the results. While this may ‘sound musical’ and will still convey ‘your vocal’ to the next link in the audio “signal chain”, it will nevertheless be out-of-phase, and in a sense, will sound like you are facing away from the listeners instead of toward them. It’s not very obvious to the untrained ear, but among pranksters (and we have them in all areas of the entertainment industry), it’s one way to “mess with” an artist in a rather non-obvious way. Don’t fall for that trick (or innocent error) if you can catch it!

To wrap up this talk about mixers and mics, when mixers are used to “patch in” (add) audio signal processing (like audio compression or extensive digital effects), this is done using a mixer feature called Effects Send & Return (aka an Effects Loop). It’s actually quite straightforward, although since it’s not always used or taught in basic audio engineering, many sound techs ignore and/or never learn how it’s done. But we can explain it here very readily…

We begin with our mic’s audio signal in one channel of our mixer. We use the Send jack of its channel to connect (using a “patch cable”) the signal to the Input jack of some external processing device (or “outboard gear”). Then we connect another patch cable from the Output of the external/outboard gear back to the input labeled Return on the original mixer channel. In brief, we call such setups Effects Loops (because what goes out is modified by the “outboard gear” and looped right back into the mixer for final-mix level adjustments—as the resulting sound signal is added to/faded out of the mix by the sound tech or recording engineer adjusting the mix—now including however much additional tone colour or other processing is wanted).

Note that all such Effects Sends & Returns also have a switch to stop (override) all of the additional effects/processing. Obviously that switch is usually labeled something like Bypass/Clean. Other names for “defeating” the external processing by switch: “Normal”, “Out” or “Flat”. Out/In refers to whether or not the processing is included in the signal path.

So as a singer, you will very rarely if ever be asked to make complex mixing decisions and adjustments. But to the degree you become educated and experienced about such things, your ear can help to guide in making such decisions or at least suggesting what you think might improve the final results.

  • Stage equipment

So every performance will have needs for various types of equipment: mics and mic stands (in a TV studio, mics are often put on “boom arms” to be suspended over the “talent” in order to be able to pick up sounds without being seen in the visual frame), mixers (which are often either positioned in a spot convenient to let the sound tech/mixer see and hear the entire band or ensemble and to then mix the various parts effectively from a sort of middle-of-the-venue vantage point—which may also be at the very back of the hall, perhaps in a room meant also for a movie or [in a meeting/teaching facility, a] slide projector), other talent- or house-staff-operated equipment (lighting, props, backdrops, settings), etc. Stages can quickly become like obstacle courses for artists.

We have yet another semi-technical factor to consider in all of this audio gear setup for live and/or to-be-recorded music audio: this is that every mic or musical instrument (e.g., electric guitar/bass) also has what is called a nominal impedance.

So impedance is basically the alternating-current version of resistance in a direct-current circuit. Technically, all audio is treated like an AC signal, even when it’s actually delivered between connections as DC. (This is because sound waves move both forward and backward—like AC, they move both above and below zero [no signal] to produce musical sound waveforms). (The simple fact of impedance is that signal chains where connected must be at compatible impedance values. We may or may not explore such detailed matters here on my blog-site. Feel free to read up on this tech stuff at your leisure.)

Okay… that was quite an exposition for our first lesson on mics, mixers and related audio gear.

Future posts will get into aspects of reverb, compression and other processing. Again, singers are seldom expected to be conversant in all of this techie-talk terminology and its actual state-of-the-art practices. However, it also “never hurts to learn” about the tools of one’s trade!

Another important thing to know about pro audio is that its development has closely paralleled and been influenced by the motion picture (film/movie) industry. Early “talkie” films from 1927 onward very much pioneered sound recording practices (like hiding microphones and having audio experts carefully monitoring the recording and being ready to assist, adjusting gain as needed for each scene) and films (originally using a rather high-fidelity optical [not digital!] transcription method) offered some of the best technical platforms for further audio development, and even present-day feature films have continued to evolve and use best-available technologies.

A final few [yet important] thoughts on mics:

If it’s not on a stand, hold the mic gently… unless you want your audience to see you looking a bit desperate. Except for those times when you’re sure that the audio system is not supporting your vocals at a good high-enough level, keep the mic roughly 8-12 cm (3-5 inches) from your mouth. As noted above, it is almost always a BAD IDEA to cup your hands over a stand mic to get more volume, as it often causes feedback (a very-loud, unmusical whistle). It’s also quite awkward to cup a hand-held mic! So (unless you’re also skillfully playing a harmonica), it’s definitely best not to cup the mic.

  • Pop Filters and Windscreens

My final topics here are pop filters and windscreens. The latter have nothing to do with driving, except when we’re in a vehicle that’s moving while we sing. Windscreens can have a small or profound impact on the final audio, and what they do is simple yet effective: they break up the turbulence that can otherwise reach the mic diaphragm as a whooshing noise, and basically ruin the audio completely. By breaking up the turbulence noise, windscreens effectively reduce it to a very slight whisper, keeping it from ruining the audio [containing your vocals, or other audio content]. In virtually all outdoor setups, windscreens are required in order to ensure listenable results. If the gig is outdoors but on a very quiet, clear day, it’s possible to skip using windscreens. But even a slight breeze can ruin a mic’s audio, so it’s best to avoid taking unnecessary chances!

Top pros like the great Arijit Singh also use great studio gear—with pop filters just like the rest of us!

Pop filters, as you see me and or other singers use on nearly every song, are also called plosive filters. They simply keep our “plosives” (hard consonant pronunciations of Bs and Ps) from popping annoyingly onto, thereby ruining our vocal tracks. That’s really all they do; while there are digital processing alternatives, the simple pop screen we use also works well (yet it requires no power or complexity). It also catches any tiny spittle droplets emanating from our mouths (hygiene is especially keen these days).

Windscreens are mainly for outdoor use, but are often left covering mics even indoors. Their effectiveness against the very annoying noise from wind blowing through a mic capsule (producing a slow whoosh sound) is proven to be excellent. If possible, never use a mic outdoors on a day with any wind—without a decent windscreen.

Finally, I want to mention two more things: mic colour and styling, and wireless considerations.

You may have noticed that Indian Idol and other Sony TV shows produced in Mumbai have gone to using all-golden coloured microphones. They also happen to be wireless.

Regarding the value of using wireless technology for microphones, it’s already existed in the field for decades, and some of the newer models also have excellent audio performance. One way we measure audio performance is to test mics in an anechoic (well sound-isolated) chamber, revealing how accurately they pick up a full audible spectrum (from very low bass to highest treble sounds) without colouring (distorting) the audio response.

One point we want to state is that the gold-coloured mic has exactly-identical sonic performance when compared to an otherwise-identical silver model mic. So its colour is merely an esthetic choice (that some might claim looks good on TV video alongside the wardrobe choices found on Indian reality programs). Also, one can delve deeply on nearly any tech topic with some online research.

Wireless-capable mics save us from stumbling over any mic cables. That may seem insignificant to those who’ve never been on a small stage with a gaggle of instrumentalists crowded together along with a myriad of music electronics. But trust us: any way to simplify a stage setup is welcome. Wireless mics also connect invisibly; there are also no physical connections to check, test and maintain. Of course the main objective is great music. So fortunately, decades in, wireless has become quite commonplace. It is that good—by now! Even recent improvements to Bluetooth make wireless audio far more practical plus more affordable than ever before.

A few more points on the wireless mic thing: first, it’s not a panacea. We are usually limited in range to about 50 metres’ distance from the wireless mic receiver. It’s very important that we know where it is, so we don’t wander into the crowd too far and end up with a non-working mic, or find ourselves shifting nervously around large speaker arrays/cabinets in order to avoid interference (as our mic’s response goes on and off with no obvious cause like the aforementioned switch). Another possible item of interest is radio interference (which although it’s not a real factor for balanced-line pro mics, may still occur with home-use grade unbalanced-line wired and some cheaper wireless mics).

Another very-important matter is that there are not only wearable monitors, there are certainly also wearable wireless mics. The age of inexpensive Bluetooth devices has finally put such gear in the reach of less-wealthy users… my advice to you as an aspiring artist is to consult with some experts and spend time trying out various brands and levels of audio gear before investing in such equipment for your needs. Often better TV and film studios provide talent with good-quality wireless mics for use in their appearances on a given show. While universal-fit choices are arguably rather compromised compared with carefully fitted top-of-the line custom-fitted models, they can be very useful for comparing common features.

I can assure you that when your pro-quality (and yes, costly) in-ear monitors are fitted perfectly, your ability to hear yourself (and if your tech crew is great, like Pritam’s, your mix will be to your liking as well) will be something that just works transparently without issues, and you hardly have to think about it. That’s in stark contrast to the quick-and-cheapo setups one may find in some open-mic nights at local clubs (where many singers get first chances to “show their gifts” in public).

In the age of Covid-19 (and future pathogenic threats), the idea of sharing earpieces with strangers may be substantially less attractive. But as I often advise my private students: top pros don’t wince and complain over the small stuff (Look for antiseptic wipes?). Note that in digital entertainment, it’s all small stuff, too. In a manner of speaking (meaning nothing but 1s and 0s). If concerns about shared surfaces arise, an expedient (pre-packed) cotton swab with alcohol may be just what your doctor expected you to use on an already-used earpiece or headset.

So whether all of this mics, mixers and stage gear shop-talk/advice seems like useful knowledge for singers, I can assure you that it may come in handy. Maybe if it does, you can thank me (and my poignantly-piquant web team who together with me produced these pearls of Shop-Talk wisdom for you), Dear Music Lover. (Thank you for reading and learning. I’m confident that we’re saving at least one or a few playback/audio people from some of the most awkward moments of the otherwise uninitiated.)

So, who makes the best audio gear and how much does it cost? How to integrate and hook it all together? What about all of the various “outboard gear” that we only noted in passing here? I’ll cover some of the salient aspects of Vocal Processing in a future post, but this much so far is plenty of the shop-talk rhetoric for us now.

Feel free to send us your questions about what we’ve written here, and we may include a question/answer section soon, too. You can reach us at iantara (at) icloud (wise humans can deduce the actual dotcom address). Keep doing your best singing! Mwah!

Stay safe, keep rocking a singer’s mask around others, and when you’re cleared to receive your vaccination(s), please, Dear Music Lover: do the responsible community-minded thing and get yours! Also, 30-sec. hand washing and social distancing: these can save lives by reducing the spread of infections.

Also always remember: we love ❤️ you madly too—and eventually (as those who decide haven’t yet said exactly when), we’ll see you (and you’ll hear us) again watching and listening to us at the MOVIES!




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