Tag Archives: Microphones

The Grand Experiment

A plan for an objective comparison of the SM58 to various other “live sound” microphones.

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.

Purpose And Explanation

Ever since The Small Venue Survivalist became a reality, I have wanted to do a big experiment. I’ve been itching to round up a bunch of microphones that can be purchased for either below, or slightly above the price point of the SM58, and then to objectively compare them to an SM58. (The Shure SM58 continues to be an industry standard microphone that is recognized and accepted everywhere as a sound-reinforcement tool.)

The key word above is “objectively.” Finding subjective microphone comparisons isn’t too hard. Sweetwater just put together (in 2017) a massive studio-mic shootout, and it was subjective. That is, the measurement data is audio files that you must listen to. This isn’t a bad thing, and it makes sense for studio mics – what matters most is how the mic sounds to you. Listening tests are everywhere, and they have their place.

In live audio, though, the mic’s sound is only one factor amongst many important variables. Further, these variables can be quantified. Resistance to mechanically-induced noise can be expressed as a decibel number. So can resistance to wind noise. So can feedback rejection. Knowing how different transducers stack up to one another is critical for making good purchasing decisions, and yet this kind of quantitative information just doesn’t seem to be available.

So, it seems that some attempt at compiling such measurements might be helpful.

Planned Experimental Procedure

Measure Proximity Effect

1) Generate a 100Hz tone through a loudspeaker at a repeatable SPL.

2) Place the microphone such that it is pointed directly at the center of the driver producing the tone. The front of the grill should be 6 inches from the loudspeaker baffle.

3) Establish an input level from the microphone, and note the value.

4) Without changing the orientation of the microphone relative to the driver, move the microphone to a point where the front of the grill is 1 inch from the loudspeaker baffle.

5) Note the difference in the input level, relative to the level obtained in step 3.

Assumptions: Microphones with greater resistance to proximity effect will exhibit a smaller level differential. Greater proximity effect resistance is considered desirable.

Establish “Equivalent Gain” For Further Testing

1) Place a monitor loudspeaker on the floor, and position the microphone on a tripod stand. The stand leg nearest the monitor should be 3 feet from the monitor enclosure.

2) Set the height of the microphone stand to a repeatable position that would be appropriate for an average-height performer.

3) Changing the height of the microphone as little as possible, point the microphone directly at the center of the monitor.

4) Generate pink-noise through the monitor at a repeatable SPL.

5) Using a meter capable of RMS averaging, establish a -20 dBFS RMS input level.

Measure Mechanical Noise Susceptibility

1) Set the microphone such that it is parallel to the floor.

2) Directly above the point where the microphone grill meets the body, hold a solid, semi-rigid object (like an eraser, or small rubber ball) 6 inches over the mic.

3) Allow the object to fall and strike the microphone.

4) Note the peak input level created by the strike.

Assumptions: Microphones with greater resistance to mechanically induced noise will exhibit a lower input level. Greater resistance to mechanically induced noise is considered desirable.

Measure Wind Noise Susceptibility

1) Position the microphone on the stand such that it is parallel to the floor.

2) Place a small fan (or other source of airflow which has repeatable windspeed and air displacement volume) 6 inches from the mic’s grill.

3) Activate the fan for 10 seconds. Note the peak input level created.

Assumptions: Microphones with greater resistance to wind noise will exhibit a lower input level. Greater resistance to wind noise is considered desirable.

Measure Feedback Resistance

1) Set the microphone in a working position. For cardioid mics, the rear of the microphone should be pointed directly at the monitor. For supercardioid and hypercardioid mics, the the microphone should be parallel with the floor.

2a) SM58 ONLY: Set a send level to the monitor that is just below noticeable ringing/ feedback.

2b) Use the send level determined in 2a to create loop-gain for the microphone.

3) Set a delay of 1000ms to the monitor.

4) Begin a recording of the mic’s output.

5) Generate a 500ms burst of pink-noise through the monitor. Allow the delayed feedback loop to sound four times.

6) Stop the recording, and make note of the peak level of the fourth repeat of the loop.

Assumptions: Microphones with greater feedback resistance will exhibit a lower input level on the fourth repeat. Greater feedback resistance is considered desirable.

Measure Cupping Resistance

1) Mute the send from the microphone to the monitor.

2) Obtain a frequency magnitude measurement of the microphone in the working position, using the monitor as the test audio source.

3) Place a hand around as much of the mic’s windscreen as is possible.

4) Re-run the frequency magnitude measurement.

5) On the “cupped” measurement, note the difference between the highest response peak, and that frequency’s level on the normal measurement.

Assumptions: Microphones with greater cupping resistance will exhibit a smaller level differential between the highest peak of the cupped response and that frequency’s magnitude on the normal trace. Greater cupping resistance is considered desirable.


Measuring A Cupped Mic

What you might think would happen isn’t what happens.

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 most popular article on this site to date is the one where I talk about why cupping a vocal mic is generally a “bad things category” sort of experience. In that piece, I explain some general issues with wrapping one’s hand around a microphone grill, but there’s something I didn’t do:

I didn’t measure anything.

That reality finally dawned on me, so I decided to do a quck-n-dirty experiment on how a microphone’s transfer function changes when cupping comes into play. Different mics will do different things, so any measurement is only valid for one mic in one situation. However, even if the results can’t truly be generalized, they are illuminating.

In the following picture, the red trace is a mic pointing away from a speaker, as you would want to happen in monitor-world. The black trace is the mic in the same position, except with my hand covering a large portion of the windscreen mesh.

You would think that covering a large part of the mic’s business-end would kill off a lot of midrange and high-frequency information, but the measurement says otherwise. The high-mid and HF information is actually rather hotter, with large peaks at 1800 Hz, 3900 Hz, and 9000 Hz. The low frequency response below 200 Hz is also given a small kick in the pants. Overall, the microphone transfer function is “wild,” with more pronounced differences between peaks and dips.

The upshot? The transducer’s feedback characteristics get harder to manage, and the sonic characteristics of the unit begin to favor the most annoying parts of the audible spectrum.

Like I said, this experiment is only valid for one mic (a Sennheiser e822s that I had handy). At the same time, my experience is that other mics have “cupping behavior” which is not entirely dissimilar.


How To Buy A Microphone For Live Performance

A guest-post for Schwilly Family Musicians

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.

vintage_microphone-wallpaper-1280x800

From the article: “At the same time, though, a LOT of mics that are great for recording are a giant ball of trouble for live audio. Sure, they sound perfect when you’re in a vocal booth with headphones on, but that’s at least one whole universe removed from the brutal world of concert sound. They’re too fragile, too finicky, too heavy, their pickup patterns are too wide, and you can’t get close enough to them to leverage your vocal power.”


The whole thing is available for free, so go ahead and take a gander.


I Am SO Over Wireless

Another “Schwilly” article.

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.

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

“If you are an audio person or a musician, someone you know will eventually want to do things involving audio (or data representing audio) and radio waves. They will think that such an idea is brilliant. They will think it will be so very nifty to be un-tethered and free, wild like the stallions and mares which once loped across the mighty plains of America’s central expanse, majestic in their equine kingship ov-

Yeah. About that. Don’t believe it. Wireless is a pain in the donkey.”


Read the whole thing for free at Schwilly Family Musicians.


The Loudest Thing At The Capsule Always Wins

Mics are not “smart,” and they can’t “reach.” Whatever pressure event is happening at the capsule is what they turn into electricity.

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.

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

“A big, sort of “omnibus” myth is that microphones have some sort of magical ability to discriminate between what you want them to pick up and everything else. This myth manifests in such (understandable but spurious) notions like mics with higher sensitivity being necessary for quiet singers. The idea is that higher sensitivity allows the mic to “reach” farther from itself, and grab the sound of the vocalist. Also, the thought includes a guess that feedback might be reduced, because less post-mic gain is applied.

Like I said, this is understandable, but inaccurate.”


The entire article is available, for free, at Schwilly Family Musicians.


The Sublime Beauty Of Cheap, Old, Dinged-Up Gear

Some things can be used, and used hard, without worry.

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.

I really do think that classy gear is a good idea in the general case. I think it sends a very important signal when a band walks into a room, and their overwhelming impression is that of equipment which is well-maintained and worth a couple of dollars. When a room is filled with boxes and bits that all look like they’re about to fail, the gigs in that room stand a good chance of being trouble-filled. In that case, musician anxiety is completely justified.

In the past, I have made updates to gear almost purely for the sake of “politics.” I don’t regret it.

At the same time, though, “new n’ shiny” equipment isn’t a guarantee of success. I’ve had new gear that developed problems very quickly, but more than that, new and spendy gear tends to make you ginger (in the timid sense). You can end up being so worried about something getting scratched up or de-spec’d that you forget the purpose of the device: It’s there to be used.

And that’s where the sublime beauty of inexpensive, well-worn equipment comes in. You’ve found a hidden gem, used it successfully in the past, will probably keep using it successfully in the future, and you can even abuse it a bit in the name of experimentation.

Case Study: Regular Kick Mics Are Boring

I’ve used spendy kick mics, and I’ve used cheap kick mics. They’ve all sounded pretty okay. The spendy ones are pre-tuned to sound more impressive, and that’s cool enough.

…but, you know, I find the whole “kick mic” thing to be kinda boring. It’s all just a bunch of iteration or imitation on making a large-diaphragm dynamic. Different mics do, of course, exhibit different flavors, but there’s a point where it all seems pretty generic. It doesn’t help that folks are so “conditioned” by that generic-ness – that is, if it doesn’t LOOK like a kick mic, it can’t be any good. (And, if it doesn’t COST like a kick mic, it can’t be any good.)

I once had a player inquire after a transducer I used on his bass drum. He seemed pretty interested in it based on how it worked during the show, and wanted to know how expensive it was. I told him, and he was totally turned OFF…by the mic NOT costing $200. He stated, “I’m only interested in expensive mics,” and in my head, I’m going, “Why? This one did a good enough job that you started asking questions about it. Doesn’t that tell you something?”

Anyway, the homogeneity of contemporary kick mic-ery is just getting dull for me. It’s like how modern car manufacturers are terrified to “color outside the lines” with any consumer model.

To get un-bored, I’ve started doing things that expose the greatness of “cheap, old, and dinged up.” In the past, I tried (and generally enjoyed) using a Behringer ECM8000 for bass drum duty. Mine was from back when they were only $40, had been used quite a bit, and had been dropped a few times. This was not a pristine, hardwood-cased, ultra-precision measurement mic that would be a real bear to replace. It was a knock-around unit that I had gotten my money out of, so if my experiment killed it I would not be enduring a tragedy.

And it really worked. Its small diameter made it easy to maneuver inside kick ports, and its long body made it easy to get a good ways inside those same kick ports. The omni pattern had its downsides, certainly. Getting the drum to the point of being “stupid loud” in FOH or the drumfill wasn’t going to happen, but that’s pretty rare for me. At an academic level, I’m sure the tiny diaphragm had no trouble reacting quickly to transients, although it’s not like I noticed anything dramatic. Mostly, the mic “sounded like a drum to me” without having to be exactly like every other bass-drum mic you’re likely to find. The point was to see if it could work, and it definitely did.

My current “thing” bears a certain similarity, only on the other end of the condenser spectrum. I have an old, very beat-up MXL 990 LDC, which I got when they were $20 cheaper. I thought to myself, “I wonder what happens if I get a bar-towel and toss this in a kick drum?” What I found out is that it works very nicely. The mic does seem to lightly distort, but the distortion is sorta nifty. I’m also freed from being required to use a stand. The 990 might die from this someday, but it’s held up well so far. Plus, again, it was cheap, already well used, and definitely not in pristine condition. I don’t have to worry about it.

Inoculation Against Worry Makes You Nicer

Obviously, an unworried relationship with your gear is good for you, but it’s also good in a political sense. Consternation over having a precious and unblemished item potentially damaged can make you jumpy and unpleasant to be around. There are folks who are so touchy about their rigs that you wonder how they can get any work done.

Of course, an overall attitude of “this stuff is meant to be used” is needed. Live-audio is a rough and tumble affair, and some things that you’ve invested in just aren’t going to make it out alive. Knowing this about everything, from the really expensive bits to the $20 mic that’s surprisingly brilliant, helps you to maintain perspective and calmness.

The thing with affordable equipment (that you’ve managed to hold on to and really use) is that it feeds this attitude. You don’t have to panic about it being scuffed up, dropped, misplaced, or finally going out with a bang. As such, you can be calm with people. You don’t have to jump down someone’s throat if they’re careless, or if there’s a genuine accident. It’s easy to see that the stuff is just stuff, and while recklessness isn’t a great idea, everything that has a beginning also has an end. If you got your money out of a piece of equipment, you can just shrug and say that it had a good life.

Have some nice gear around, especially for the purpose of public-relations, but don’t forget to keep some toys that you can “leave out in the rain.” Those can be the most fun.


The Best Upgrades

If you’re going to upgrade something, try to upgrade at the ends of your signal chain.

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.

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

This business is so “magical gear” oriented that it hurts people. I don’t know how many bankruptcies, strained relationships, failed businesses, and heartburn prescriptions have resulted from gear acquisition, but my bet is that the number is somewhere between “a lot” and “a gazillion.” Audio humans spend a ton of money, and what’s worse, there’s a tendency to spend it on the wrong things. The search for better sound is a journey that’s often undertaken through a path that leads into the deep underbrush of mythology, and that’s a recipe for getting lost.

One perennial (and expensive) mistake is pursuing upgrades to the wrong parts of the signal path. Folks get incredibly wound up about the sound quality of things like consoles, poweramps, preamps, and even cables. They thrash around, trying to figure out why things don’t sound “just so,” and run huge bills as they do. In the process, they miss opportunities to upgrade the bits that would really matter.

If we’re talking about the part of the signal chain that involves electricity, the bits that matter are at the ends.

Transduction Is Hard

Let’s start with what I’m not saying: I’m not saying that the middle of the signal chain is trivial. It isn’t. A lot of work has been done to get us to where we are now in terms of distortion and SNR. Very smart people have worked for decades to design and miniaturize the components and subassemblies that make pro-audio go. What I am saying, though, is that signal routing, combining, and gain adjustment ARE trivial when compared to signal transduction.

For instance, let’s take the INA217, an instrumentation amplifier that can be used to build microphone preamps. At around 68 dB of gain, (the base 10 logarithm of 2500, multiplied by 20), the unit maintains a bandwidth beyond the audible range. Nifty, eh?

You can buy one for less than $7. Buy in quantity, and the per-unit cost is less than half that.

Or, take a mix bus from a console. The heart of a mix bus is either electrical or mathematical summing. Addition, I mean. The basic process is incredibly simple, and though the circuits do have some important particulars, they are not difficult for an electrical engineer to design. (And, that’s assuming that they actually get designed anymore. I strongly suspect that most folks are grabbing an existing design from a library and extending it to meet a certain specification.) Insofar as I can determine, there is no secret sauce to a summing bus. There are better components that you can specify, and due diligence is required to prevent external noise from corrupting the signals you actually want to use, but there’s no “magical addition process” that some folks have and some don’t.

“Doing stuff” to electricity that’s already electricity is pretty darn simple.

Life gets far more complicated when you’re trying to change sound into electricity or back again. The vagaries of directional microphone tuning, for instance, are strange enough that they don’t even make it into patent applications. They’re kept locked away as trade secrets. Microphone diaphragms aren’t really something you can build with ingredients found in your kitchen (good luck with working on materials that are only microns thick). Just about any decision you make will probably affect the whole-device transfer function in a way that’s easy to hear. On the output side, the tradeoffs associated with making a loudspeaker driver are both numerous and enormous. Everything matters, from the diaphragm material on up. The problem compounds when you start putting those drivers in boxes and attaching them to horns. Big drivers move lots of air, but don’t start or stop as fast as small units. The box might be resonating in a strange way. Just how bad do things get when the loudspeaker is run below the box tuning? Again, a small design change is likely to have audible results.

Manufacturers continue to iterate on transducer designs in ways that appear “fundamental” to the layman, whereas iteration on other products is more about incremental improvements and feature additions.

What this all amounts to is that a transduction improvement is far more likely to be of obvious and significant benefit than an upgrade in the “pure electricity” path.

Beyond The Chain

Upgrading the ends of the signal chain is a concept that works even beyond the electro-acoustical sense.

Let’s say I have the greatest microphone ever made. The entire thing is built from pure “unobtainium.” It is perfectly linear from 1 Hz to 30 kHz, and has infinitely fast transient response. It’s not even physically possible for this microphone to exist, it’s so good. I put that microphone in front of a singer with an annoying overtone in their voice. Does that singer sound good?

No. The microphone perfectly captures that ugly harmonic. If I had a choice, I would prefer an upgrade to the ultimate end of the signal chain: The signal source. I’ll take an amazing singer into an okay mic at any time, but a great mic in front of a bad singer doesn’t help very much.

Let’s also say that I have the greatest loudspeaker ever constructed. Its transfer function is perfectly flat, with flawless phase response. This mythical device is then placed in an aircraft hangar built of metal. The acoustical environment’s insane reflections and smeared transients result in a sound that’s almost completely unintelligible, and even a bit painful.

A “basically okay” loudspeaker in a great room would be much better.

If you’re going to undertake some sort of sonic improvement, you want to do all you can to upgrade things that are as close to the endpoints as possible. If you’re not getting the sound you want, look at source quality, room acoustics, mic capability, and loudspeaker fidelity first.


Public Speaking, PA Systems, And You

Just like a concert, what we want is the best possible show at the lowest possible gain.

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.

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

The inspiration for today’s article comes from Resli Costabell, a corporate trainer and professional speaker. She dropped by the Small Venue Survivalist’s Facebook page a few days ago, and left a note:

‘I know you’re about playing music, and I’d also be keen to hear your tips for speakers. Not speakers as in “big black box that pours out sound.” Speakers as in “human being talking.”‘

The great thing about sound for any event, whether that event is based on music or spoken word, is that the physical principles involved don’t change. At all. Sure, there may be differences in specific application, but all the science remains as it has always been. As such, any problems that occur will tend to crop up when there’s an attempt to “Captain Kirk” a situation: “Ya can’na change the laws of physics, Cap’n!”

As I’ve said before, sound reinforcement is all about the best possible show at the lowest possible gain. The first thing we have to figure out, then, is what is critical to the success of the event, and what isn’t. I, and many other audio humans, have been witness to situations where a non-critical element becomes prioritized to the point where it wrecks the experience of the critical parts. The major culprit for public speaking?

Visual Orientation At The Expense Of Sound

This is not, in any sense, about sound craftspersons believing that they are at the center of the Universe. This is about how audio itself IS the center of the Universe at any event where the primary mode for you to impart information is speech. If your engagement with your audience is based on an auditory event (talking, that is), then everything else MUST come second to that. It’s perfectly fine for that second-place finish to be “close.” Yes, you should look professional. Yes, your slide deck should be projected as beautifully as is possible. Yes, it’s good for you to be appropriately animated on stage. Yes, you should be able to hold yourself in a comfortable way. Yes, it’s great to be able to get right up to the first row of attendees.

Yes, but…

If any of that gets in the way of you being heard clearly and comfortably, then it has to take a back seat. If it doesn’t take a back seat, then the brutal, uncompromising, feral, and downright vicious physics of sound will begin clawing and biting at your event’s success. Gain is added to mics until the system begins to noticeably destabilize. More and more equalization is applied, assuming someone is around to apply it. The sound gets more and more “hacked up.” Eventually, an unpleasant equilibrium is reached where your talk is perhaps audible, yet of an irritating tonality, tough to actually parse, and given to “ringing” in a distracting manner.

Don’t be distraught! There are things you can do to fix this.

Prioritizing Audibility

Avoid Scrimping On Audio

An alarming number of presenters will spend enormous amounts of money on signage, computer graphics, handouts, goodies, nifty chairs, nice tables, uplighting, gobo projectors, and floral arrangements…and then have almost nothing left for audio. This is an inappropriate prioritization if speaking is the core of your audience engagement.

Instead, get your sound right first. If you are having AV provided for you, go for the best system available that makes sense. You don’t need a rock-concert rig to speak to 100 people in a breakout room, but a nice mic, a flexible mixer, and some decent loudspeakers on sticks are a much better approach than some $20/ day “mini-PA” that sits on a table. You might also want to consider owning your own PA. A few bits and pieces can sometimes outperform an installed AV system. Also, it can be very nice to have a flexible “front end” if the installed coverage is great…but the controls are poor.

This point is especially important because it underpins the rest of my particulars. With all of my following concepts, I am assuming that a correctly set up and reasonably tuned PA system is being employed. A sound system that is simply inadequate can not be correctly setup or reasonably tuned to best fit your presentation. A very nice system that is not working properly is not very likely to meet your needs.

Get Help

A competent sound crew, able to listen as though they were audience members, is an enormous help to your event. If some part of the system begins to misbehave, a dedicated craftsperson can begin to act on the problem while you continue on. Small issues can be corrected quickly, without you having to think about them. This isn’t even to mention that you can do other things while the audio rig is being set up.

The alternative is that you have to do double duty. There is a point where you alone simply cannot maintain your presentation’s flow and manage audio problems in parallel. Also, it is very hard for any “set and forget” system (whether meaningfully automated or not) to compete with a knowledgeable human operator wielding an appropriate set of tools. A crew, even if it’s just one trustworthy helper, that’s dedicated to your event alone does cost a bit more. The dividends paid from that investment can be enormous, though.

Mic Choice And Technique

For the love of all that is good, please get over any hangups you have regarding blocking your face with a microphone. Microphones work best when the apparent sound pressure of your voice is VERY large when compared to the apparent sound pressure of anything else – the PA system being a valid example of “anything else.” The louder your voice is at the capsule, the less gain is needed. Making your voice the loudest thing at the mic capsule means using a directional mic and holding that mic as close to your mouth as you can. If the overall result of sounds bad because of plosives (“p” and “b” sounds which “boom” or are otherwise problematic), then change the mic position so that the airstream from your mouth is less direct. You can try parking the front of the mic on the tip of your nose, or just below your bottom lip. Be careful not to tilt the mic so that you’re effectively talking into the side of the element. The front is where a directional mic is most sensitive and sounds the best.

Yes, holding a mic in this way is going to cause some sight lines to your face to not be the best. Remember, please, that the audibility of your speech must be the winner of all arguments. I do sympathize with the needs and wants of people running video. I recommend a cordial, polite, and firm stance that three-quarter and profile shots be used if there is a concern over straight-on views.

Implicit in the first paragraph is that a handheld mic is best. A headworn unit can be okay, but it must be placed carefully. Again, the mic should be as close to your mouth as is possible, but bear in mind that many headworns are not meant to be placed directly in front of the mouth. Their “pop-and-blast” filtering is inadequate for that approach. The corner of your mouth is the target area for many of these mics. Get the mic as close to that area as you can, and then ensure that it stays where you’ve put it.

Under no circumstances should your preferred solution be a lavalier mic attached to your jacket or shirt. Holding a directional mic at the level of your chest would not be acceptable, so I have no idea why doing the same thing with an omnidirectional unit would be considered a reasonable approach. With speech, lavalier microphones are indeed useful for “after the fact” video productions. For realtime sound-reinforcement they are simply inappropriate, and if anyone disagrees with me on that point, well, I just don’t care. I will gladly enter a competition where a properly placed lavalier and a properly placed handheld are set against each other in a battle of gain-before-feedback; I am confident that the handheld will be victorious.

Vocal Power

Just a while ago I said that, “Microphones work best when the apparent sound pressure of your voice is VERY large when compared to the apparent sound pressure of anything else.” This really is THE first principle of getting things right when speaking publicly with a PA. In the same way as a powerful singer makes concert sound much easier, so too does a powerful speaker. In fact, the PA system as a whole works best when your voice’s acoustical output is a “very hot” signal.

Speak as loudly as you can without straining. Straining your voice will tire you out, maybe damage your vocal cords, and produce unpleasant overtones that irritate your audience. Without getting to that point, speak as though you had no mic and no PA system. This will help ensure that the direct sound of your voice from your mouth is the largest possible acoustical signal the microphone can encounter. You probably will not be “too loud,” but if you are (and if you’ve followed my advice about getting good gear and good help), you can very easily be turned down. Effectively reducing a system’s gain is trivial when compared to increasing the gain. Reducing overall system gain reduces “smear” from sound looping back through the system, which helps make the presentation sound better.

Where Do You Stand?

Following on some more from my “first principle,” you should seek to stand as far behind (or out of the way of) the PA system as you possibly can. The PA is not for you to hear the sound of your own voice. It is for your audience to hear you. The closer you stand to the PA loudspeakers, and the more you stand in front of them, the greater their apparent sound pressure is from the mic’s standpoint. This, of course, works against your voice being a very large signal when compared to other arrivals at the microphone.

This is another situation where sight lines may suffer a bit for some people. It depends on how the PA is deployed. As always, this is unfortunate, but your voice’s audibility must be the top priority. Your message will probably survive people not being able to see all of you at all times, but it may not survive people not being able to hear.

Acoustical Awareness

A sad fact of life is that many of our gathering spaces are built to hold many people while looking grand…and sound terrible while doing so. In the same way as musicians must be aware of how each player’s sound fits in with other sounds, so too do you have to be aware of your voice and the room. Intelligibility is key, and difficult acoustics ruin intelligibility. The sound of the room’s reverberation can easily “run over” and mask new sounds, even if it’s in a relatively subtle way. For intelligibility, you must have separation between the direct sound of your speech, and the indirect noise of previous sounds that are bouncing around the space.

To some degree, system tuning can help with this, but it’s just a “patch.” If a certain frequency area tends to build up, that area can be de-emphasized in the PA – but you have to be careful! Too much de-emphasis and it will be very obvious that a strange-sounding audio system is firing into a reverberant room. It is simply impossible to equalize one’s way completely out of an acoustical problem. Also, simply adding volume to the sound system doesn’t really help either. The audio system is a sonic emitter in the room, just like any other, and as such the room reverberation is proportional to whatever the PA is doing. A louder PA just means louder reverberation, and also a PA that’s less sonically stable. (Remember: We want the lowest possible gain.)

If PA volume isn’t the answer, then you have only one other element to work with: Time.

In a reverberant room, you MUST slow down. You have to allow for the reverberant sound to die off so that the next sonic event (a word or sentence) is separated from all the garble. Slowing down means that you may have to condenser your presentation, or allow for extra time.

There are some volume adjustments that work, but they have to come from the way you talk. Try to add a bit of emphasis to the “hard” sounds in your speech. Hard sounds act as signposts regarding where words start and end, and are critical to people figuring out what you’ve said if some of the other information is lost. Enunciating those bits mean that they stick out from other sounds, which gives intelligibility a boost.

Of course, if you can, you should pick a space with excellent acoustics for spoken word. That is, a room with a very short reverb time and very low reverb level. The larger such a room is, the more expensive it tends to be – and that loops right back around to not scrimping on audio.


Why Audio Humans Get So Bent Out Of Shape When A Mic Is Cupped

We hate it because it sounds bad, causes feedback, and makes our job harder.

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.

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

I recently posted something on my personal Facebook feed. That something was this:

[myface]

A number of people found it funny.

When you really get down to it, though. It’s an “in joke.” The folks who get it have lived through a cupped-mic situation or two, and probably know why it’s a bad idea. For other folks, especially those who have been surprised by being chewed on by an irate sound-craftsperson, the whole thing might not make sense. Why would an audio human get so irritated about how a performer holds a mic? Why is it such a big deal? Why are jokes about mics being cupped such a perennial feature of live-sound forums?

The short answer is that cupped mics sound awful and tend to be feedback monsters. The long answer has to do with why.

The Physics Of How Looking Cool Sounds Bad

Microphones are curious creatures. It might sound counter-intuitive, but creating an omnidirectional mic (a mic that has essentially equal sensitivity at all angles around the element) is actually quite simple. Seal the element in a container that’s closed at the back and sides, and…there you go. Your mic is omni.

Making a directional mic is rather more involved. Directional mics require that the element NOT be housed in a box that’s sealed at the back and sides. Sound actually has to be able to arrive at the rear of the diaphragm, and it has to arrive at such a time that the combination of front and rear pressures causes cancellation. Getting this all to work, and work in a way that sounds decent, is a bear of a problem. It’s such a bear of a problem that you can’t even count on a microphone patent to tell you how it’s done. The details are kept secret – at least, if you’re asking a company like Shure.

But, anyway, the point is that a directional mic is directional because sound can reach the rear of the element. Close off the porting which allows this to happen, and the mic suddenly becomes much more omnidirectional than it was just moments before. Wrapping a hand around the head of the mic is a very efficient way of preventing certain sounds from reaching the back of the capsule, and thus, it’s a very quick way to cause a number of problems.

Feedback

Fighting feedback meaningfully requires that mics be as directional as is practical. The more “screamin’ loud” the monitors and FOH have to get, the more important that directionality becomes. When setting up the show, an audio human inevitably finds a workable equilibrium ratio of gain to feedback. A highly directional mic has much lower gain in the non-sensitive directions than in the sensitive ones. This allows the sound tech to apply more gain in downstream stages (mic pres, monitor sends, FOH faders), as long as those devices result in output that the mic experiences in the “lower-gain detection arc.” At some point, a solution is arrived at – but that solution’s validity requires the gain of all devices to remain the same.

When a mic is cupped such that it becomes more omnidirectional, the established equilibrium is upset. The existing solution is invalidated, because the effective gain of the microphone itself suddenly increases. For instance, a microphone that had a gain of -10 dB at 2 kHz at 180 degrees (degrees from the mic’s front) might now have a gain of -3 dB at 2 kHz at 180 degrees. Although what I’m talking about is frequency specific, the overall result really is not fundamentally different from me reaching up to the mic-pre and adding 7 dB of gain.

Especially for a high-gain show, where the established equilibrium is already hovering close to disaster, cupping the mic will probably push us off the cliff.

Awful Tone

Intentionally omnidirectional mics can be made to sound very natural and uncolored. They don’t rely on resonance tricks to work, so very smooth and extended response is entirely achievable with due care.

Problems arise, however, when a mic becomes unintentionally omnidirectional. Directional mics are carefully tuned – intentionally “colored” – so that the resulting output is pleasant and useful for certain applications. The coloration can even be engineered so that the response is quite flat…as long as the mic element receives sound from the rear in the intended way. Much like the feedback problem I described earlier, the whole thing is a carefully crafted solution that requires the system parameters to remain in their predicted state.

A cupped microphone has its intended tuning disrupted. The mic system’s own resonant solution (which is now invalid), coupled with the resonant chamber formed by the hand around the mic, results in output which is band-limited and “peaky.” Low-frequency information tends to get lost, and the midrange can develop severe “honk” or “quack,” depending on how things shake out. At the high volumes associated with live shows, these narrow peaks of frequencies can range from merely annoying to downright painful. Vocal intelligibility can be wrecked like a ship that’s been dashed on the rocky shores of Maine.

An added bit of irony is that plenty of folks who cup microphones want a rich, powerful vocal sound…and what they end up with is something that resembles the tone of a dollar store clock-radio.

Reduced Output In Severe Cases

The worst-case scenario is when a mic is held so that the ports are obstructed, and the frontside path is ALSO obstructed. This occurs when the person using the mic wraps their whole hand around the grill, and then puts their thumb in the way of their mouth. Along with everything described above, the intervening thumb absorbs enough high-frequency content to make the mic noticeably quieter at frequencies helpful for intelligibility.

So the mic sounds bad, the singer can’t hear it, the whole mess is ready to feedback, the singer wants more monitor, and FOH needs more level.

Lovely.

I think you can see why sound techs get so riled by mic-cuppers. Holding a mic that way is fine if the whole performance is a pantomime. In other situations, though, it’s just bad.


Building A Small System

A guide to building a simple live-sound rig, from input to output.

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.

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

Every once in a while, I get a request for information on how to create or add-on to a system for live audio. I like to personalize this information, because rigs for show and event production are best built for specific applications. However, there is a point where insisting that everything be approached in a customized way becomes inefficient – a lot of the same ground gets covered repeatedly.

So…

If you’re wondering what I think is required for a “small, basic, but still worthwhile” audio rig, read on. I’ll be including lots of links to vendor pages where you can buy various products.

(We’re going to go in order of signal flow, by the way.)

Input Transducers and Interfaces

For the smallest possible rig, take a distributed approach: With anything other than vocals, have the musician supply their own, personalized sound. Further, seek to avoid the whole issue of putting the output of that sound through the PA. Let a guitar amp make the guitar sound, let the drums just make their own noise in the room, and so on.

Having the ability to put more in the PA increases your potential control over the sound of the show, but outside factors can prevent that potential control from becoming actual control. Also, more inputs means more complexity, and thus more difficulty in system operation. There’s no hard and fast rule of what to be ready to reinforce, but I generally encourage folks – especially folks new to this whole thing – to ease themselves into the maelstrom that is live audio.

Wired Microphones

A decent mic will basically sound like the thing it’s being pointed at. For this reason, don’t agonize about getting specialized mics for everything right off the bat. A good “vocal” mic will be fine for many, many instrument applications. I recommend buying mics with tighter patterns (super or hypercardioid), as they can make the handling of high-gain situations much easier. Tight-pattern mics do require that the musicians – especially the vocalists – be able to use them appropriately. This issue should be considered as something for the musicians to figure out, because no system can fix everything (and a basic rig can fix even less of everything, if you take my meaning).

My current favorite mic is the EV ND767a. You might also consider the Audix OM2. Here’s a comparison of the two at Sweetwater.

Microphone Accessories

Each mic you buy will require an appropriate stand and XLR-Female to XLR-male cable.

Budget stands (like these from OnStage Stands) are just fine… if you can put in the effort to be nice to them. Gator Frameworks also has some promising offerings.

When it comes to cable, don’t overspend and don’t oversave. For a 20+ foot mic cable, paying more than $1.00 per foot is a huge premium for no benefit that I’ve been able to clearly observe. There are perfectly decent cables that can be had for as low as $0.40 per foot when purchased in a bundle. Going much below that, though, is likely to lead to problems.

I’ve been quite happy with cables I’ve gotten from Audiopile and Orange County Speaker. I’ve gotten some REALLY inexpensive cables from Unique Squared that were okay for a good while, but started having problems after a number of uses.

Wireless Mics

One word: Don’t.

Wireless is a pain in the donkey, with the FCC selling off all kinds of UHF spectrum to cellphone and computing companies, and the frequencies used for digital wireless becoming ever more crowded and hostile. Functionally, wireless transmission of audio is far more “fragile” than signal running on a cable, with all kinds of weird things that can happen outside your control.

But no matter what I say, you’re going to buy at least one wireless mic anyway, so…

Buy a digital system that operates in the 2.4 Ghz band if you want a chance at retaining your sanity in the short term. Specifically, look at the XD-V55 systems by Line 6. They’re very reasonably priced, have nice features like remote monitoring of mute status and battery level, and are the best wireless experience I’ve personally had to date.

You can, of course, go up from there.

Wireless Mic Accessories

Handheld wireless mics benefit greatly from having a stand available for every transmitter. Further, each receiver will need a cable to interface with the rest of the system.

Direct Boxes

A direct box is what I class as an “interface,” because it doesn’t convert acoustical events into electrical signals. A DI makes signals that are already electrical play nicely with pro-audio equipment when they might not otherwise. An aspect of this is also isolation, in that the DI creates what you might call an indirect connection between a console and a device. This can be very handy if the sending device (a guitar, keyboard, sampler, whatever) can’t tolerate phantom power, and the console has phantom applied to the signal line in question.

Direct boxes come in two main flavors, passive and active. Active DI boxes require external power of some kind, be that power from the wall, batteries, or phantom from the console. If you’re going to buy DI boxes, buy ACTIVE models. An active DI will work with almost anything, whereas some instrument pickups pair quite badly with passive boxes. You might as well buy units that work everywhere, and thus simplify your life. Expensive models from BSS, Radial, and Countryman are certainly nice, but there’s great value to be had in units from ART and Behringer, especially the “multiple modules in one box” offerings.

DI Box Accessories

Just like a microphone, each DI box will require an XLR-Female to XLR-Male cable. Remember that multi-module DI boxes require a cable for each individual module.

You don’t have to actually mount a rackable DI system, but you might want to. Sweetwater and Audiopile both sell quality rack cases in a huge variety of configurations.

Snakes/ Multicore Connections

Depending upon how you implement the mix and signal processing part of the rig, you may or may not require multicore cabling. If you want to send and receive a bunch of audio signals at a remote location, a snake really is a must. If you merely want to control the processing of signals from a remote location, you might be able to use your console in the same way you would use a traditional snakehead or stagebox.

If you do use a multicore, I suggest getting one that’s a little “overkill” in terms of the number of lines it contains. If a line fails, you’ll have a spare to patch to. “Headless or “fan-to-fan” snakes are a bit cheaper, but less convenient than multicores that terminate one end at a box. (You will always have to hunt for the specific line you want to connect to. It’s like a law of nature, or something.)

Audiopile would be my first choice for buying a snake I was really serious about. I have had good results with Seismic Audio fantail-to-fantail snakes, but my experience with their stagebox offerings has been mixed.

Mixing Consoles and Output Processing

This is where things get REALLY interesting.

Essentially, you have three major choices:

1) Use a relatively simple console where output processing is handled externally, and place all that at a “remote” location.

2) Use a more sophisticated console that encapsulates the output processing, and place the console at a “remote” location.

3) Use a more sophisticated console that encapsulates the output processing, leave the console close to the stage, and control the console from a remote location.

Option one takes up more space and requires more complicated physical patching, but the interface can be easier to understand at an intuitive level. Option two is compact and easy to physically patch, but the whole thing can be less intuitive for an inexperienced operator. Option three is like option two, with the added issue that control can depend entirely on an external device and network connection. If those fail, you may be in big trouble.

In every case, a console with some room to grow in terms of both inputs and outputs is a good idea. Don’t go overboard, though. You’ll end up spending a lot of money to no functional end. Especially if you’re new to all this, keep your monitor sends down to a maximum of four.

Option 1

The Console

Whatever you do, buy a console where the EQ has sweepable mids on the EQ and pre-fader auxiliary sends for each unique monitor mix you want to handle. A Soundcraft EPM8 is probably the minimum you should look for. I’ve been quite pleased with Yamaha’s mid-basic offerings, which have been revamped since I’ve bought one.

Simple, analog consoles “race” in a VERY tight pack, which means that there are lots of little permutations and many viable choices. Mackie, A&H, and Peavey are all worth looking at, and Behringer, while not having the shiniest reputation, has a knack for cramming lots of features into small cost. An XL2400 has what I would consider to be pretty darn flexible routing for a $650 mixer.

Console Accessories

Some consoles can be easily cased up or rackmounted, and some can’t.

You will need patch cables and/ or adapters with appropriate ends to get from your console outputs to your processing, one cable for each channel. As with other cables, high-dollar options really aren’t necessary. Stay somewhere in the $2/ foot range, and you’ll have patch connections that are long enough for some wiggle room and cheap enough that you won’t cry about ’em.

Also, get yourself a decent set of headphones for listening to the console’s solo bus. I have a pair of very-well-loved HD280s, and lots of other options exist. You want to look for closed-back, durable, “un-hyped” phones if you’re doing your own hunting.

The Processing

What you choose for output processing depends greatly on your own personal taste and comfort level. At the minimum, you should have an independent EQ for each mix. A really basic setup might be three mixes – one for the audience, and two monitor mixes for the stage. Things go up from there, of course.

Graphic equalizers, while not my personal favorite, are straightforward for most folks to operate. I generally recommend 31-band models over 15-band units, because you can focus in on a problem area without sledgehammering material that’s not making trouble. Peavey and dBX are good overall bets, but affordable graphics are similar to affordable consoles: All the players are very similar. I do like the features of the Behringer FBQ3102, but I also had one die after a year of use and a bumpy ride in the back of a truck.

If I’m going for an EQ-only solution, I can tell you that I vastly prefer a flexible parametric EQ over a graphic. In that realm, I have been extremely impressed by Behringer’s Feedback Destroyers. To be clear, my experience is that their automated feedback management is mediocre at best – but they are WICKED HANDY when you run them manually. You get a huge number of fully parametric filters at a very low price point. I’ve never had a major problem with any Feedback Destroyer I’ve owned. (Be aware that parametric EQ is more involved than graphic EQ. It’s not quite as “grab-n-go.” There are more choices that you have to make deliberately.)

If you want your processing to include dynamics, and also to let you have a graphic EQ combined with a parametric EQ, then a Behringer DEQ2496 is another killer device. Again, I haven’t found anything else exactly like it “in the wild,” although a Driverack PA2 is actually very close. DEQ2496 units do sometimes have problems with one of the internal connectors getting loose, but it’s an easy fix once you get the cover pulled off the device…and the connector freed from being glued down. (You will very definitely void your warranty if it’s still in effect, but hey, live a little.)

Processing Accessories

You may or may not be able to patch your snake returns (or other output cables) directly to your processing, so some adapters or patch cables might be necessary.

Also, you should definitely rack up any outboard processors you have for your system. It really does help to keep things neat and tidy.

Option 2

The Console

Digital consoles are a great route to take if you want to keep everything in one box. The downside, of course, is that the one box becomes a single point of failure. Then again, in any case, losing the console pretty much ends your day if you don’t have a spare.

Another factor to consider is that the processing available in digital consoles tends to be more fully featured while also being somewhat abstracted. This can make them overwhelming for new users, who simply don’t know what to make of all the options available.

If you’re going to be physically present at the console, you may as well get one that has a control-surface integrated in some way. An X32 Producer is a pretty natural choice, along with offerings from Presonus, Allen & Heath, and QSC.

Console Accessories

As was said earlier, rackmounting or casing the console might be possible. You can decide if you want to go to the expense or not.

The need to buy patch cables or adapters may still be there, depending on the configuration of your snake or other output lines.

And you’ll still want some headphones.

Option 3

The Console

You can leave the console on stage and mix remotely with the consoles detailed above, although the control surface might be a bit of a waste. Affordable digi-mixers that lack a surface are an interesting new product on the scene – just remember to factor in the cost of a remote-control laptop or tablet. Also, be aware that remote control is inherently a bit more “shaky” than being physically present at the mixer. It’s not horribly problematic, of course, but you have to have a contingency plan.

Surfaceless consoles at lower price points are available from Behringer, Soundcraft, and A&H. More expensive units also exist, of course.

Console Accessories

Surfaceless consoles are definitely rackable, and definitely should be.

Remember to buy the necessary patch cables or adapters for the outputs.

…but you can probably skip the headphones, because the consoles don’t currently stream the solo bus to a remote location (that I know of). That’s another downside of the number three option – to access the solo bus, you still have to be physically present at the console’s location.

Output Transducers (Speakers, That Is)

You’ll notice that I didn’t include an option for amps and passive speakers, and there’s a reason for that: This is supposed to be a simple system, and powered speakers are really the way to go to achieve simple.

Also in the service of simple is to keep your monitor wedges and FOH speakers interchangeable. Unless it’s completely inappropriate for your application, having loudspeakers that are all of the same model means that you can expect similar behavior from each box. If a failure occurs, you can swap one box for another and not have to think about it too much.

When buying powered loudspeakers, accept nothing less than an honest-to-goodness, biamped, fully processed unit. There are plenty of powered speakers that are single amped, with no processing outside of a passive crossover that is placed between the amplifier and the drivers. You want something more – something with an active crossover, basic corrective EQ applied at the factory, and an internal limiter. A peak SPL rating of greater than 120 dB @ 1 meter is also a good thing to look for, even with all the “fudging” that marketing departments apply to output numbers.

In terms of specific recommendations, I can say that PVXP12s have done very well for me. I can do “rock and roll” monitors with them in a small space, and I’m confident that they would perform equally well as an FOH unit. There are lots of other possibilities of course, provided by JBL, Mackie, Yamaha, and Behringer (just to name a few).

Loudspeaker Add-Ons

First, make sure you have the necessary cables to get from the console or snake outputs to the loudspeakers. Because speakers tend to be deployed in a rather spread-out fashion, it’s advisable to buy a bit more cable than you think you need. A 50 footer for each loudspeaker is probably a good start.

When it comes to stands for your FOH speakers, it’s good to get something a little nicer. Stands with locking collars and/ or piston assists can be a big help. I’ve used crank stands in the past, and they’re okay, but given a chance I’d make the upgrade to a more technologically advanced support.

The Biggest Accessories Of All

In the end, none of the fancy gear will mean much without power. You don’t have to buy really fancy power-conditioning equipment, but some rackmountable power units help reduce the need to fish around for a bunch of “free range” power taps. Of course, you should still keep a few freely-positionable power taps handy, along with several extension cords that use 14-gauge conductors (or something beefier, like 12-gauge). Powered speakers spread out all over creation have an alarming tendency to need those extension cords.


While there are other sundries and gadgets you can add on, going through the above should get you a working rig. As I said, this is a basic system. It won’t do everything for everybody all the time, but it should provide you with a decent start.