Finding the Right Microphone for Your Customer by George Petersen

The Shure SM58 has been in production for nearly half a century

Over the past decade or so, the industry has experienced an absolute explosion in the number of microphones available, in every type, ranging from ultra low-end “three for $29.99” handhelds to exotic high-end models from boutique suppliers costing thousands of dollars. Between those extremes is every type imaginable, yet somewhere out there is the perfect choice for your customer and it’s often up to you to steer the buyer to the right model. 

Oddly enough, selecting a microphone is not too far removed from the process buying a car. Automatically steering a walk-in customer to the red convertible in the front row might make your boss happy, but is that really the right vehicle for that buyer, who may be looking for a minivan, SUV, pickup truck, or a gas-saving subcompact? Each type of vehicle has a certain appeal to different customers and it’s up to you or your sales staff to determine exactly what that need is before you can recommend any particular model. And the same approach applies to microphone sales.

As with most sales, a little communication with the customer is vital and starts with a simple question. “What do you need this microphone for?”

Selling a trumpet may come down to choosing a model from the proverbial “good/better/best” selection, but microphones are complex and are linked to a need to match the mic to the type of gear the customer has. For example, one of the best-selling microphones of all time is the venerable Shure SM58, which has been in production for nearly half a century. But if a customer walks in and is looking for a replacement mic for their inexpensive home karaoke system, what they probably need is a blister-packed model with an attached cable that ends in a 1/4-inch or 1/8-inch plug.

However, if you continue the conversation and also find out that the customer’s daughter also plays in a band and would like a mic that could double for both purposes, then perhaps that SM58 might be a good choice, as long as you also included an XLR-to-1/4-inch impedance adapter as part of the sale. It may seem obvious, but here’s a good example where listening to the customer’s needs makes sense — and cents. 

Understanding Microphone Types

Before we get too far out, let’s back up with some basics about microphones. By understanding a few simple facts about microphones, you’ll be better equipped to deal with solving the mystery of finding the right mic for your customer. So bear with me while we delve into a bit of “Microphone 101.”

There are two common categories of microphones used in professional audio. Dynamic microphones operate when sound waves strike a diaphragm attached to a coil of wire. When that coil moves within the magnetic structure of the microphone, this creates an output voltage. The process is exactly the reverse of the way a speaker operates. One less-common encountered variation of the dynamic approach is the ribbon mic, which uses a thin ribbon of metal that is placed between the poles of a magnet. Most ribbon mics are bidirectional, meaning they pick sounds equally well from either side of the mic.

Condenser microphones use an electrically charged, metallized diaphragm, which is placed very close to a conductive back plate and separated by a thin air layer. Sound waves striking the diaphragm cause a very small voltage change, which is increased by a tiny amplifier circuit within the mic body. As power is required by both the microphone capsule and the amplifier, condenser microphones must have a power source, which can be a battery inside the mic body or “phantom” power coming from either the mixing console or an external power supply.

Dynamic microphones tend to be extremely rugged, making them especially well suited for most live sound applications – instrumental and vocal. However, the extremely thin, low mass diaphragms used in condenser microphones provide improved high-frequency response, with better reproduction of fast transient signals for more detail. Therefore, besides vocals, condenser microphones are usually preferred for reproducing instruments such as piano, cymbals, and stringed instruments.

It’s also important to note that microphones come in all sorts of shapes and sizes and two microphones – such as the AKG C5 (condenser) and D5 (dynamic) models shown in Fig. 1 – are outwardly quite similar in appearance, even if they differ substantially “under the hood.”

A Definite Pattern

Another important technical detail to keep in mind is a microphone’s directional response (often referred to as its polar pattern). Mics exhibit a wide variety of degrees of directivity. Ultra-directional “shotgun” models (frequently used for broadcast or video “production,” reject sounds from entering the side of the mic body, with the greatest sensitivity to sounds directly in front of the mic. Other mics may be omnidirectional, which pick up sounds equally coming from every direction. Omni models can be problematic as they are more prone to feedback when used in a P.A. system and, in an onstage application, may pick up as many unwanted sounds – like audio “leakage” from a drum set or loud guitar amp – as the soft spoken vocal you’re trying to capture. Some studio mics – and a few models designed for live sound – are equipped with a pattern switch that lets the user select from a number of polar pickup patterns, but the majority of microphones use some variant of the directional cardioid response.

Versatile and the simplest to use, cardioid mics (and their hypercardioid cousins) are probably the most common directional patterns among all microphones. Cardioid models (the name comes from the pattern’s roughly heart shape) are most sensitive to sound sources directly in front of the mic and a have a deep “null” point behind the mic, where the mic’s sensitivity is greatly reduced. When a cardioid mic is used with an onstage floor monitor, that speaker should be placed 180° directly behind the mic for best results. Conversely, a hypercardioid model has two null points (each 120° behind the mic), so these operate best with a floor monitor(s) that are slightly off to the side of the performer.

Concerning all these variations, it should be noted that cardioid or omni designs can exist with either dynamic or condenser models. 

And, anyone who plans to use a condenser mic needs to understand a few caveats. Other than a few models of mics that have an onboard battery to power the condenser electronics, the 48-volt phantom powering scheme used by most condenser mics may not be available on simpler lower-end mixers or P.A. heads. So if you want to have a “universal” mic that works with nearly any P.A., you may want to stick with a dynamic model. Another issue with condenser microphones is that the user must make sure that the channel and master volume levels on their system are turned all the way down while these are being connected and powered-up. Otherwise, a loud, nasty “pop” blast roars through the system and can damage the mic, your mixer, and your speakers.  

Beyond the Specs

This is all well and good, but why do I need to know any of this? Understanding a few basics can help you find the right microphone for your customer.

As an example, let’s consider the common scenario of someone who walks into your store and wants to buy a handheld microphone for live performance. Without sounding too much like a pushy used car salesman, it might be nice for you – the retail employee – to make a few pre-sale queries and try to figure our what to recommend. Let’s say the buyer walks in asking for “the best microphone you have.” Before you start pulling out that folder of brochures from pricey, esoteric manufacturers who offer drop-ship service of a $4,000 model that few stores keep in stock, it might be best to ask that person a few questions. Some customers may not realize that some microphones can cost hundreds or even thousands of dollars and knowing each microphone’s intended use is critical to figuring out what they really need.

Sometimes, price is an entirely different issue. As someone who does a lot of studio and live audio – both as a performer and an engineer – I own a lot of microphones. Some of these even fall into that very pricey, esoteric vacuum tube condenser category, along with other, less expensive solid-state condenser models, and a huge array of dynamic designs. Within this collection is nearly every type imaginable, from specialized large-diaphragm styles designed specifically for kick drums and bass amps, to compact vintage recreations for live handheld harmonica performance. Yet there’s a place for every mic in every budget, and even as someone who owns this formidable assortment that includes $4,000-plus models, I still have a need for some $29 editions, which are ideal to go out with loaner P.A.’s, or in that shared rehearsal space or for use when I’m forced to leave a system unattended for extended periods and I don’t want to lose sleep worrying about the mics.

As I said, there’s room in this world for every mic at every price. And sometimes the best way to bring up pricing with potential customers is to ask whether they have a budget in mind, rather than “how much do you want to spend?”

Determining the Customer’s Needs

The next step is simpler – determining how your potential customers plan to use a microphone (for example, recording, performance or perhaps both) and whether they need a handheld or stand-mounted model. Also, finding out what kind of gear your customer owns is an essential part of the process. The approach to a customer that understands mixers, preamplifiers, and recording is far removed from the way you deal with someone who wants a simple solution for easily recording some sounds or a podcast onto their Mac using GarageBand — or to a PC using Steinberg’s Cubase LE. For many of these customers, a mic with a USB output connection (such as the Blue Snowflake) may provide an easy-to-use yet decent-sounding introduction to the world of recording. 

It’s also important to emphasize that customers need to realize that a microphone is a personal “instrument” that’s equally if not more important to a performance as the quality of the guitars, keys, and drums in the band. I find it ironic that every day, lead singers go onstage holding a mic that costs less than the drummer’s hi-hat cymbals. If vocals are really important to a quality performance — which they definitely are — then some care is necessary in choosing the microphone to capture that performance. 

Different mic models that have nearly identical performance specs can sometimes sound quite different. Some mics may have a noticeable midrange presence boost that helps vocals (particularly male) “cut through” the mix. Cardioid microphones can also exhibit varying degrees of “proximity effect,” a phenomenon that exaggerates very low frequencies and bass tones when the vocalist is very close to the mic’s grille. This is great for some performers; less so for others and simply depends on the individual’s voice. Microphones are not a “one size fits all” proposition and spending some time to find the right “fit” of mic to voice can make a huge difference in vocal tone and quality.

Another factor is basic hygiene. A couple years ago, Audio-Technica created a created a brilliant and humorous public service YouTube video. called “Get Your Own Mic”  (youtube/CdxvVNIRiKs). This used an example of a very abused mic in a local club setting to emphasize why you just might want to invest in a microphone solely for one’s one use. Hey, you never know where that borrowed mic was the night before, so you have to be careful.