Guide to Buying Pro-Audio Equipment

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MUSIC SHOP MYTHS

By Ben McFarlane
Oct 1, 2006

The pro-audio industry is highly competitive on a global scale. Prices are constantly dropping. New products hit the market in a steady stream, and they are all—according to their makers and sellers—magnificent. That can make it difficult to choose the right gear. The difficulty is compounded by many misconceptions and inconsistent industry language. A regular set of these recurring problems and headaches often gets in the way of smooth, problem-free recording and stage performance. This rough guide to buying pro-audio gear covers everything from microphone to mixdown.

When you’re in the market for new gear, the devil is in the details. Knowing those details before they sabotage your setup will save you a lot of pain and suffering. Asking the right questions also will flatten a lot of wrinkles in your product search. So if you’re ready to buy but are nervous about getting stuck with a lemon, then arm yourself with this knowledge and choose wisely.

CONDENSER MICROPHONES
Key questions: Does it have a high output?

Does it have low self-noise?

What does the frequency response look like?

Do I need a bass rolloff?

Do I need switchable polar patterns?

The audio signal chain begins with an input device, which can be a transducer pickup, a keyboard or a turntable, but most often it is a microphone. If you’re recording, a condenser mic is usually best; if you’re performing live, a dynamic microphone is the way to go. Most microphone confusion concerns condensers.

Choosing a condenser mic is difficult because there are so many of them. With microphones, like all products, the cheap ones make sellers more money than expensive models because of higher sales volume and profit margins. You can buy a condenser for around $50, which is low compared with the mics everybody talks about. Most people will say they pay more money for “warmth,” a term that people throw around a lot. If you spend more, you get a warmer mic; but the term “warmer” is vague.

A bass-playing uncle once described warmth to me like this: Solid-state or transistor guitar amplifiers distort harshly at high frequencies, whereas tube amplifiers typically distort at low frequencies, creating the characteristic bottom-end distortion musicians refer to as warmth. For quite a while, many music-industry professionals comfortably considered the function of tubes (as opposed to other amplifier circuitry such as transistors) to be the addition of warmth. That is a ubiquitous misconception. A producer later reiterated my uncle’s explanation, saying, “Warmth refers to low-frequency harmonic distortion, like what you would hear in an overdriven tube guitar amplifier. It does not refer to the quality of a mic or preamp.” A mic that adds any harmonic distortion is not desirable.

Chances are, if someone calls a mic warm, they’re not saying it distorts at low frequencies; it probably doesn’t. More likely, either they know it is a tube mic and therefore think of it as a warmer mic, or they’ve heard it and think it is clear and smooth-sounding with lots of low-mid saturation and a clean treble response. The latter is typically what people mean when they refer to warmth in a recording environment. Thus, don’t buy a mic or a preamp just because it has a tube or because it is “warm,” “punchy” or “fat.” These general descriptors are overused; they mean less than you might think.

If you’re willing to pay a bit extra for a microphone, focus on particulars and keep your recording environment in mind. Both tube or transistor circuitry in a microphone will help the output. With either component type, if the circuitry is well-designed, you’ll have good output and low noise. That’s what you want. If you’re buying your first mic, stick with something that has a wide frequency coverage to accommodate a range of instruments. A large diaphragm condenser with a switchable pattern usually fits the bill. The Apex460 (www.apexelectronics.com) is extremely versatile for its price of $350. If you’re recording in the city, even if you can find a quiet spot, you’ll most likely have to contend with low frequencies of traffic or machine noise coming through the walls of your house or apartment. For that, many inexpensive mics come with a bass roll-off filter to get rid of undesired low-frequency noise.

DYNAMIC MICROPHONES
Key questions: How high is the gain before feedback?

How is the handling noise?

What does the frequency response look like?

What is the polar pattern, and will it suit your needs?

For live performance, dynamic mics handle feedback better because of their coil design but are also less sensitive than condenser microphones. Microphones that will be handled during a performance should have low handling noise. That often means that the microphone has an internal shockmount system such as the Shure SM58 ($188; www.shure.com). The other main virtue of a dynamic microphone is the amount of gain it can handle before feeding back. If you can crank it without it squealing, you can give vocals the center stage in a big live mix.

MIXERS
Key questions: How are the preamps?

How many channels versus channel strips?

Is it noisy?

Is there flexible routing?

The next stop in the signal chain is the preamplifier. That can be a solitary piece of hardware or a component of a mixer. The preamp’s function is to add gain to the signal while adding as little noise as possible. Since they’re the main source of noise for mixers, companies try hard to make preamps as quiet as possible. The mic preamp typically corresponds to the mixer’s XLR inputs, and you usually see—printed beneath the XLR input—words to the effect of “really quiet mic preamp.” Compact Yamaha boards (www.yamaha.com/ca) have “ultralow noise” preamps, Behringer’s (www.behringer.com) are “transparent” and the new Mackie Onyx boards (www.mackie.com/onyx) allegedly have the best preamps out there. Can it be that all mixers have noiseless preamps?

The real test of a preamplifier’s noise level is 40 or 50 dB of gain. Since mics are too quiet to take advantage of a signal’s full potential gain, you need to wind up the gain on your mixer or stand-alone preamp. Doing that amplifies both the signal and the noise. That will show you how the preamp performs at levels you’re likely to feed it. Mackie designed the Onyx preamps to exhibit no noise even at higher gain levels, and—by all accounts—they succeed. The Onyx preamps are also better at rejecting radio-frequency interference and have superior dynamic range (although some pros claim that they don’t fill out the low end like nice outboard preamps).

When considering the number of mixer channels, you’ll want to see photographs or the actual hardware. Pro-audio customers may be interested in a 16-channel board, but then they find out that it doesn’t have 16 XLR inputs or 16 channel strips as they had assumed. That is more of an inconvenience than a real problem; the number of channels, however, frequently does not correspond with the number of channel strips or XLR inputs. For example, the Yamaha MG12/4 ($239), advertised as a 12-channel board, has only 8 channel strips and 6 XLR inputs, but its 4 stereo channels brings the total channel count to 16. Always check or ask about that.

RECORDING INTERFACES
Key questions: Does the number of inputs match the number of channels into the computer, or is it mixed to stereo?

Do all of the inputs record independently?

Is there phantom power for a condenser mic?

Are there preamplifiers?

A recording device is the next step in the signal chain. Mixer and computer recording interfaces are fast becoming one. Before long, all mixers may be compatible with a computer via FireWire or USB. The Mackie Onyx, Yamaha MW and Alesis Multimix (www.alesis.com) series are current examples. In many cases these mixers are only marginally more expensive than their interfaceless counterparts.

Digital audio is divided into bits and kilohertz. The audio can be 16- or 24-bit and, usually, 44.1, 48 or 96 kHz. It’s convenient to be able to switch between resolutions depending on what you’re doing. If you have lots of room in your hard drive, record at 24/96. If your interface supports only 24/48, then you’re still in pretty good shape; but for the difference in price, the small disparity in fidelity is worth it.

A common mistake with interfaces is equating the number of inputs with the number of independently recorded channels. Often the separate channels are mixed to stereo before entering the computer. If you have a 12-input mixer or interface that connects via USB 1.1, then you probably just have one stereo channel going to the computer. Contrary to what some believe, latency doesn’t come from having too little bandwidth. USB 1.1 can handle only a few audio channels; USB 2.0 has 40 times more throughput, so it—as well as FireWire—can handle whatever you throw at it. Latency is almost always a driver problem, often due to the failure to switch from Windows MME drivers to the ASIO drivers that correspond to the audio interface. The bottom line is if you want to separate your mix in your software, go with USB 2.0 or FireWire. You must accept that all interfaces are going to have at least some latency, even if it is negligible.

Finally, don’t assume that an interface is going to support a mic input. Some interfaces, such as the Behringer FCA202 ($100), are designed specifically for connecting preamped sources to a computer. Those will not handle direct connections of mics or guitars to the computer.

LOUDSPEAKERS AND POWER AMPS
Key questions: Is the advertised wattage RMS or peak?

How is the distortion at high sound-pressure levels?

Does the speaker cabinet resonate and interfere with the sound?

Is the amplifier wattage measured at 2, 4, or 8 ohms?

Loudspeakers are often advertised at their “peak” wattage values, which is how great a power spike the speaker can handle before it shuts down permanently. Peak power is almost always twice the RMS (continuous power), which is what you should use to judge a speaker’s capability. If a speaker is advertised at 400W, it may mean RMS or peak. If you’re comparing prices, and you notice substantial differences with similar advertised power ratings, it could be that one company is referring to peak power and one is referring to RMS. Since RMS best represents a speaker’s performance, ask for the RMS rating of a speaker. Also ask about transparency and distortion at high sound-pressure levels.

Different companies refer to the power rating of their amplifiers at different levels of impedance. For example, a Behringer EP2500 ($489) appears to be approximately the same wattage as a Yamaha P7000S ($969). They are advertised at 1,200W per side and 1,100W per side, respectively. Behringer’s output power is measured at 2 ohms, however, and the Yamaha is measured at 4 ohms. At 2 ohms, the Yamaha is 1,600W per side: a more powerful amplifier. The price is proportional, and both companies are being honest, but it gives you a reason to check the specs and make your decision from those rather than from what you’re being told.

STUDIO MONITORS
Key questions: How does the frequency response look?

Are there controls for room resonance?

What is the frequency range?

With studio monitors, a flat frequency response is necessary. It is also nice, however, to have comprehensive frequency coverage as well. A monitor that covers 30 to 20,000 Hz is all you’ll ever really need. That said, even a monitor that goes down to only 70 Hz will serve the purposes of most amateur producers.

Where it gets more complicated is how the speaker interacts with the acoustic space. You will see controls on the back of monitors such as the M-Audio BX series speakers (www.m-audio.com) or the ever-popular Behringer Truth series. If you have a subwoofer or a monitor that covers lots of bass range, you must pay special attention to speaker placement. Because of room resonance, some bass frequencies can be tremendous and some can get completely lost. For more information on this topic, you can research the Rayleigh equation and experiment with speaker placement.

MULTITRACK RECORDERS
Key questions: Do I need a CD burner?

Is there enough memory for a full, uncompressed studio recording?

The alternative to the mixer/interface/digital audio workstation (DAW) is the digital multitrack recorder. This group of device is the replacement for the analog 4-track or 8-track. Most people want multitrack recorders because they don’t own a computer or don’t want to deal with computer-based DAWs. Some multitracks come with their own high-capacity hard drives, and some rely mainly on compact memory such as Smart Media or CompactFlash cards. A few words of caution: The smaller, card-based multitracks often don’t come with enough capacity to record an uncompressed file. Generally, it is best to record plain WAV files, since they’re uncompressed and of the highest possible quality. If you want to record uncompressed files, you should buy something with its own hard drive. If you don’t own a CD burner, having one on your multitrack is extremely convenient.

HARDWARE AND SOFTWARE EFFECTS
Key questions: Do I have enough CPU power to rely on software effects? Do I want to spend oodles on analog gear?

Do I want to spend oodles on analog gear?

Effects can come from three places: the mixing board, computer or external hardware module routed through the mixer or interface. Many people believe that hardware effect modules sound better than software effects, but such is not always the case. Digital effects, whether they come from software or from hardware, can be fantastic.

There are a few ways you’re limiting your setup if you rely exclusively on software effects. The first is that you preclude any analog effects that hardware effect modules can provide, although high-quality analog effectors are always more expensive. By relying entirely on software effects, you will also put more strain on your CPU, especially if you’re using a particularly meaty effect like a convolution reverb. A good medium-priced digital hardware effect module like the Lexicon MX200 will make things much easier on your computer if you’re having trouble this way. Just make sure you have the right inputs in your setup.

One advantage to software effects is that the settings are always saved in whatever project you’re working on. With hardware effect units, you’ll have to save your settings in the user presets and load them manually each time you switch projects. If you’re going to rely on hardware, hopefully you’re focused and can start what you finish before starting something else. Strictly in terms of diversity and flexibility, software effect plug-ins are great. If you don’t know whether you want something, you can try it in your setup before buying it.

PRO-AUDIO PITFALLS
In this game, sometimes you have to take precautions so that you reduce your chances of buying a defective product, receiving bad customer service or falling into a pond full of alligators (oops, wrong game). A big problem area for some companies is customer service. Many have bad service or consistently malfunctioning products—sometimes both. Two years ago, a run of mixers continuously returned to my pro-audio department with a broken XLR input. Luckily, the company in question offered fantastic service. On the other hand, some companies seldom have equipment problems but suck at servicing them when they do. Always ask the retailer about a manufacturer’s service record.

Another big hazard comes from competition. Every company does independent research and development, and there is a convergent evolution of similar products at similar prices and times. Sometimes Product A costs a retailer as much as Product B to sell to a customer. For example, a recent portable PA system offered a nice package, but was fairly powerless at 75W per side. Then the Yamaha Stagepas 300 ($699) —150W per side—dropped to a lower price. The only option for dealers was to sell the other PA system at cost. Because of that, you should always survey the entire field or products whenever you’re buying. Sometimes you’re not getting the best deal simply because someone along the line (either the supplier or dealer) has paid more than they should have for the product and doesn’t want to price it to compete with something that is better or equal.

Special orders are also perpetual headaches. If you special order something not in stock at a retailer, it has to come from the supplier, who may not have it in stock. In this case, the product has to come from the manufacturer, which can take months. To avoid that, ask whomever you place the order with to find out if it is in stock at the supplier or when the supplier expects it to arrive. Sometimes there’s a specific arrival date, and sometimes the supplier doesn’t know. Asking that in advance may lead you to buy the product from another source.

If you apply the information learned from this article, you’ll avoid the most common problems that occur when buying gear for home recording or gigging and help separate an educated retailer from an uneducated one. Ideally, a salesperson should have researched these questions already, but at the very least, she or he should be able to find answers for you. Now that you know what to watch for, have fun looking.

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