When new restaurants and bars plan their openings, they tend to put a great deal of focus on picking the right equipment and furniture for seating, kitchen and waiting areas. Unfortunately, AV equipment for background music, paging, intercoms and even television viewing is often relegated to the bottom of the to-do list. Sound design becomes an afterthought and budget-conscious owners opt to self-install consumer grade speakers where they think they look good or aren’t in the way. Over time though, many business owners learn that cutting corners with haphazardly placed, low-cost AV equipment can result in unreliable and inefficient performance.
There’s a common misconception that all TV’s, speakers, and amplifiers are alike, however, there are substantial differences between equipment manufactured for home and commercial use. Restaurants and bar owners might not consider that consumer goods are intended to be used only a few hours a day and typically come with a one-year warranty. They’re not built to sustain the wear and tear of multiple shifts, year-after-year. Professional AV equipment is ruggedized to withstand operation 12–16 hours a day and comes with warranties and support to protect purchases for extended periods of time.
Keeping It Cool
It’s not that powerful home speakers can’t project sound in professional environments; the problem resides primarily in other components of the audio system. To save costs, most home stereos are constructed with an amplifier and source selection in one unit. Usually, they are convection cooled, meaning there are no fans; just holes intended to dissipate heat.
Restaurant areas can be extremely hot and convection cooling isn’t effective enough to keep the amp from overheating and failing. Sometimes the most convenient place for equipment you don’t want customers to see is in the kitchen or high on a shelf above the cash register. Consumer electronics mounted in these hot, steamy, greasy areas are likely to prematurely fail. Professional amplifiers, like the CDi DriveCore Series, contain variable speed fans with sensors that adjust to fluctuating temperatures. When they get hot, the fans speed up to pull more air through the unit to cool the electronics. Convection cooling is often used in professional amplifiers in conjunction with the amplifier design to withstand sustained use. For example, the JBL CSA and JBL CSMA Series of commercial and mixer amplifiers additionally deploy DriveCore technology and run at lower temperatures than other convection cooled amplifiers.
Balanced Versus Unbalanced Lines
Another import difference between professional and consumer audio products is that consumer products use unbalanced external lines (positive and ground) while professional grade equipment uses balanced lines—positive, negative and ground—providing effective rejection of external noises such as radio frequencies, WiFi, cell phones, high voltage compressors and motors.
The issue with unbalanced wiring in consumer products is that the extended distances required in commercial establishments can turn the wiring into an antenna, attracting unwanted radio signals and putting noise into the system along with the audio signal. This often happens with cable or satellite TV sources placed in areas close to staff where they can easily use remotes to change channels. The audio signal wires from the TV receiver typically connect to a sound system mixer or amps in a different location and can cause electrical outlets, fluorescent ceiling lighting and other electrical elements to interfere with the signal.
It’s not just the external wiring that must be balanced to avoid interference. The circuitry within professional quality amplifiers and mixers must also include positive, negative and ground in their design. DIY owner-installers often don’t grasp the difference between balanced and unbalanced wiring, especially when they piece together a combination of consumer and professional equipment.
The output of consumer audio equipment is two channels (stereo) while professional equipment uses a mono output for consistent sound throughout a location. Putting an unbalanced stereo input into a mono balanced piece of equipment can result in the two channels canceling each other out and negatively impacting the audio quality. For professional use, equipment must be consistently balanced throughout the system.
Professional Level Sound Coverage
The key to good sound design is ensuring optimum music and/or paging coverage. Restaurant and bar owners who go to a consumer electronics big box store typically buy a stereo and mount it with a pair of speakers on the wall. Usually, the speakers are positioned out of the way on a 12-foot high shelf, pointed straight ahead, above the heads of customers, instead of angled toward seated customers. Simply positioning a sound system where it looks good or is out of the way doesn’t consider whether it provides adequate coverage or if people can even hear the music. A system needs to include the right kind of speakers for the room, focused directly toward seating areas.
Restaurants and bars tend to get loud, and when extra volume is needed there isn’t enough gain in consumer systems to be heard over people talking. Add the clatter of plates, bussing stations, and, if there’s a coffee station, steam noises, and audio may not cut through. Volume level, however, isn’t the only goal. Better sound coverage throughout customer areas is often more important, ensuring that ambient music can be heard throughout the listening area without excessively cranking up the speakers.
Restaurants and bars can have difficult challenges with room acoustics. Current design trends lean toward open spaces with flat lines of wood, glass or other materials. Many rooms are big reflective spaces and the only thing that absorbs sound is the people within them. The less crowded the location, the worse it usually sounds. It can still get loud with a lot of people in the room, but at least they absorb some of the sound. Taking acoustic design into consideration, there is always a trade-off between the physical acoustics of the space and the fidelity or intelligibility of a sound system. In some situations, the use of line-array technology, such as column speakers such as the JBL CBT Series can help focus sound at specific seating areas without bombarding the entire space with music.
Live Performance and Paging
Many coffee shops, bars and restaurants include live music in their schedules. A PA system with a professional mixing console, microphones and loudspeakers is vital to easy tuning, feedback suppression and quality sound. It’s important to consider that untrained or minimally experienced staff and performers will be using the system and that it needs to be as simple and efficient as possible.
Similarly, some restaurants depend on paging microphones to notify customers when their table is ready. Many employees aren’t knowledgeable about operating microphones. Using a wireless or handheld microphone near a speaker can result in squawky noises. Using automatic feedback suppression in commercial installations can prevent those issues.
The biggest concern in putting together a high-quality, long-lasting restaurant AV system is that owners need to allocate sufficient budget for the project. Hiring a professional integrator or AV consultant instead of self-selecting and installing equipment can minimalize sound issues and increase efficiency for the long-term. AV professionals can help mitigate speaker and microphone placement issues and, if need be, collaborate with an interior designer to make sure the equipment supports the overall look.
As trained professionals, they launch the process with a site survey or interview to gather all the information about what the goals are for the sound system. Because there are different levels of equipment, they can come up with a budget that serves the particular needs of a business.
As someone who has been in the audio business for over 20 years, I have seen numerous restaurants launch with a consumer rated sound system only to discover, before the first year passes, that they need to upgrade. Purchasing a professional system from the start can save money and effort and ensure a more pleasant listening experience for employees and customers alike.