Portable Sound Meets the Immovable Space

The global pandemic spurred the need for alternative meeting spaces for business. It's a trend that's only accelerated in the last year as businesses dealt with repeated openings and closings, but it has now become increasingly useful for employees to gather for group events, such as presentations and training, as businesses look for flexible ways to restore collaborative work environments.

However, alternative meeting locations such as rooftops and lobbies — chosen for health-safety reasons to help participants space themselves apart or keep air freely circulating — often need to be fitted with temporary audio and video solutions. Portable sound systems can fill those spaces with sound, enabling presenters to be heard with ease and clarity.

Fortunately, there are good-sounding, affordable, and easy-to-use sound systems available. They're also easily configurable to fit the specific needs of meeting spaces without requiring an engineering degree to operate, and battery powered, enabling them to be used in more alternative meeting venues.

Pieces of the Puzzle

While designed for grab-and-go applications, these portable solutions have the same primary components as an installed sound system: loudspeakers, amplifiers, and mixers. They are also often integrated into single, user-friendly units. For instance, the Bose Professional L1 Pro Portable Line Array System — a regular contender on best-of-sound system lists — has a subwoofer, which acts as the single loudspeaker column's support base and has an audio mixer integrated into the assembly. The mixer has XLR inputs for professional microphones (most meeting applications won't require more than two microphone inputs, for presenter and guest) as well as an RCA stereo input and a 1/8-inch stereo input — formats that can accommodate most external audio sources. A 3.5-mm-to-RCA cable can easily connect a laptop or tablet to the sound system, while a Lightning-to-RCA adapter does the same for a compatible mobile device.

Most portable sound systems are designed with ease of set-up in mind, requiring little else of the user beyond the on/off switch and volume control, while built-in DSP avoids audio artifacts like distortion and clipping. However, they cannot elide the realities of physics. Feedback — the high-pitched squeal that occurs when the microphone and loudspeaker interact acoustically — is the main nemesis for nonprofessional audio-system users. Some manufacturers have provided for that, including Bose Professional, with technology that specifically allows considerable latitude for microphone and loudspeaker placement before feedback occurs. This allows presenters to stand directly in front of the column loudspeakers without inducing feedback, thus also eliminating the need for a monitor loudspeaker.

Following the 3 P's

Choosing a portable sound system boils down to the three P's:

Power: How big are the spaces you're using? Choose based on the largest one you'll typically work in. Turning down the volume for smaller spaces is easier than trying to push an amplifier to its limits in a larger space. Power is measured in watts, while volume is measured in decibels (dB). A 60-watt PA can deliver over 100 dB. This allows speech to fill a space for 30 or 40 people without having to turn the volume up high and risk distortion. (For comparison, televisions play around 70 dB.)

Purpose: Will you only be focusing on the speech, or will there be music, as well? Adding music to a presentation will require more power (i.e., higher wattage) and preferably a subwoofer for fuller frequency range. It also allows the PA to better be used for background music between presentations.

Price: The proliferation of PA systems of all types means there are several price points to choose from, although price, quality, and features are usually related. Depending on the size and type of system (power, number of loudspeakers, features such as number of inputs, and effects processing such as reverb), prices will range between about $500 for entry-level systems and $4,000 for tops-of-the-line.

Portable Sound System Best Practices

As we've seen, modern portable sound systems automate a lot of their functionality — but there are practices that can further enhance the benefits.

Loudspeaker positioning: A key metric is dispersion: the area within which a PA's sound is distributed, expressed as degrees, and measured horizontally and vertically. Sound system loudspeakers can have various dispersion patterns of between 40 and 90 degrees horizontally. However, a narrower dispersion range of between 40 and 60 degrees is often preferable for speech purposes to keep sound focused on the audience, and to avoid reflections from side walls. This keeps speech, which takes place largely between 500 Hz and 2 kHz, as intelligible as possible, without having to increase volume to reach listeners.

Venue size and type: Hard surfaces such as walls, floors, and glass windows can create sonic reflections. These can help propagate sound but can also interfere with speech intelligibility. It's equally important to aim loudspeakers away from those surfaces as it is to aim them toward listeners. Non-reflective or even absorptive surfaces — carpeted floors or acoustical ceiling tiles, for instance — will help mitigate those issues.

With portable sound systems, meetings of all types can successfully take place in alternative spaces as the array of meeting spaces expands.

A hand using a mobile device connected to a Bose Professional L1 Pro Line Array system

Portable PA sound systems can fill an alternate meeting space outside of the office with superior sound.