Mobile PA systems for outdoor applications: no electricity, no fixed installation but still a good sound quality?

These tips will help you to make even better use of your outdoor PA system

Anyone who wants to implement an outdoor event will require a mobile PA system. The advantage of these systems is that they have been designed for easy installation and perfect usability. You can achieve an even better sound if you follow our tips for operating mobile sound systems.

The most important factor when selecting a mobile PA system for outdoor use

Mobile PA systems are independent systems. You have got a device that contains all the important features: amplifier, speaker and rechargeable battery. With these PA systems, it is unnecessary to choose the right amplifier.

The sound pressure is the key feature when selecting a mobile PA system.

And there is a general rule: the higher the sound pressure is of the mobile system, the larger the area you can cover with the system. In the low-frequency range, larger membranes help to move larger air masses. This allows you to achieve a rich and powerful sound.

Mobile PA systems are powerful all-rounders: in addition to a bass-midrange speaker, they feature an integrated tweeter, so they are able to reproduce a wide frequency range from bass to treble. But this general rule alone is only of limited help in the selection process.

"How much power does my mobile PA system need for outdoor use for X people in Y square metres?"

There is no general answer to the question of how large the mobile PA system has to be for a certain area or number of people. Scenarios for outdoor PA systems do vary. You require a different PA system for 100 pupils in a schoolyard than you do for 100 listeners at a presentation in front of the town hall and ultimately even every schoolyard sounds different. As an exception, the following applies for mobile PA systems: the more power, the better. That is why the all-rounder for mobile PA applications is efficient with a powerful sound.

It is better to use a mobile PA system with some power reserves. Hence, you can achieve maximum flexibility and meet versatile requirements without pushing the system to its limits.

If you want to play or amplify music, use a larger system to be connected

Extendible mobile PA systems of a modular design can do both: speech and music events. The presenter can deliver his speech first and then provide the audience with music. Thanks to their 2-way design, these systems are able to transmit all relevant frequencies. The speakers feature the appropriate diameter to reproduce different frequencies at high volume levels. However, high volume levels are often not the relevant strength of these speakers. It is their interaction at larger events:

Larger mobile PA systems should definitely be linked together as required. Thus, multiple PA systems can be combined into one system.

Communication between multiple mobile PA systems often takes place via radio signal. One of the PA systems is the main system or master system. Each system has got controls for volume and sound. Thus, the PA system can individually be adapted to local conditions. In order to cover large areas, mobile PA systems can often be extended with additional systems using a wireless link.


The effect of (missing) reflection points

Why don't you do a test: Use a Bluetooth system with the same volume level in your living room and on a large open field. On the field, the speaker will quickly lose power if you move just a few metres away. The sound is lost in the open space. That is why scepticism is always advisable when general estimates are stated on the transmission range of a mobile PA system.

The most important question: just speech, or music and speech?

  1. Solely roadshow and events which exclusively require speech transmission.

    a. Mobile - sound source and audience are on the move: city tours and museum tours, processions, markets, dangerous situations with security personnel, announcements in a team, any kind of parade. Those are real situations for mobile PA systems which are constantly on the move.

    b. Stationary - sound source and audience are stationary: rallies, trade fairs, sales events, presentations, information stands.

  2. Stationary events with speech and music: school parties and company parties, trade fairs, city festivals or sporting events.

If you only want to transmit speech to small mobile groups, a portable system is sufficient. Do not expect any sound miracles from such PA systems. These systems are voice-optimised and limited due to a smaller diameter of the speaker. You can wear such a PA system on your belt or as a speaker on your back. Megaphones are also used for such events, especially for rallies and sporting events.

Large events with speech and music transmission

If large PA systems are not suitable for the event, you can also use a small mobile solution for such events. In this case, several mobile active systems are used, depending on the size of the area to be covered. Radio networking is used for this solution to avoid a trip hazard. The maximum radio range of mobile PA systems is limited and should not be used to its full extent. Thus, you have still got a reserve available. This guarantees a high operating reliability. In particularly extensive PA scenarios, such as street festivals or sports fields, the master system must therefore be positioned centrally between the additional speaker systems. For large outdoor applications, it can be useful to study a plan of the event site and position the mobile PA systems accordingly.

For large events, please ensure the maximum radio range and interference-free radio frequencies when using a PA system in outdoor applications

Especially at street festivals or outdoor festivals, you should also find out whether other radio frequencies are used and which ones they are. To ensure interference-free operation, you may have to switch to alternative frequencies.


The maximum radio range specified in data sheets always refers to direct visual contact (free field), without obstacles in between. Everything between the transmitter and receiver affects the operating range

Remember: if you connect two or more speaker systems via radio link and also use two wireless microphones, you are already occupying three different radio frequencies which must not interfere with each other.

Please pay attention to positioning and alignment at your events when using a PA system for outdoor applications

In addition to volume, there is another reason to use several speaker systems for a larger event: acoustics. It is not ideal to frontally fill a crowd of 100 or more people with just one speaker system, even if it would theoretically be loud enough. It is better to use additional speakers for the PA applications in order to evenly radiate the sound from several systems. Thus, permanently installed systems always feature several speakers.

When possible, the PA systems should not be placed in the primary crowd, but a few meters around it. Please make sure to avoid the risk of accidents when positioning the mobile PA systems. Do not place the systems in a frequently used passageway and, of course, never in an escape route.

The speaker systems should radiate the sound towards the audience. Ideally, the speakers should hang or stand at the height of the listeners' ears or slightly above it.

If you are planning a PA application for a standing crowd you should use stands to bring the speaker systems to ear level. If the audience is seated and you are standing on a raised stage, the speaker system can also be placed on the floor of the stage or on a small box. Tip: the speaker with the microphone should stand behind the speaker system, if possible. This reduces the susceptibility of unwanted feedback.

Would you also like to support your customers during the planning stage of a PA system? We have prepared a few tips from our project team at MONACOR to help you during the planning stage of a PA system.

source image header: querbeet / iStock / Getty Images

MONACOR INTERNATIONAL offers a high quality and perfectly adapts products to their target groups. Look on our respective brand website to find out what our product brands got in store for you.