Audio for Auditoriums and Events: Mixers, Speakers and DSP

Plan auditorium and event audio as a chain: microphones, a mixer, a processor, amplifiers and loudspeakers sized for the audience and the room. Decide first whether the room carries speech, music or both, then size the loudspeaker coverage, the mixer inputs and the processing to match. Good coverage matters more than raw power.

What does an auditorium audio system include?

Five blocks make up the system. Sources, such as microphones and playback, feed a mixer. A processor adds filtering, delay and feedback control. Amplifiers drive the loudspeakers, and the loudspeakers spread sound over the seating. Monitoring and recording feeds complete the picture. Each block can be a separate unit or part of a combined product, and the design shows how they connect.

How many mixer channels does the room need?

Count the sources you will use at one time, then add spares. A lecture hall with a few wireless microphones and a laptop needs little. An event space with a band, hosts and playback needs many inputs and several mixes. The Allen & Heath SQ-6 has 48 input channels, 24 local mic inputs (XLR) and 36 busses. The Allen & Heath Avantis with dPack reaches up to 96 input channels and 56 busses. Yamaha's TF5 offers 33 motor faders and 32 analog mic/line inputs, and the TF3 25 faders and 24 inputs. Choose the fader count by how the operator works, and the input count by the sources.

What does the processor do?

A processor handles routing, equalisation, delay and feedback control, and it can be the difference between a clear hall and a harsh one. The Allen & Heath AHM-64 has a 64x64 processing matrix and an optional Dante 96kHz 64x64 card for network audio. The Crestron DSP-860 offers eight mic/line inputs with a 66 dB gain range and 3.0 ms latency, which suits smaller spaces. Keep latency in mind for live sound, where a delay between the voice and the speakers is distracting.

How do you choose amplifiers?

Amplifiers must match the loudspeakers and leave headroom. The Bose PowerSpace P21000A gives 1000 watts per channel, and the Bose PowerSpace P4300+ is a 1RU four-channel amplifier with integrated DSP. Plan the number of channels from the number of loudspeaker zones, such as the stage area, the main seating and the balcony, and check the rack space and cooling.

Which loudspeakers suit which space?

Loudspeakers are chosen by coverage, not only by size. Low ceilings suit loudspeakers with a wide, controlled pattern, such as the Bose EM90-LP EdgeMax with 80 degree vertical coverage. Surface-mounted speakers like the Bose DesignMax DM8SE, a two-way 8 inch unit with a 52Hz to 20kHz range, suit commercial interiors. Music and events need bass, and a subwoofer such as the Yamaha DXS12mkII adds a 12 inch powered driver with a 1020W class-D amplifier. For open-air events, products such as the Bose ArenaMatch AM10 are rated for stadiums, arenas and outdoor entertainment venues.

How do the room's acoustics affect the design?

Acoustics set the limit of what equipment can achieve. Hard walls, glass and bare floors make a hall echo, so speech loses clarity however good the loudspeakers are. Aim loudspeakers at the audience and away from walls where possible, and treat the worst reflecting surfaces with absorbing panels. In long or deep halls, add delayed loudspeakers part-way back so that people at the rear hear the sound at the right time. Have the room surveyed before the loudspeakers are chosen.

Which microphones do presenters need?

Presenters and hosts normally use wireless handheld, headset or lavalier microphones. The Shure GLXD14+/93-Z3 is a GLX-D+ presenter system. Confirm that the wireless system is intended for use in India, and test for interference in the venue. Our guide to conference room microphones covers the types in more detail.

What should be tested before the event?

Test the system with people in the room, because an empty hall sounds different. Walk the seating while someone speaks, check for dead spots and feedback, and set the mixing position where the operator hears what the audience hears. Corporate AV designs audio for auditoriums, halls and events across India. See our auditorium audio solutions, event AV and installed audio solutions. Browse audio DSPs, amplifiers and mixers, speakers and audio systems, and the Allen & Heath and Yamaha ranges. Request a quote with the hall size and seating.

Auditorium audio needs a design, a careful installation and proper testing: see our AV design services, AV installation services and AV testing and commissioning services.

Frequently asked questions

What equipment does an auditorium audio system need?

Microphones, a mixer, a processor, amplifiers and loudspeakers, plus monitoring and recording feeds. The design sets how they connect and how many of each the room needs.

How many mixer channels do I need?

Count the sources used at the same time and add spares. A lecture hall needs few inputs, while an event with a band, hosts and playback needs many. Mixers such as the Allen & Heath SQ-6 offer 48 input channels.

Why do I need a processor as well as a mixer?

A processor handles routing, equalisation, delay and feedback control for the whole system. It lets you tune the room, which a mixer alone does not do well.

How do I choose loudspeakers for a hall?

Choose by coverage pattern and the ceiling height, then check the power and frequency range. Even coverage across the seating matters more than raw power.

Should the audio be tested with an audience?

Yes, or at least with people sitting in the seats. An empty room sounds different from a full one, so retest the levels and check for feedback once people are in the room.