Live Sound Basics: Setting Up a PA System for Events and Gigs

Updated April 2026 · By the AudioCalcs Team

Live sound is unforgiving. There is no undo button, no second mix, and feedback screech in front of 200 people is a memory that does not fade. But the fundamentals are straightforward: get the signal chain right, size the system for the venue, set gain structure correctly, and manage feedback before it manages you. This guide covers the practical knowledge you need to run sound for small to medium events without embarrassing yourself or the performers.

Sizing a PA System for Your Venue

PA system power is measured in watts, but what matters is how loud the system can get at the listening distance. A general rule for spoken word events: 2-5 watts per person in the audience. For amplified music, 5-10 watts per person. A 200-person outdoor event with a live band needs 1,000-2,000 watts of total PA power.

Outdoor events need more power than indoor ones because there are no walls to reflect sound back toward the audience. Sound dissipates freely, losing 6 dB every time the distance from the speaker doubles. A system that fills a 200-person indoor room may only cover half that audience outdoors.

The Signal Chain: Source to Speaker

The live sound signal chain is: source (microphone or instrument) to mixer channel input, through gain and EQ, to the mix bus, to the amplifier, and out to the speakers. Each stage must be set correctly for clean, undistorted sound.

Powered speakers (also called active speakers) combine the amplifier and speaker in one unit, simplifying the chain. They are the standard for small to medium events. Passive speakers require separate amplifiers and speaker cables. For beginners, powered speakers eliminate the complexity of amplifier matching and reduce setup time by half.

Gain Staging: The Most Important Skill

Gain staging sets the level at each point in the chain so the signal is strong enough to be clean but never clips. Start at the mixer. With the channel fader at unity (0 dB), adjust the trim/gain knob until the loudest signal peaks at -6 to -3 dB on the channel meter. Then set the master fader to control overall volume.

The most common live sound mistake is running the channel gains too low and compensating with fader levels pushed above unity. This amplifies the noise floor and produces a hissy, thin sound. The second most common mistake is running everything hot until it clips, producing harsh distortion that the audience hears as aggression and fatigue.

Feedback Prevention

Feedback occurs when sound from a speaker enters a microphone, gets amplified, exits the speaker louder, re-enters the microphone, and loops until it becomes a howl. Prevention is far easier than correction. Keep speakers in front of microphones (never behind). Use cardioid microphones that reject sound from the rear.

During soundcheck, slowly raise each microphone channel until you hear the first hint of feedback (a ringing tone). Note the frequency and cut it by 3-6 dB with a narrow parametric EQ. This is called ringing out the monitors. On the main PA, keeping speakers well in front of the stage and angled away from microphones is the primary defense.

Microphone Selection for Common Sources

For vocals, the Shure SM58 is the industry standard dynamic microphone. It sounds good on most voices, rejects feedback well, and survives being dropped. For acoustic guitar, a condenser like the AKG C214 or Audio-Technica AT2035 captures detail, but a dynamic mic is safer for loud stages.

For drums, the Shure SM57 on snare and toms, a dedicated kick drum mic like the AKG D112 or Shure Beta 52A, and overhead condensers for cymbals is a standard setup. For amplified instruments running through DI boxes, use active DIs for passive pickups and passive DIs for active electronics.

• Vocals: Shure SM58 (dynamic, standard, durable)
• Snare/toms: Shure SM57 (dynamic, versatile, affordable)
• Kick drum: AKG D112 or Shure Beta 52A (dedicated low-frequency)
• Acoustic guitar: condenser preferred, dynamic in loud environments
• Keyboards/bass: DI box to mixer, no microphone needed