Live Sound

How do you estimate the power required for a PA system?

The presentation gives a guideline of approximately 5 watts of total PA power per audience member.
Example: 100 people ≈ 500 W; 10,000 people ≈ 50,000 W.

What is the difference between active and passive crossovers?

→ Passive crossovers are typically built into speaker enclosures, receive amplifier-level signals, and are usually fixed-frequency.
→ Active crossovers require mains power, receive line-level signals from the mixing console, and send line-level signals to the amplifiers

What are dispersion angles and why are they important?

They describe how widely sound spreads from a speaker in the horizontal and vertical planes. They are important for achieving maximum coverage across a venue. The SPL is typically 6 dB lower at the outer edge of the specified dispersion angle than directly in front.

What are the key documents involved in advancing a live show?

he main documents are the channel list, stage plan and equipment rider/technical specifications.
A channel list specifies the channels required at the mixing console, while a stage plan is a top-down view showing the positions of the band and instruments.

What are the recommended audience noise limits given in the presentation?

HSE strongly recommends that the A-weighted equivalent continuous level should not exceed 107 dB, and the C-weighted peak SPL should not exceed 140 dB.

What should a channel list contain?

Channel number, instrument, microphone type, inserts, phantom power requirements, stand requirements, stage position and relevant notes.

What is the purpose of an RTA when tuning a PA?

Real Time Analysers (RTA) as part of the PA tuning process, alongside room EQ and phase relationships.