1. Buying the right PA for your band and building Glyn Chapman Acoustic Arrangements

2. Needs Analysis Who’s it for? What’s it for? Who’s going operate it? What worship styles? For now or for the future? Plan for occasional needs. What about video, lighting & electrics. What best serves the vision of the Church.

3. The Sound System Basic System Source Mixer Amplifier Loudspeaker

4. Inputs Microphones Dynamic (moving coil) Condenser Pick-Up Pattern Style DI Boxes (direct injection) Active/Passive Electro-Acoustics, Keyboard, Bass Radio Mics, CD, DVD, PC

5. Cables, Connectors, Multicore Balanced Cable

6. Cables, Connectors, Multicore XLR pin 1 gnd, pin 2 +ve (hot), pin 3 -ve (cold) JACK TRS: tip, ring sleeve (stereo jack) as balanced: tip +ve, ring -ve, sleeve gnd To unbalance: link gnd & -ve

7. Cables, Connectors, Multicore Multicore: How many sends? How many returns? How long?

8. Mixer Analogue ‘v’ Digital Number of inputs (channels) EQ Routing: Auxiliaries Powered or Unpowered

9. Processors Effects: Reverb, Chorus, Delay Compressor/Limiters Gates Graphic Equalisers Crossovers Speaker Controllers

10. Amplifiers Constant Voltage 100v Line Speaker load not exceed 75% of amp power. Low Impedance Example: 500w into 4ohm =300w into 8ohm =700w into 2ohm Allow for headroom up to twice speaker power

11. Speakers Power: RMS = Continuous Program = 2 x Continuous Peak = 4 x Continuous Sensitivity: SPL – Sound Pressure Level Ex:400w 96dB speaker is same level as 200w 99dB speaker I.e.you need twice the power for 3dB increase in level Add 2 nd speaker adds 3dB or 6dB if placed together

12. Speakers Inverse Square Law: - 6 dB per distance doubled Dispersion Low Impedance/100v Line Line Array Horn Loaded

13. Speakers

14. Top Tips Listen to advice from professionals Check your cables & connectors Throw away old, broken or unusable kit Use your ears Check your mid range EQ Don’t buy something just because it’s on offer Buy the right product for the job Cost is part of the specification

15. www.a-a.uk.com