Technology and Enterprise Systems Forms and attributes: A system is a combination of parts that work together to achieve a specific result. Some systems are found in nature some are technological systems and some have people involved as part of the system. The parts of the system are connected together to enable an activity to be performed. The cause and effect relationship between systems How systems meet needs and wants and the consequent impact on society and the environment A specific technology process to assist in understanding how systems can be used and created. How to meet users’ needs whilst avoiding risks and inefficient use of resources. Our focus for learning is on:

Public Address Sound Reinforcement Systems

PA systems can be simple, or quite complex. All PA systems have some components that are common, even though they may look different.

At its most basic a PA consists of: Microphone Microphone lead Amplifier Microphone input – this may be a separate desk Speaker lead Speaker

Leads Leads are used to connect different components or parts of the system together. Microphone Leads Microphone leads are part of the input side of a PA System Microphone jacks are called XLR jacks. They have two different ends. These are called the male and female jacks. The male goes into the desk or input on the amplifier and the female plugs into the end of the microphone. Care Microphone leads must be wrapped carefully to ensure that the wires inside do not twist and eventually break.

Speaker Leads Speaker leads are part of the output side of a PA System Speaker jacks come in three different types. The ones on our school PA are called phono jacks. Both ends of our speaker cables are the same. The speaker jacks plug into the output on the amplifier and the input on the speaker. Care As with microphone leads, speaker leads must also be wrapped carefully to ensure that the wires inside do not twist and eventually break.

Adding components If you want to add a CD or tape player to your sound system you will need to use a different type of lead. This lead is called an RCA cable Generally they have a much smaller jack, and they are often coloured. These leads add components so they are part of the input side of your PA system. They need to come from the output on your player to an input plug on your amplifier or desk.