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Monday, July 02, 2012

Amplifiers: PA System Amplifier Equipment

All public address systems (PA systems) have three basic components.
1. Microphones
2. Speakers and
3. Amplifiers
Download entire Wireless Sound System Setup Guide Here.

Input and Output Connections, (Jacks)
First are there enough microphone inputs for your purposes? Generally speaking 2-4 microphones are all most presentations will need. Too many microphones will restrict your ability to amplify. Every time you double the number of active microphones, you lower the maximum level of amplification.

Are the inputs compatible with the microphones? All of our microphones are compatible with our amplifier inputs so you don’t need to worry about compatibility. Does the amplifier provide phantom power if your microphones require it?

S602 Megaphone
Horn - SW610 Half-Mile Hailer
S1294-70 Speaker

Are there line level inputs? Line level inputs accept higher input levels from equipment such as tape recorders, CD players or other audio gear. This may be important if you want to play back recordings through the PA system. Some presenters will use this to entertain people before the event.

Are there line level outputs? Your tape recorder will give you better recordings if you can record directly from your sound system. You can damage equipment if you try to record from the speaker outputs because the voltage will be quite a big higher than the recorder input is designed for. Our Amplifiers have a line out to record your presentation while it is happening.

The output of the amplifier is described by the wattage output and the distortion. These are also the more important rating of the system. The wattage is going to determine ultimately how loud you can get your system. This is also the rating that gets kicked around a lot in the specifications. Below are a few specifications and how they should be interpreted.

This is the power output. This specification should tell you the power level in Watts (RMS).  RMS means “Root Mean Square.” Basically, it gives a more realistic rating of the amplifier’s continuous output. Peak power will tell the maximum output the system can generate for a short time, but this figure won’t tell you how well it will perform for long periods of time.  RMS power may be also noted on the specifications as continuous power. A properly listed power rating will tell you the output in watts RMS into a resistance measured in ohms. Most PA speakers are 8ohm.

This specification is an indication of the amount of distortion you can expect. The lower this number, the better the sound should be. For nearly all good amplifiers for PA purposes, this number should be lower than 1%. For example, a 50Watt RMS amplifier into 8Ohms has a distortion level less than 1%.

Avoid Overkill. Buying a system larger than you need is costly. The more efficient your system the better off you will be.

If you are buying a system that will be permanent, purchasing a system made up of separate components and installing them may be of benefit. Be sure to install good security features to keep the equipment safe when it is not in use.

There are many good portable PA systems available on the market which will give you good coverage and plenty of power. These systems are built with the microphone, amplifier and speaker already matched up. The advantage is reduced set up time, just plug and play. In addition these systems can be stored in a locked area when not in use.

There are a few important factors to consider when purchasing a portable system. If it is a portable battery powered PA, check the batteries will last all day at full volume. Battery capacity is measured in amp-hours (AH). Batteries that are rated for 8AH are going to last longer than batteries rated 3.2AH.

Be careful of systems that don’t tell you the actual output of the amplifier. Some products may be advertised telling you the capacity in the speaker or speakers included with the unit as a system. This will tell you about the speaker, not about the amplifier. It would be like advertising a car that has tires capable of driving 300mph, but they don’t tell you that the car can only travel 25 mph.

Talk to others in your industry about their portable PA system. Call the company you are researching for references. Make sure that you get a warranty in writing.

AmpliVox Sound Systems offers a 6 year warranty on our Portable PA systems.