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How to Install a 100V Line Audio System | Audio Volt

How to Install a 100V Line Audio System | Audio Volt

This guide will assist you in installing your 100V Line amplifier, speakers, microphone and accessories. 100V Line is a different type of audio system compared to domestic hi-fi, or low-impedance systems, and some of the wiring and installation procedures are different. You may not require or have all the components shown so you can skip the parts that do not apply.

***It’s important to note that not all installations are the same. The guide will cover most aspects and all of the key installation practices, but if you’re still unsure please get in touch with your order details so we can assist you further.***


  • Amplifier Installation
  • Speaker Installation
  • Balancing Amplifier Load
  • Terminals and Connections
  • Speaker Cable
  • Media Players, Volume Controls and Accessories
  • 100V Line Amplifier Installation & Wiring

    100V Line Amplifiers can seem complicated but in reality they are very simple, and in some cases easier to install than domestic hi-fi amplifiers.

    Common Amplifier Wiring Processes

    100V Line Amplifiers usually have several output terminals to connect speakers, but you only need to connect your speaker cable to two of them - COM and 100V.

    COM is the negative terminal, whereas 100V is the positive terminal - you only need 2-core speaker cable for 100V Line installations (see more on wiring below). Speaker cable is usually colour-indicated with black as the negative (COM), and red as the positive (100V).

    When routing cables for the speakers, you can either run them in a daisy-chain configuration, or run them separately with a speaker cable from each speaker coming back to the amplifier (or a combination of both). In either case, you just need to insert the speaker cable or cables into the corresponding terminals.

    In cases where you have a lot of cables that won’t fit into a single terminal, you can route them through a block terminal first, and connect the output of this into the amplifier.

    Multi-zone Amplifier Wiring

    Multi-zone amplifiers wire in the same way as mentioned above, however, they will have multiple output terminals with each one relating to a separate zone.

    Some amplifiers will have multiple COM and 100V terminals, whereas some will have a single COM terminal, however, the wiring remains the same - connect your black (negative) strand of speaker cable to the COM terminal, and the red (positive) strand to the 100V terminal. Do this with a separate run of cable for each zone.

    100V Line Speaker Installation & Wiring

    Wiring 100V Line speakers is very simple as you don’t need to worry about balancing impedance, you just have to consider the overall wattage, and they can be connected in various ways with no signal or quality loss.

    Speaker Wiring Processes

    Speakers can be connected to the amp in one of two ways. They can all be connected individually with their own run of cable, or they can be linked together in a daisy-chain configuration, where each speaker links on to the next.

    As long as the speaker cables are connected to the corresponding COM and 100V terminals on the amplifier, you can use both methods, or a combination of both on the same amplifier.

    100V Line Speaker Tappings

    100V Line speakers will have various tappings, or wattages that relate to the output power. An example could be 2.5W, 5W, 10W, 20W & 30W. An increase in wattage equals an increase in output power.

    You can only select one wattage at a time, and this is selected by either a rotary dial on the speaker, or the terminals on the speaker you wire into. The wattage you select is dependent on the amplifier power and is very important to get right.

    Some speakers also have an OFF setting (where do audio will play), and an 8 Ohms setting. In the case of 100V Line, it is very important to NOT SET THE SPEAKER TO 8 OHMS. This setting bypasses the transformer on the speaker and allows the full 100V to travel down the cable to be passed into the speaker, which can blow speaker and even damage the amplifier.

    Balancing Amplifier Load & Speaker Power

    When configuring a system and installing the speakers, it is very important to ensure the combined total wattage of the speakers does not exceed the rated power of the amplifier.

    For example, 12 x speakers set to 10W each will result in a 120W load, so you will need an amplifier that is 120W minimum, although it’s always best to leave 10% headroom where possible to account for fluctuations in signal.

    If the total combined wattage of the speakers is more than the amplifier then it will overload the amplifier and cause it to break or even burn out.

    Multi-zone amplifiers differ in how they handle output wattage per zone. For example, the Monacor PA-12040 has 4 x 120W outputs, where each zone is independent and cannot exceed 120W. In contrast, the Inter-M PA-224 is 240W 5-zone, but the 240W is shared across all zones.

    Terminals & Connections

    There are different types of connections and terminals that can be found on 100V Amplifiers and speakers. While the method of connecting the cable may differ, the wiring practices outlined above remain the same.

     The three main terminal connections are:

    • Screw Terminals
    • Spring Terminals

    • Euroblock/Phoenix Connectors

    Screw Terminals

    Screw terminals are found on the majority of amplifiers. You simply unscrew the terminal to reveal a gap for connecting the speaker cable, and screw it back in to secure the cable.

    You can also find screw terminals with a banana plug socket on a lot fo wall-mounted speakers, where the installation process is the same.

    Spring Terminals

     Spring terminals are commonly found on speakers, in particular in-ceiling speakers. The connectors are spring-loaded, meaning you just have to hold them down while inserting the cable. Once released the clamping force will hold the cable in place. This makes for a quick and easy installation.

    Euroblock/Phoenix Connectors

    Euroblock, A.K.A Phoenix Connectors are similar to screw terminals but instead of connecting directly to the amplifier or speaker, you connect the cable to the connector which is removable to ease the installation. Simply remove the connector, unscrew the terminal and insert the cable. Screw it back down to secure it in place and reinsert the connector.

    100V Line Speaker Cable

    When installing a 100V Line system it’s best to use double-insulated cable and avoid thin car audio or hi-fi cables. This is down to a few factors.

    Firstly, as 100V Line is sending a 100V signal down the speaker cable, it will generate a bit more heat than a typical stereo hi-fi amplifier. While it’s not a massive amount, it will increase with the amount of power the system is using so it’s always best to have this in place. We recommend a minimum gauge of 0.75mm.

     Another reason is it retains signal quality over long distances. 100V Line audio systems can be run for hundreds of meters, so good quality double-insulated cable will retain signal quality over this distance while reducing interference and wear.

    We offer double-insulated 1.15mm speaker cable which can be used for any installation, and can even be used outdoors. You can view this here -

    Microphones, Media Players, Volume Controls & Accessories

    100V Line Systems allow you to connect a number of devices to enhance the system or provide additional features.

    Paging Microphones

    Probably the most common device people add to a 100V Line system is a paging microphone. This sits on a desk and with the push of a button allows you to make announcements over the system - it’s perfect in warehouses and office environments.

     All 100V Line mixer amplifiers will have an XLR or 6.35mm Jack input for a paging microphone, and some amplifiers will even have bespoke microphones that can be connected over CAT5/6.


    Media Players

    Media players provide a number of inputs which is ideal when using a power amplifier, as they only tend to have a single input.

    Media players will connect usually via RCA or an XLR connection, and provide a number of inputs such as microphone inputs, AUX inputs, Bluetooth, FM, SD, USB and more. The inputs will depend on the model of the media player.

    It’s worth noting that mixer amplifiers have a lot of the features a media player provides, so it’s not always necessary to have one.


    Volume Controllers/Attenuators

    Volume Controllers provide local volume control to a specific area, and are primarily wall mounted. They install and look like a dimmable light switch.

    Every model of volume controller will have different terminals, so please reference the manual when installing.


    FM/DAB Aerials

    Several mixers amplifiers, such as the RM series by Adastra will have a built-in FM/DAB tuner. In order to receive the stations however you will need to connect an aerial. Any compatible aerial will work, however the amplifiers may have an ‘F-Type’ connector rather than COAX (this is the case with Adastra products).

    In this situation you will need an F-COAX adapter in order to connect the aerial.


    If you require any further assistance regarding purchasing a Lithe Audio product please contact us on 02476 369890 and one of our experts will be happy to help. Or use our Request a Call Back page for a FREE no obligation system design & consultation service.

    Previous article In-Ceiling vs On-Wall vs Horn Speakers - Which one should you choose?
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