How to Connect Multiple Speakers to an Amplifier without Damaging Anything
When setting up a commercial sound distribution system, understanding how to connect multiple speakers to an amplifier properly is crucial. This ensures the longevity of your equipment and the quality of the audio output. Commercial sound systems often employ Constant Voltage distribution to distribute audio signals efficiently.
Understanding Constant Voltage Amplifiers
Constant voltage amplifier systems (CVA) are commonly used in commercial sound installations. These amplifiers typically feature an output transformer supplying a 70-volt or 25-volt audio output. This design allows for long cable runs without significant signal loss.
How It Works: E/W Speaker Line Matching Transformers
In a CVA system, all speakers are connected via E/W speaker line matching transformers. These transformers help match the impedance between the amp and the speakers, ensuring optimal performance. A 100-watt amplifier can drive approximately 160 8-inch speakers, when each speaker is loaded to 1/2 watt (or 80 load).
Increasing the Number of Speakers
To accommodate more speakers, you can wire them either in parallel or series. However, the aggregate load must not exceed the amp's capability. For instance, if your amp can handle a 4-ohm load, connecting two 8-ohm speakers in parallel would be permissible. But if your amp cannot handle the lower impedance, wiring the speakers in series might be a better option, though it might negatively impact sound quality.
Wiring Techniques
Each of the two wires from a speaker should be connected to one of the two speaker posts on the amplifier. This process should be done carefully to avoid any damage to the equipment or compromise on sound quality.
Considerations for Amplifier Types
The approach to speaker connection varies based on the type of amplifier you are using.
Solid State Amplifiers
Solid-state amplifiers have a specified minimum impedance. Exceeding this can lead to damage. If you need to run more speakers, you have two options: series connection or series-parallel connection, especially if you have three or more speakers.
Tube Amplifiers
Tube amplifiers can tolerate a wider range of impedance. Their specified maximum impedance is more of a guideline, allowing a little higher or lower than the stated value.
Calculating Speaker Impedance
The impedance of speakers wired in parallel can be calculated using the formula: "sum of all the speakers divided by the product of all the speakers." For series wiring, simply add the impedances. Series-parallel systems require more complex calculations based on the wiring configuration. It's essential to keep the overall impedance within safe limits to avoid damaging the amplifier.
Conclusion
Properly connecting multiple speakers to an amplifier is a critical step in setting up a commercial sound distribution system. By understanding the principles of constant voltage amplifiers, speaker load, and appropriate speaker wiring techniques, you can ensure the best possible performance while safeguarding your equipment.