Designing a sound system from scratch involves several considerations. Selecting the right amplifier to pair with your loudspeakers can initially seem challenging, but it becomes straightforward once you grasp a few fundamental audio and electrical concepts. Ultimately, it's about matching amplifier power to loudspeaker performance. Here are key terms and concepts you'll need to understand to make informed decisions.
Essential Speaker and Power Concepts
- Amperes
- Amperes, commonly shortened to amps (but don't confuse this with an amplifier), measure electrical current.
- Voltage
- Voltage indicates electrical potential. Increasing the volume on an amplifier raises the voltage it delivers.
- Watts
- Watts measure power, calculated as volts multiplied by amperes. Loudspeaker manufacturers specify loudspeaker power capability in watts.
Watt = Volts x Amperes
- Ohms
- Ohms measure resistance. Related to Ohm's Law, explaining the relationship between voltage, current, and resistance.
- Impedance
- Impedance I measured in Ohms, impedance describes the resistance the loudspeaker presents to the amplifier. It fluctuates with sound frequency, meaning a 6-Ohm loudspeaker rarely remains precisely at 6 Ohms. Engineers typically assign a nominal impedance rating—such as 6 Ohms—to represent an average impedance for amplifier matching and loudspeaker selection.
- Sensitivity
- Sensitivity indicates how efficiently a loudspeaker converts power into sound. Higher sensitivity means the loudspeaker requires less amplifier power. For a deeper dive, see our blog on wattage and sensitivity.
Determining Amplifier Power Requirements
Loudspeaker specification sheets (often called spec sheets) list power ratings—also known as power handling or capacity—in watts. This rating is crucial for designing a sound system tailored to its intended application, from medical ultrasound equipment to stadium sound systems.
A practical guideline is choosing an amplifier capable of delivering roughly twice the power your loudspeakers require during regular use. This extra capacity, known as "headroom," ensures the amplifier can comfortably handle brief peaks in performance. Ideally, your amplifier should operate between 60% and 70% of its maximum capacity during typical usage.
Another key factor is how your loudspeakers will be wired: parallel (common) or series (rare). In parallel wiring, loudspeakers are connected positive-to-positive and negative-to-negative, decreasing total impedance and allowing the system to draw more power from the amplifier.
Amplifiers provide more current to lower-impedance loudspeakers (e.g., 4 Ohms) compared to higher-impedance loudspeakers (8 or 16 Ohms). Calculating the total impedance for loudspeakers wired in parallel is straightforward when all loudspeakers have the same impedance: divide the impedance of a single loudspeaker by the total number of loudspeakers. For example, four 8-Ohm loudspeakers wired in parallel result in a total impedance of 2 Ohms (8 ÷ 4).
Choosing the Appropriate Amplifier Type
Amplifiers come in three primary configurations:
- Mono amplifiers (single output) are ideal for applications such as PA systems.
- Stereo amplifiers (two outputs) suit high-fidelity audio setups or headphones, where separate left and right channels are needed.
- Multichannel amplifiers (more than two outputs) support surround-sound systems or setups involving multiple types of loudspeakers in different locations.
Manufacturing loudspeakers combines precise science with subjective art, meaning performance ratings are often approximations. Selecting amplifiers and loudspeakers from the same manufacturer ensures components are engineered to the same testing standards, enhancing compatibility and reliability.
Early amplifiers continuously delivered power to loudspeakers, which was highly inefficient. Today, Class D amplifiers combined with digital signal processing (DSP) technology offer significant advantages. Class D amplifiers function by rapidly switching their internal components on and off, vastly improving efficiency, generating less heat, reducing weight, and increasing longevity.
DSP technology further optimizes audio performance by electronically adjusting signals to ensure sound clarity and accuracy. DSP can address shortcomings in listening environments, timing discrepancies, and loudspeaker performance limitations.
Partner with MISCO for Customized Loudspeaker and Amplifier Solutions
Selecting the right amplifier and loudspeaker components requires expertise in audio engineering and an understanding of your specific application. MISCO brings over 75 years of experience in designing and manufacturing high-quality audio solutions for professional audio, commercial applications, defense, aerospace, and more.
Whether you require custom-engineered loudspeakers, precision amplifiers, or comprehensive audio system solutions, our experts are ready to assist you. Through rigorous testing, advanced technologies, and precision manufacturing, MISCO ensures your loudspeakers and amplifiers deliver unmatched reliability and performance.
Ready to enhance your sound system with proven expertise and tailored solutions? Contact MISCO today—we’re here to bring your vision to life with precision, reliability, and outstanding audio performance.
