When most people think about their sound system, they think that it’s all about the speakers. While the quality of your speakers is important, the amplifier plays an equally vital role in sound quality and maximizing the performance of your speakers. Furthermore, using an incompatible amplifier can harm or damage speakers. It’s important to know that your amplifier is compatible with the speakers you’re using in order to protect your gear and get the most out of your system.
According to our friends at Selby, speaker retailers for 20 years, to determine if an amplifier is compatible with your speakers, it is essential to understand the basics of compatibility, which is determined by three key factors: power, impedance, and sensitivity. In this post, we’ll explain these parameters and how to use them to find an amplifier that is compatible with your speakers.
Power
Power refers to the amount of power an amplifier can deliver and the amount a speaker can handle or require without damage. It measures the wattage output of an amplifier and the wattage intake of a speaker. A common misconception is that more watts equal louder volume, which is not always the case.
When it comes to power, it is crucial to match the amplifier’s power output to the speaker’s power requirements or have an amplifier that is no more than four times more powerful. This prevents under-powering your speakers, which can cause audio distortion known as clipping. Overpowering your speakers can also cause damage, although it’s much harder to overpower than under-power. An amplifier with a low power rating will not produce audio at full volume without clipping, which leads to distorted audio that is likely to damage the speakers.
Amplifiers are often rated for Continuous Power (CP) and Dynamic (Peak) Power. Continuous Power, or CP, is the amount of power an amplifier can deliver consistently, it’s the most significant spec as it describes the amp’s normal operation. Dynamic Power is the highest wattage output of an amplifier during dynamic frequencies that are present during most audio signals like music. In simpler terms, an amplifier with a CP rating of 100 watts will typically deliver 100 watts of power, but it may deliver 150 or 200 watts for a short time, that’s Dynamic Power. The range between Continuous and Dynamic power ratings is called ‘headroom’. Generally speaking, the more headroom an amplifier has, the lower the risk of clipping.
Power specifications on speakers can be more complicated, as different brands have their own methods of indicating power capabilities. Some brands use Maximum Continuous Power, Minimum Recommended Power, or Maximum Short-term Peak Power ratings, while others list recommended amplification power range. To ensure that your amplifier delivers enough continuous power to the speakers and prevent clipping, it is important to compare the speaker and amplifier power specs.
Impedance
Impedance is a measurement of electrical resistance, usually measured in ohms (Ω). Don’t worry, it’s not necessary to understand electrical resistance to compare impedance specifications. The most important rule is to make sure the amplifier impedance is lower than the speaker impedance to avoid damaging the amplifier.
Although impedance is important, it’s usually not often a significant issue, as most consumer speakers have an impedance of six to eight ohms. It’s worth noting that amplifiers will deliver more power into a lower ohm rating. For example, an amplifier that can deliver 180 watts of power into an 8 ohm load can deliver 265 watts into a 4 ohm load. If the impedance rating of your amplifier is much lower than that of your speakers, it will deliver less power. It’s usually best to match the impedance ratings as closely as possible.
Sensitivity
Sensitivity is a specification that only applies to speakers. It measures the volume in decibels a speaker produces from 1 meter away when supplied with 1 watt of power. Sensitivity does not indicate speaker quality, it only determines the amount of power the speaker needs to reach a certain volume. Notably, to increase the volume by 3 dB, you need to double the amplification power. The required power increases exponentially with volume level, and volume decreases significantly as the distance from the speaker increases. This is why amplifiers have high wattage outputs.
When considering speakers, examine their sensitivity rating to determine how well an amplifier will drive them. If you want to play music at a specific volume, you can calculate the minimum power rating your amplifier will need. As a general rule, if you want to play at higher volumes, it’s safe to get an amplifier with more power than your speakers require.
That’s all there is to it! By understanding these three specs, you can determine the compatibility of any speakers and amplifiers. If you’re looking for a new piece of equipment for your audio setup, these specifications are crucial to know so you can protect your speakers and get the most out of your gear.
