How to Choose an Amplifier for Speakers?

Speakers are one of the most important components of any audio system. But since there are many different types of speakers, there are also many types of amplifiers. This article will walk you through the basics about what an amplifier does, what kind of power is needed for each speaker type, and how to choose the right amplifier for your needs.

The first thing about choosing an amplifier is determining which type you need to amplify your sound effectively.

Before you get started, make sure you get an amplifier that has enough wattage to match the volume rating on your speakers. Usually, the rating is printed on the amp. Use this rating, along with your speaker’s efficiency rating, to choose an amplifier that will supply enough power for your speakers.

The rating on the amp is listed in watts, while the rating on your equipment is usually in dB(SPL). A dB(SPL) rating indicates how loud a speaker can play before distortion begins to appear. A good wattage rating for most speakers is at least 50 watts.

Table of Contents

Understanding Speaker & Amplifier Matching

Key to ensuring effective synergy between your speakers and your amplifier is having a basic grasp of HiFi vocabulary. We’re talking about the essential terms used in speaker and amplifier specifications which will prove critical to your search for awesome, long-term HiFi sound.

The three terms we’ll be tackling in this article are impedance, power, and sensitivity. We’ll kick things off with ‘impedance’

1. Impedance

You’ll find impedance on the spec sheets for both specs and amplifiers, but what is it? Put simply, it can be thought of as a measure of the electrical resistance of your components, measured in ohms. Resistance will often be represented by the Ω symbol, like 10Ω. For those with experience in electronics, you’ll understand precisely what resistance is, but for our (somewhat simplified) purposes it’s not vital to have in-depth knowledge.

The bottom line:

Our general advice would be that it’s fine to connect speakers with a higher impedance to an amplifier capable of operating with a lower impedance, but what you shouldn’t do is connect speakers with a lower impedance (say, 4 ohms) to an amplifier with a higher minimum impendence (10 ohms, for example).

Almost all of the time, that’ll ensure a safe speaker and amplifier pairing, and it takes out most of the complicated maths.

As an aside, you’ll find that many modern speakers and amplifiers have also moved towards ‘compatible with’ ohm ratings, which greatly simplifies things for everyone.

2. Power

So, let’s turn our attention to power, but beware – things are about to get a little confusing.

Just like any electrical item, power in HiFi and home cinema equipment is measured in watts. Often, this leads people to make the mistake of believing that more wattage means greater volume output, but that’s not always the case.

Wattage in speakers and amplifiers is about how much power a speaker can handle and how much power an amplifier is putting out. In the past, people would often combine a low-watt amplifier with high-watt speakers and call it a day. However, that’s not the path to the best match. To get there, we’re going to have to wade through some HiFi jargon weeds.

Amplifier spec sheets will often reference Continuous Power (occasionally referenced as Continuous Power Output or Continuous RMS power) and Dynamic (or Peak) Power. For our purposes, we’re going to pay closer attention to Continuous Power, because it indicates how powerful an amplifier is in normal operation.

The bottom line:

Pay attention to Continuous Power and the wattage your amplifier is putting out, and stack that up against the recommended amplification levels on your speaker. By comparing these two figures, you’ll be able to gauge the suitability of your pairing.

3. Sensitivity

This one’s just for speakers, and rather than wattage, sensitivity is the measure of how loud a speaker will be in decibels when 1 meter away and being driven by 1 watt of power.

Looking back at the Q Acoustics 2050i floor standing speakers we used as an example in our section on ‘power’, we can see that they have a 92dB sensitivity rating. So, with 1 watt of power (way less than any amplifier would provide), the 2050i’s would produce a sound pressure level of 92dB from 1 meter away.

So, why should you care about sensitivity? Well, it’s directly linked to how loud your speakers can get. When the distance from the speaker and power applied is the same, a speaker with a lower sensitivity would sound quieter than a speaker with higher sensitivity.

The bottom line:

It’s crucial to ensure your speakers have a high enough sensitivity that your amplifier can effectively drive them. Take a look at the listed sensitivity on your speakers and perform the basic maths above, and you’ll get an indication of whether they’re destined for each other.


It may feel as though you’ve just stumbled into an unreasonably complicated world of technical jargon, but really, matching speakers to amplifiers is largely just common sense and a little maths.

Doing a little shopping around and comparing numbers will ensure that you find a set of speakers and amplifier which not only work together, but sound amazing – and will do for decades to come, with the right care.

Of course, we’d always recommend that you hear your chosen speaker and amplifier connections together before you buy. If you’ve followed our instructions above, they should work together perfectly, but it’s also true that different amplifiers and speakers will reproduce the same source music in different ways, some of which may not appeal to your own aural sensibilities.


Q: What is the best amplifier for speakers?

A: McGary Audio SA-1 ($3,985 USD) First Watt SIT-3 ($4,000 USD) Audio Hungary Qualiton APX 200 ($4,700 USD) Merrill Audio Thor monoblock amplifier ($4,800 USD) Odyssey Audio Kismet ($4,900 pair USD) Pass Labs XA25 ($4,900 USD) Linear Tube Audio ZOTL40 ($6,800 USD) McGary Audio SA-2 ($7,985 USD) Manley Labs Snapper monoblocks ($8,400 pair USD)

Q: How to match speakers and amplifier?

A: Choose speakers that match the amplifier’s impedance level. The impedance is measured in ohms,and both the amplifier and speakers will be clearly marked with their capabilities. Compare oranges to oranges. Look for the RMS wattage of both the speakers and the amplifier,if it is given. Be aware that amplifiers will overdrive their capabilities. …

Q: How to make a simple amplifier at home?

A: How to make a simple Amplifier at home mini amplifier circuithow to makehomemadediytransistor2sc5200 transistor using npn small amplifier,transistor using mi…

Q: What AMP should I buy?

A: You can buy anything from a basic “practice” amp to a high-end, tube-powered combo that will deliver almost any tone or effect you might need or want, and it will pull double-duty as a great studio amp.