The synergy between your loudspeakers and stereo amplifier is perhaps the most crucial aspect to consider when setting up your hi-fi system.
As a result, it’s also one of those decisions that require deep research and multiple trials if you want to reach optimal results.
In this article, I will guide you through the best practices when buying an amplifier to match your speakers, explain the terminology involved in simple terms, and help you choose compatible audio gear with confidence.
Why you should trust me
I’m a music producer and audiophile obsessed with the intricacies of sound.
After years of working in the music industry, I developed a taste in high-fidelity audio, starting by upgrading my parents’ old Aiwa sound system until I reached the perfect sonic experience.
For the last couple of years, I’ve shared tutorials and reviews on how to get started in the world of hi-fi, with the hope of introducing listeners of all ages to the world of audio fidelity.
Contents
Use these links below to navigate to the desired section of the article.
- What are the key factors to consider?
- How to choose an amplifier: A step-by-step guide
- A few examples of heavenly matches
- Frequently asked questions
Key factors
To find out whether loudspeakers and a power amplifier can deliver optimal results, there are certain specifications we need to understand and analyze.
Especially when creating a hi-fi system using multiple brands, it’s fundamental to pay attention to these specs, which you can always find in the tech specs of loudspeakers and power amplifiers.
Impedance
Impedance is the electrical resistance of your audio gear and is measured in ohms (Ω).
As a rule of thumb, it’s good practice to choose a power amplifier whose impedance is equal, or slightly lower, to the total impedance of your loudspeakers. Power amps have an impedance of 4, 8, or 16 ohms.
It’s still OK to connect a power amp with an impedance lower than the loudspeakers’, so long as you don’t have to crank up the volume to the amp’s limit.
These days, most amplifiers come with a list of compatible ohms, making it easier to match them with loudspeakers without worrying about impedance.
Power
Power, measured in watts, defines how much power an amplifier can send to the speakers and how much power the speakers can sustain.
However, we need to get more into detail as there are different types of “power” you need to be aware of when choosing a power amp.
- Peak power is the maximum power a speaker can sustain without getting damaged.
- Continuous power is, you might guess, the power a speaker can sustain during regular operation.
You’ll find both specs on your amplifier, so matching the power of speakers and the amp will allow you to get the most out of your hi-fi system.
A common misconception is the belief that wattage is what defines the system’s loudness, but that’s actually determined by sensitivity, which is not strictly connected to power.
Sensitivity
The sensitivity of a speaker will indicate how loud it can get with a one-watt input and measured from one meter away. Sensitivity is measured in decibels (dB).
Essentially, higher sensitivity means speakers will require less power from the amplifier to sound louder.
Amplifiers provide more than one watt because their power output has to double to increase the sound pressure of 3 dB.
Furthermore, the distance from the loudspeakers decreases the sensitivity dramatically, meaning you’ll need more power depending on the environment’s size.
Number of channels
The number of channels in an amplifier indicates how many separate audio signals it can handle.
For instance, a stereo amplifier has two channels, while a multi-channel amplifier can manage more, which is essential for setups like surround sound systems.
Connectivity
Finally, consider the types of connectivity options the amplifier offers, such as RCA, XLR, HDMI, optical, and wireless options like Bluetooth or Wi-Fi, depending on your specific needs and setup.
How to choose an amplifier: A step-by-step guide
Here’s how to find a matching amp for your speakers:
- Know your speaker requirements
- Match the impedance
- Choose the right power output
- Consider the number of channels
- Don’t forget connectivity options
- Think about future upgrades
Step 1: Know your speaker requirements
Before you buy anything or do anything, check the specifications of your speakers: power handling capacity (both peak and continuous), impedance, and sensitivity, as we discussed earlier.
This is a crucial step, as getting an amp that’s not perfectly compatible with your speakers might result in damaging your gear or having your audio system underperform.
Step 2: Match the impedance
Get an amplifier with an impedance rating that’s in line your speakers’, which means the speaker impedance should be equal to or higher than the amplifier’s to avoid overheating and damage at high volumes.
Step 3: Choose the right power output
Check the amplifier’s power output and make sure it matches the continuous power rating of your speakers.
A good rule of thumb is to choose an amp that can provide at least twice the continuous power rating of your speakers. The extra headroom will give you a clean and undistorted sound.
Step 4: Consider the number of channels
How many channels do you need? A stereo system needs just a two-channel amplifier to work. If you’re building a home theater, you’ll need an amplifier with more channels to create a surround sound system.
Step 5: Don’t forget connectivity options
Ensure the inputs and outputs on the amplifier are in line with what you need to upgrade your sound system.
If you use digital sources, the amplifier should have all the necessary digital inputs, like optical or HDMI connections, as well as Bluetooth and Wi-Fi.
Step 6: Think about future upgrades
Get an amplifier that can enhance your listening experience for years to come. If you want to expand your audio system, choose an amplifier with additional channels.
One day, you might want to upgrade your system and reuse your existing gear in other ways. In that case, an amp with various connectivity options would be the best option.
Examples
It’s time to give a few examples of heavenly matches.
Here are three examples of amp and speakers that notoriously work well with each other and fall within the same price range.
To find out more about each of the items discussed below, I recommend you check out my previous articles on the best integrated amplifiers, the best bookshelf speakers, and the best floor-standing speakers.
Budget: Elac Debut 2.0 B5.2 + NAD D 3020 V2
The Elac Debut 2.0 B5.2 has a sensitivity of 86 dB and an impedance of 6 ohms, so a good, budget-friendly amp that’d work well with them is the NAD D 3020 V2, which offers 30 watts per channel at 8 ohms.
I spoke highly of both Debut 2.0 B5.2 and D 3020 V2 in the past, and together, this combo brings to life an incredible sound, considering the total cost of amp and speakers is roughly $800.
Mid-range: KEF LS50 Meta + Naim Uniti Nova
The KEF LS50 Meta has an impedance of 8 ohms and a sensitivity of 85 dB, while the Naim Uniti Nova provides 80 watts per channel at 8 ohms.
This combination offers the best value for money, making the most of the superb LS50 Meta thanks to the extensive connectivity options and detailed audio reproduction provided by the Uniti Nova.
High-end: Wharfedale Elysian 4 and Mark Levinson No 5805
With an impedance of 4 ohms and a sensitivity of 92 dB, the outstanding Wharfedale Elysian 4 requires a powerful and high-quality amplifier.
If you want to make the most of this high-end speaker, my recommendation is the Mark Levinson No 5805, which provides 125 watts per channel at 8 ohms.
This amp offers ample power, headroom, and exceptional reproduction quality, enhancing the immersive and dynamic characteristics of the Elysian 4.
Just make sure you have a room large enough to justify the volume (and financial investment) this setup can offer.
Frequently asked questions
Do all speakers need an external amplifier?
No. Active speakers have built-in amplifiers, while passive speakers require an external amplifier to drive them.
Can an amplifier make my speakers louder?
An amplifier can increase the volume of your speakers when it gives them more power, which translates into higher sound pressure levels.
Does an amplifier affect the sound quality of my speakers?
Yes. A high-quality amplifier will provide power and detail and avoid distortion, which will make your audio system sound better.
How do I match vintage speakers with a modern amp?
You always need to check that the impedance and power ratings are compatible. Vintage speakers can have different sensitivity and impedance levels, so choose an amplifier that can drive them without causing damage.
Note: You can find the impedance and power ratings information on the back of most vintage speakers.
How can I test if my amplifier and speakers are a good match?
Play music you know by heart at various volumes and analyze the distortion, clarity, and balance at each volume level. Make sure the amplifier doesn’t get too hot, and listen carefully for any signs of sonic artifacts.
What are the most common mistakes to avoid?
As long as you remember to match impedance and sensitivity ratings, you’ll most likely keep your speakers safe and won’t experience distortion. Providing your speakers with adequate power will make them shine, so always check the specifications of both speakers and amp to ensure they’re a match.
Final thoughts
Let’s summarize the most critical aspects discussed in this article.
A power amplifier makes the line-level signal louder and is placed between the audio source and the passive loudspeakers.
There’s no one-size-fits-all solution when it comes to matching amplifiers and loudspeakers.
However, there are specific parameters to follow to ensure they’ll work well with each other and you won’t damage audio gear: impedance, power, and sensitivity.
All specifications are included in both loudspeakers and amp’s tech specs, so make sure they’re compatible before purchasing them.
The speaker’s continuous power rating plays a crucial role here, and I’d recommend you get an amplifier that can provide twice that much power per channel, which will leave enough headroom for peaks and won’t cause distortion.
Choose a power amplifier and loudspeakers that’ll fit the environment they’re placed in.
If your hi-fi system is in a large room, but you’re using an underpowered amp, your gear will overheat, and you’ll start hearing clips and distortion.
On the other hand, if the amp is too powerful, the speakers will not be able to sustain the heat energy and get damaged.
