Do Amplifiers Improve Sound Quality?


From recording, mixing and mastering to formatting and reproduction to end listening environment and playback system, numerous devices affect the overall audio/sound quality. An amplifier is a vital component of a sound system, but will the amplifier affect the quality of the audio and the resulting sound produced by the speakers or headphones?

Do amplifiers improve sound quality? Amplifiers ideally amplify audio signals linearly and, therefore, do not technically improve or worsen sound quality. However, less-than-ideal amplifiers, amp settings and amplifier-speaker combinations may worsen sound quality. Amps are nevertheless needed to drive speakers and headphones properly.

In this article, we’ll discuss the role of amplifiers in a broader sound system and how they may (or may not) affect the actual quality of the audio they amplify.


Audio Quality & Sound Quality

The definitions of the terms “audio quality” and “sound quality” are somewhat elusive.

Audio quality, generally speaking, refers to the subjective and objective characteristics of an audio signal. Factors such as frequency response, dynamic range, noise, distortion and stereo width play roles in determining audio quality.

Sound quality, generally speaking, refers to the timbre of characteristics of a sound. When it comes to audio playback (from speakers or headphones), sound quality often refers to how the audio is reproduced as sound. It answers how the audio itself sounds and, more relevantly, how accurately the playback system can reproduce the audio.

The short, simple answer to “do amplifiers improve sound quality?” is no. An amplifier is designed to increase the audio signal levels. However, it is not intended to objectively or subjectively improve the recorded audio nor the reproduction of such audio.

While an amplifier plays a vital role in helping to achieve a louder playback volume, it does not have nearly as strong an effect on the quality of the sound as other components in your audio system. Better quality speakers, for example, will have a much more noticeable impact on overall sound than even the most expensive amplifiers.

On the other hand, while an amplifier may struggle to improve sound quality without the support of the remaining components, it does have the power to make the sound quality worse even if you are using a top-of-the-range speaker system.

If poor sound quality is caused by the amplifier’s weak components and output signal(s), upgrading the amplifier will improve the quality of the sound.

Matching the amplifier and speakers for ideal sound reproduction is a science in and of itself.

When choosing an appropriate amplifier for our speakers (or vice versa), we must consider the specifications of the amplifier and speakers. Primarily, we should be looking for compatible impedance, power and sensitivity ratings along with the amplifier’s channel count.

To learn more about matching speakers and the important specifications listed above, check out the following My New Microphone articles:
Why Do Speakers Need Amplifiers? (And How To Match Them)
• What Is Amplifier Impedance? (Actual Vs. Rated Impedance)
• The Complete Guide To Speaker Impedance (2Ω, 4Ω, 8Ω & More)
• Complete Guide To Speaker Power Handling & Wattage Ratings
• Full Guide To Loudspeaker Sensitivity & Efficiency Ratings

The main takeaway here is that a high-quality amplifier can do little to improve sound quality unless other items are also upgraded, but a poor-quality amplifier can make sound reproduction worse.


What Does An Amplifier Do?

To better understand the impact of an amplifier, it will help to know what they are designed to do. As previously discussed, an amplifier, put simply, boosts an audio signal. It does so by using electricity (typically from the power mains) to apply gain to the signal.

There are various types of audio amplifiers including preamplifiers, power amplifiers and integrated amplifiers (a combination of a preamp and power amp).

Related article: Why Do Audio Amplifiers & Preamplifiers Need Power To Work?

There are also various signal levels in the world of audio.

Most recorded audio and live audio mixes are set to be at line level (+4 dBu or 1.228 VRMS). The main exception being vinyl records and their players, which are generally at phono level (-60 dBu or below). Mic level is also below line level.

To learn more about decibels, check out my article What Are Decibels? The Ultimate dB Guide For Audio & Sound.

A preamp will effectively boost lower signal levels up to line level for mixing and recording. You’ll find plenty of phono preamps and microphone preamps on the market for this purpose.

However, to properly drive speakers, we need something stronger than line level. Sending a line level signal to a pair of speakers will barely produce any sonic results, if at all. We need what is aptly referred to as “speaker level” signals, which are typically over 10 V but can reach measurements of 100 volts or more in large concert environments.

Speaker signals are often measured in watts (electrical power). As mentioned earlier, power amplifiers and speakers will have power ratings (output and handling, respectively) to help users understand their capabilities.

For more information on a power amp and speaker specifications, check out the following My New Microphone articles:
Complete Guide To Power Amplifier Specifications & Data
Full List: Loudspeaker & Monitor Specifications w/ Examples

This is where a power amplifier comes into play. The amplifier converts low voltage electrical signals produced from the source equipment by increasing its strength significantly so that it can effectively drive a pair of speakers to produce sound.

With this in mind, it is easy to see how an amplifier can not improve the sound of a poor audio source. It will also be challenging to create a better sound if the speakers that receive the amplified signal are unable to reproduce the nuances of the amplified audio signal.

For my opinion on the best power amplifier brands, check out my article The Top 11 Best Power Amplifier Brands In The.


A Note On Distortion

If the input signal remained constant at all times (direct current), the job of an amplifier would be very easy. However, where sound is concerned with varying pressure in the environmental medium, audio signals must be AC (alternating current) by necessity. As the instantaneous voltage/power fluctuates within an audio signal, amplification may cause distortion, particularly at the relatively high values of voltage/power.

All amplifiers have a maximum in terms of how much output they can produce. Surpassing such output will effectively distort the output signal. Doing so repeatedly over an extended period (or a short period in particularly bad cases) can cause damage to the amplifier and speakers.

There may be times when distortion is created deliberately; take, for example, a speaker system designed to offer extra perceived bass (by distorting the low-end and, thereby, producing audible harmonics of the bass in the midrange).

In the majority of cases, however, the distortion is uninvited and can become distracting or even spoil the intended sound. A poor-quality amplifier is likely to cause greater distortion leading to a reduction in the sound quality.


Can An Amplifier Improve Sound Quality?

Although an amplifier alone can not improve sound quality, it can positively affect other components of the sound system. A high-end, component-compatible system will work more efficiently, improving the quality of the sound overall.

High-end amplifiers produce better linearity, meaning their output is unchanged from the original signal they receive, apart from being amplified. Amplifier gain is another factor that can cause some sounds to be better amplified than others. The cleaner the gain, the less noise will be introduced into the system and, therefore, the output of the speakers and/or headphones.

To learn more about headphone amplifiers, check out my article What Is A Headphone Amplifier & Are Headphone Amps Worth It?


Additional Factors To Consider

Here are a few more key factors to take into consideration.

The selected speakers need to be powerful enough to respond to the signal from the amplifier, usually by having a high enough power/wattage rating to cope with a boosted signal. In addition, the type of wire used to connect speakers to the amplifier will also need to be made of a thick enough gauge to transfer the signal effectively.

The audio source is also an essential factor to consider when aiming to improve sound quality. If your playback device isn’t generating a quality signal from the outset, even the best amplifier in the world won’t manage to improve the quality by boosting its power. It’ll only act to amplify the poor quality of the audio signal.


How To Improve Sound Quality

So if an amplifier won’t necessarily improve sound quality, what will? Again, this is all relative. As a general principle, the best equipment will not “improve” sound quality at all. Rather, it will reproduce the audio signal with perfect accuracy. Of course, this is an ideal scenario and not absolutely possible in practice (though we can get close)!

So then, in this section, we’ll discuss the factors that will improve sound quality in the context of relativity. Improving the following factors will undoubtedly enhance the potential sound quality of the system.

Speakers

One of the best ways to improve sound quality is to replace lower-quality speakers with higher-quality speakers rather than the amplifier itself. The best speakers can reproduce sound from their input signal very accurately, with no distortion or alteration.

High-end speakers will typically have an accurate frequency response or, alternatively, a frequency response tuned to enhance the non-linear perception of the human ear.

Of course, top-of-the-line speakers only perform optimally when combined with an amplifier strong enough to drive the speakers correctly. A weak or damaged amplifier could be the reason why your sound quality might suddenly diminish.

There are plenty of great speaker brands on the market. For my opinion on the best-of-the-best, consider reading the following My New Microphone articles:
Top 10 Best Loudspeaker Brands (Overall) On The Market Today
Top 11 Best Home Speaker Brands You Should Know And Use
Top 11 Best PA Loudspeaker Brands You Should Know And Use
Top 11 Best Studio Monitor Brands You Should Know And Use
Top 11 Best Subwoofer Brands (Car, PA, Home & Studio)

Speaker Position

Speaker positioning is crucial for sound quality in any given listening environment. It’s important to remember that the space between the listener and the speakers is part of the listening experience.

Two (or more) speakers work together to create an excellent stereo sound, but the distance between the two speakers will play a major role in how those speakers end up sounding at any particular point in the room. This is equally, if not more important, for surround sound formats.

The ideal position for speakers is precisely equidistant from the listener, but this is impossible to achieve in a large room with several different listeners. If the speakers are not equidistant, the sound will appear less natural.

Positioning speakers on the floor or too close to walls will also affect speaker output. For better fidelity or an authentic recreation of the original signal, speakers should be placed on a stand with fewer surfaces in the immediate vicinity.

Room Acoustics

The acoustics of a room can have a powerful impact on how crisp and clear your sound quality continues to be.

The dimensions of the room and the objects within the room will have natural resonances that, when not dealt with properly, will cause build-ups of certain frequencies and cancellation of others and even disturbing rattling, especially when the speakers are driven loudly.

Fortunately, the shape of the walls or objects in the room can also diffuse sound waves, thereby improving the response of the room.

Learning how to work with your room layout can improve your sound quality significantly.

It is also essential to consider the size of the room. Large rooms, when untreated, will produce longer reverberation times. Small untreated rooms will cause shorter reflection times, often causing an unwanted slapback delay sound. Reverberation is the amount of time take takes for a sound to drift away.

Audio Format/Quality

Choose audio formats that sound the best. Lossless digital formats such as FLAC (Free Lossless Audio Codec), for example, are of higher quality than lossy compressed formats like mp3 (MPEG-1 Audio Layer III). The quality of streaming audio is notoriously bad, though some services offer hi-fi formats.

Equalization

Equalization, most simply, is a process of adjusting the gain of individual frequency bands within an audio signal. Many audio players, and even some amplifiers, will offer an EQ.

With the ability to adjust the relative levels of bass, midrange and treble (or more sophisticated bands), a listener can dial in his or her preferred balance. This can also help make up for lacklustre response in specific frequency bands in a less-than-ideal system.

To learn more about audio equalization, check out my in-depth article The Complete Guide To Audio Equalization & EQ Hardware/Software.


Conclusion

A high-quality amplifier will help all other components in the audio system to work effectively and therefore ensure the maximum quality of the sound produced. These essential devices allow us to drive the speakers (or headphones) properly for our listening pleasure.

To improve sound quality, think about the amplifier and the speakers as a cooperative team. The right combination can offer crispness, tone, and clarity, as well as impressive volume. Whether you are looking for a super-speaker to boom out tunes at a party or just wanting to relax with gentle music in your headphones, selecting a suitable amplifier can mean the difference between perfect sound quality and a poor listening experience.

Arthur

Arthur is the owner of Fox Media Tech and author of My New Microphone. He's an audio engineer by trade and works on contract in his home country of Canada. When not blogging on MNM, he's likely hiking outdoors and blogging at Hikers' Movement (hikersmovement.com) or composing music for media. Check out his Pond5 and AudioJungle accounts.

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