What is a Monitor Speaker?
Those new to audio production will undoubtedly find themselves with information overload. Upon entering this new territory of the fusion between technology and creativity, thousands of questions immediately surface. Each answer produces even more questions, something akin to the Hydra of Greek mythology. Cut off one head, and two will grow in it’s place. A common question asked by new and aspiring producers and engineers is “What is a monitor speaker?” And if you’re here, there’s no doubt you want to know too. In this informative article, we’ll cover everything you need to know about monitor speakers, also commonly called studio monitors. Let’s get started.
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Last Updated: April 11th, 2020
Overview
In a nutshell, monitor speakers are loudspeakers that we use specifically for audio and music production. They’re called monitor speakers or studio monitors because they’re used for monitoring – critical listening during recording, mixing, and mastering. Monitor speakers are an essential part to any hobbyist or professional recording setup. Without these specialized speakers, you’d have a hard time creating a great mix, although it can be done with high-quality studio headphones.
A pair of PreSonus Eris E5 studio monitors.
Differences Between Monitor Speakers & Home Audio Speakers
Monitor speakers are intended to be used in recording studios and home studio setups for music and audio production. It only makes sense that they will have different design features than speakers you’d buy for casual listening and audio playback for your computer and home theater. The purpose of the studio monitor is to create as accurate of a representation of the audio signal as possible. In contrast, home stereo speakers are more geared towards creating a pleasant and immersive listening experience.
Frequency Response & Phase Linearity
Frequency response refers to how the monitor or speaker will change the way the audio signal sounds. Many audio devices, including microphones and audio interfaces, will have their own frequency responses. Studio monitors and monitor speakers are all designed to have as little of an effect on the audio signal as possible. The term for this is “flat” in reference to the frequency response curve.
The frequency response curve shows how the monitor alters the sound as a function of frequency. Therefore, a flat curve means there is no change in the way the monitor reproduces the input signal. In reality, a perfectly flat frequency response is impossible. But engineers do design monitor speakers to be as flat as possible within their budgetary constraints and the current technological limitations.
Sound engineers design home audio and casual listening speakers for a pleasant listening experience, not for raw accuracy. Usually, their frequency response curve exaggerates bass and treble frequencies. This makes the audio sound subjectively “better” to the listener, and makes them more likely to buy and enjoy the product. However, due to a V-shaped frequency response that is far from flat, home stereo speakers provide an inaccurate representation of the input audio signal.
Phase linearity is another important consideration. This refers to how the monitor alters the phase of the signal’s constituent frequencies across the spectrum. A linear phase relationship means that the monitor shifts the phase of all audio frequencies across the spectrum by the same amount. This reduces or eliminates phase distortion, which adds to the inaccuracy of the monitor.
Active vs Passive
Home audio speakers are usually passive, while studio monitors are almost always active, meaning they have a power amplifier built into the speaker. Some utilize biamplification and have a separate amp for each driver. The tweeters and woofer will each have their own dedicated power amp.
Biamplification allow for better crossovers since they allow for steeper filter roll-offs. This makes the separation between frequency ranges of the woofer and tweeters more defined, and reduces doubling up of frequencies. The overall result is a more accurate reproduction of the audio.
Stereo Imaging, Soundstage, & Audio Fields
Another important characteristic that monitor speakers have is their ability to produce a stereo image. Stereo imaging refers to the perceived spatial locations of sound in 3D. Monitor speakers and studio monitors are all about accuracy. Engineers design them to reproduce the stereo image with precision. This makes it easy to pinpoint and adjust the placement of sounds in the stereo field during audio production.
Engineers design monitor speakers to fit 3 main categories that effect the reproduction of the audio field: near field, mid field, and far field. Let’s break these down.
- Near field
- designed to be placed between 3 ft and 4 ft away from the listener
- room acoustics have less of an effect
- great for budget or home studios, and used by pros too
- Mid field
- designed to be placed further from the listener in medium to large studios
- more expansive soundstage than near field monitors
- room acoustics have a moderate effect
- Far field
- designed to be placed far away from the listener
- the most expansive soundstage of all 3
- room acoustics have the biggest effect
Placement & Isolation
Where you place your monitor speakers can make or break your studio setup. Here are several things to consider when placing your near field monitor speakers in your studio.
- the height of the tweeters should be at ear level
- make sure the monitors are symmetrically placed – equidistant from walls and from each other
- form an equilateral triangle between the listener and the two monitors
- monitors should fire directly at the listener’s head
- use isolating stands or acoustic foam to decouple the monitors from the surfaces they’re resting on
- place monitors 3 to 5 ft away from walls if possible
- if your room is rectangular, place monitors along one of the short walls
Create an equilateral triangle between your head and the left and right monitors (L & R from POV of listener).
Specifications
The last thing we’ll talk about are some common specifications and technical data you’ll run into when you’re researching or shopping for studio monitors.
Woofer Cone Size
This refers to the diameter of the woofer cone. The woofer cone is the largest driver on the monitor, and it’s responsible for replicating lower and mid-range frequencies. Woofer cone size is important to consider, because the larger the woofer cone diameter is, the better the speaker will be at reproducing lower frequencies.
Some common woofer cone sizes are 3.5 inch, 4 inch, 4.5 inch, 5 inch, 7 inch, and 8 inch. Mid and far field monitors can have even bigger woofer cones since they cover larger distances and need more power behind them.
For studio monitors, it’s recommended to have woofer cones of at least 5 inches in diameter. But that’s not always feasible, especially if you’re in a smaller room. In that case, you may want some smaller monitors. As a rule of thumb, larger woofers cover longer distances, so keep your acoustic space in mind.
Full Disclosure: As an Amazon Associate, I earn from qualifying purchases. Buying through any of the links below will earn me a small commission at no extra charge to you.
Some popular 5 inch near field monitors:
Some popular 7 inch near field monitors:
Some popular 8 inch near field monitors:
Max SPL
Max SPL is a measurement of how loud your monitor speakers can get. It’s measured in a unit called dB SPL (decibels sound pressure level). Max SPL is more important for mid and far field monitors because they need to be louder to cover the larger distances between them and the listener. Mixing at a very low volume level is always a good idea, so if you’re using near field monitors, max SPL will be just a small consideration.
Frequency Range & Response
We touched on frequency response earlier, but a common spec you’ll see along with the frequency response curve is the frequency range in Hertz, Hz. This is telling us the highest and lowest frequencies that the monitor is capable of producing. Human hearing is limited to the range of 20 Hz to 20 kHz, so shoot for a monitor that is capable of producing sound throughout this range.
More important than the frequency range is the variation of levels within that range. Commonly, you’ll see something like 45 Hz – 23 kHz +/- 3 dB. This means that across that range, the maximum variation from the baseline level for any given frequency along the response curve will be 3 dB higher or 3 dB lower. 3 dB of variation or less in either direction is a good starting point if you’re looking to make a purchase.
Total Harmonic Distortion
All audio devices have their own added noise due to circuit elements and other physical limitations. Monitor speakers add distortion through their amplifiers. THD is the ratio of added unwanted noise and distortion to the original signal. You’ll usually see this displayed as a percentage, for example 0.5% THD+N. Home audio speakers have much higher THD figures – just another reason to not use them for audio production.
