This article originally appeared in StereoLife Magazine, a HiFi publication from Poland offering “A Daily Dose of Audiophilism.”

_{English version edited by Robert Schryer.}

Once we’ve figured out what type of speakers we want—their size, construction material, finish, performance, design, and price—and bought them, all that’s left is for us to carefully remove them from their cartons, connect the cables, and arrange the speakers in a way as to get the best possible sound out of them. The latter is not so easy to do, but finding the optimal positioning for our loudspeakers costs pretty much nothing but will surely provide a lot of satisfaction. All it takes is a little experience, intuition, and commitment to solve this “problem”.

One day in the editorial office, we pointed out that many music lovers don’t know how to properly position speakers in their room. Soon after, we talked about this subject with a man who knows a lot about loudspeaker design—Mateusz Jujka, CEO of Pylon Audio. We concluded that the true problem here is a lack of knowledge, so we decided to jointly prepare a comprehensive guide, which on the one hand will be a collection of tips on how to set up speakers, and on the other, an invitation to experiment, which can turn into a fascinating adventure.

It can be argued that speaker positioning is more important than the speaker itself. It’s not that difficult to position speakers, but many music lovers forget about it, postpone the matter indefinitely or neglect it because even badly set-up loudspeakers will work and play their favorite music. But the point here is not just to make the speakers emit sound, but to make them sound their best to increase our listening pleasure. What’s interesting about moving speakers around is you can can hear the effects immediately.

The correct positioning of loudspeakers is also crucial for every next step taken in expanding a hi-fi system. After all, it isn’t easy to choose an amplifier or cable if our speakers are not sounding the way they should because they’re not standing where they should be. We can compare this to how musicians are arranged on stage during a live concert. Musicians understand the importance of where they are in relation to one another, what they can see, and whether they have enough space for themselves and their instrument.

It’s also harder to place speakers when we don’t have a dedicated listening room. Most real-world rooms are used for several functions, and the sound system has to fit into this. Unfortunately, that means the system is often pushed into the background because more pragmatic concerns take over. The biggest enemy of acoustics is the minimalist fashion design pictured in advertisements for hi-fi equipment. At first glance, these rooms can look beautifully stylish, but they’re by no means designed to sound good, only to make the equipment look good. And when it comes to speaker placement, even audiophiles make the same basic mistakes, by placing speakers in the corner of the room, against the wall, or hanging from the ceiling. In addition, information in the user manual about the correct positioning of speakers is usually presented in a very simplified form, with one drawing and a few sentences about how the improper placement of speakers in a room can cause bad sound. Right, thanks a lot.

That’s why we created this guide. The subject of speaker placement and room acoustics can, of course, become so complex that it could be explored endlessly. Some experts would undoubtedly like to add their two cents to this piece, which they would consider complete only if it included scientific definitions, formulas, datasheets, computer simulations, and sample measurement results. However, we didn’t want to delve into the subject so deeply. Instead, our goal was to provide a set of essential guidelines to proper speaker placement, presented in an easy-to-understand language. We hope you’ll enjoy taking this journey with us, but before we get down to business, let’s get down to basics.

What is stereophony?

To understand why we should even bother with the correct positioning of loudspeakers, we should know what stereophony is. Sounds trivial? Unfortunately, even decades after the stereo system became popular, not everyone knows what it is or how to use it properly. So let’s get back to basics.

Stereophony is a method of recording and reproducing sound in two channels in such a way as to give the listener the impression of hearing surround sound. Stereo sound is traditionally recorded using two independent microphones for the left and right channels and transmitted through two separate channels to two different speakers. Unlike a mono recording centred on one microphone and one speaker, the microphones recording the stereo sound are put at a distance from each other—just as the speakers in the listener’s home should be positioned. Essentially, we want everything that “goes into” each microphone to “come out” of the speakers. Why? Above all, so the listener can determine the location of sound sources, such as instruments or vocals, by interpreting the difference between what’s heard by the left and right ears. The stimuli received by the brain from each ear differ primarily in their frequency characteristics and intensity, but—and this is crucial from our point of view—it’s the fact they reach the ears at different times that allows us to determine the position of the sound sources in space. Bear in mind that the human auditory system is sensitive to the smallest time shifts. After all, tens of thousands of years ago, being able to determine the direction a sound could be a matter of life or death.

We know that the average person can hear sound between 20 Hz and 20 kHz, but our knowledge of the accuracy of our hearing in locating sound sources is not easily understood. Suppose our head is 20 cm (0.2 m) wide. The speed of sound is 340 m/s. If the source is precisely to our left or right, the delay between one ear and the other is approximately 588 μs or only 0.0006 seconds! However, in reality, we can determine the position of speakers standing in front of us with a high degree of accuracy. Let’s imagine that we are in a soundproofed room, circling a person while holding a loudspeaker or a musical instrument. The average person can detect a change in the position of a sound source with an accuracy of 3 degrees, which corresponds to a delay of 20 μs (0.00002 s). Professional musicians and people with exceptionally sensitive hearing can narrow this down to 1 degree. So if you belong to this group and are sitting in front of audio equipment 3 m away from you, you should notice displacement of the speakers to the left or right by 5 cm!

Stereophony is not an unknown phenomenon to us. The term was introduced in the late 19th century by Alexander Graham Bell following an article on binaural hearing. The first practical experiment with such a system was carried out in 1881 in Paris using two telephone lines that collected two angles of sound from the opera stage. In 1938, Judy Garland performed on the first stereo recording, but Duke Ellington had actually been recorded accidentally in stereo six years earlier. To ensure that his work would be preserved, RCA Victor used two recording devices with two amplifiers and microphones placed at a distance from each other. Since records were pressed from both sources, it became possible to match the two versions and achieve a stereo effect.

You will probably think that since stereophony is an invention older than penicillin, nylon stockings, and the jet engine, humankind should have invented something better long ago. Well, yes and no. The first exciting concept to expand on this technology was quadrophonic sound—a surround-sound system that used four microphones instead of two. The first quadrophonic recordings appeared in the early 1970s. However, interest from music lovers in quadrophonic sound was negligible. The next stage was the spread of the multi-channel setup we now know as home theater. The first documented use of such a system took place in 1940, when Walt Disney Studios used up to 54 speakers during the screening of the animated film “Fantasia”. Today, 5.1 systems (using five channels and an active subwoofer) are the most popular, while a Dolby Atmos 7.1.4 system can be configured using seven speakers at the listener’s ear height, one subwoofer, and four ceiling speakers. Creating the appropriate spatial experience is handled by decoders, DSP processors, and other instruments of sound manipulation. But while being surrounded by sound and effects like bullets whizzing overhead might seem like fun, let’s remember that sound processed by complex algorithms has as much in common with the natural perception of space as cheap plastic speakers have with a hi-end tube amplifier. This is why, when it comes to music, it’s best to focus on good old stereo.

What would we see if we saw sound?

When we listen to music in a closed room, sound waves reach us directly (from the speakers to our ears) and indirectly (in the form of reflections). The reason is that the vast majority of loudspeakers generate sound in multiple directions so that only a tiny portion of their sound reaches us via the shortest route. Everything else is reflected off the walls, ceiling, floor, and all the objects in the room. Most materials absorb or reflect the waves to a greater or lesser extent. You can imagine it as if, instead of loudspeakers, there were two cannons in front of us constantly firing lots of little rubber balls. Some will hit us in the head, but most will bounce at least several, if not a dozen, times off walls, windows, and furniture. A ball that reaches our head will feel faster than one that bounces off the walls several times. In other words, when a sound wave is repeatedly reflected, it arrives at our ears with a longer delay, and at the same time, it’s strength is attenuated by objects and people in the room. This is where sound delays, caused by reflections, come from. To get a reasonably realistic picture, let’s also add other phenomena related to wave propagation, such as diffraction and interference. At the center of all this is us. By preference, sound should reach our ears as directly and untainted as possible, in the right quantity, correct proportions, with no loss of energy, and from a spatially-delineated soundstage.

What would the ideal room look like?

Before we get into placing the speakers, we should look at the listening room itself. This is usually the most immutable part of the whole puzzle. We often have no influence on the surface, shape, height, or location of windows and doors. Even when it comes to the décor or the materials used for the floor, walls, and ceiling, most of us have limited options. The theory is that the ideal listening room should resemble a miniature concert hall—well-proportioned, with angled or curved walls, constructed of materials that don’t overly reflect or absorb sounds. It should also have acoustic panels—diffusers, absorbers, polyurethane foams, bass traps, etc.—on almost all surfaces, like in a recording studio. Such a customized room is usually lined with thick pieces of foam and isolated from the outside world for obvious reasons. However, as is often the case, solutions designed for professional use do not always work at home, where the overuse of damping materials and acoustic panels can rob the music of life. Experts say that during the building or arrangement of a listening room, we should aim for natural, optimal reverberation (good listening conditions prevail in living rooms with echoes around 0.6-0.8 s).

Is my room perfect? Probably not

Every room is unique, so we should do a bit of detective work at the onset. First, we should consider the total floor space and its shape—the proportions between height, width, and length. In a small room, it will be more challenging to control low tones and recreate a spacious soundstage. In a room less than 10 m², you may be tempted to try non-standard solutions, such as hanging the monitors on the wall or using a setup found in recording studios, where the speakers are placed on the console. Although the soundstage will be less impressive, you may get better depth and imaging. It’s the opposite problem in large living rooms, where you will need larger speakers and a powerful amplifier. You will also have to find a solution to the reverberation.

To find out about our listening room, we should measure its length, width, and height. Between pairs of parallel walls, there are resonances called room modes. These are amplified frequencies because the distance between the walls coincides with the wavelength of the sound or a multiple of it. To calculate their value, let’s divide the speed of sound (340 m/s) by twice the distance between the walls. Thus, for 5 m (x2) we get 34 Hz, for 4 m (x2), 42.5 Hz, and for 3 m (x2), 56.6 Hz. We can therefore expect sounds at these frequencies to be noticeably louder than others. It is also worth comparing all three dimensions of our room with each other. For the sake of simplicity, let’s imagine that the height of our room is 1. A problematic situation will arise when the individual dimensions are multiples of each other. If the ratio of height to length or length to width of our room is, for example, 1:1, 1:2, 1:3, or 2:3, we will have a problem of induced resonances. We should, therefore, if possible, avoid square rooms or rooms that are 5 m long and 2.5 m wide and high.

How to tame the acoustics?

As we delve deeper into the subject, we realize that everything plays music in our room—not just the speakers, but, to some extent, walls, floor panels, a chandelier with glass shades. All surfaces and doors, nooks, and passageways to other rooms can also significantly impact how sound is propagated into the room. The fact is that the glazed interiors of modern flats can make life miserable for audiophiles. Unfriendly acoustics can be combated in several ways—the simplest is to fill the room with various materials and objects with damping or dispersing properties. Furniture is also a fundamental issue. In an empty room with perpendicular walls, it will be challenging to achieve the ideal effect. A possible solution for this would be to install furniture and accessories that absorb sound—curtains, blinds, a bookshelf, rug, paintings, etc. When doing so, a rule to remember is that lightweight materials tend to absorb high frequencies, while heavier and thicker ones will mainly absorb low frequencies.

Addressing first-reflection points is the most obvious starting point to room treatment. These are the places where the sound coming out of the speakers first bounces off the walls, floor, and ceiling, then goes straight to our ears and blurs the sound’s imaging. A standard room will have 12 such reflection points—two on the back wall, two on the sidewalls, and one on the floor, the ceiling, and back wall. Of course, this is a highly simplified scenario. To mark out these points, we need a mirror and the help of another person. As you’re sitting in your listening seat, ask your helper to place the mirror against the wall, at your eye level, and move it back and forth along the wall. When you see one of the speakers, mark this spot with a piece of tape. You don’t need to be accurate to the centimeter to install diffusers or absorbers at the first reflection points. (You can also use a bookcase as an acoustic panel or a thick carpet on the floor.) Controlling the first reflections should significantly sharpen the stereo image.

Speakers – the second piece of the puzzle

Before we start placing our loudspeakers, it’s worth taking a closer look at them. Speaker designs can be very different from each other—in size, type of cabinet, the way they’re ported, in their number of drivers, etc. That means we would approach the positioning of a bass-reflex design somewhat differently from that of a sealed speaker. The same attention should be given to transmission line, electrostatic, and magnetostatic speakers, and to other unusual designs. Even with a design as common as a ported one, the location and shape of the port should be considered. Generally speaking, sealed boxes and loudspeakers with a bass-reflex at the front are the easiest to set up. They can be placed directly against the rear wall, unlike a back-ported speaker, where the air has to squeeze out between the speaker cabinet and the wall. An exciting alternative is a speaker with a port facing downwards—towards the floor or plinth. Here, the manufacturer has already determined the distance between the port and opposing surface area. The user would only have to decide whether the boxes will stand on a hard surface or a carpet. Of course, there’s still the problem of finding the proper distances from the walls and the toe-in angle, but this sort of design works well in many cases.

Many audiophiles choose sealed loudspeakers for their ease of set-up and predictable, linear low-frequency response. A transmission line design is also an attractive idea. Replacing a typical port tube with a complex maze, usually occupying the entire enclosure volume, is quite demanding from a technical standpoint but it gives good results. Electrostatic or magnetostatic panels, as well as dipoles based on dynamic loudspeakers, are a subject for another article. Such designs follow their own set of “acoustical” rules.

So, if you’re looking for the easiest speaker design to set up, the safest options would be a sealed design or a bass-reflex one with the port situated on the front or bottom of the cabinet. But there’s no guarantee that if you buy one of these, everything will be fine. Every speaker model is unique, with a distinctive sonic character. We can have two three-way, floorstanding, rear-firing bass-reflex models, but if one has a lot of bass and the other a more even, fast, and detailed midband, we will set them up differently. Practice also shows that a design should not be dismissed out-of-hand based on a single aspect of its construction, such as the port’s location, nominal impedance, or the material from which the diaphragm of the woofer is made. That’s why, when it comes to speakers you’re interested in, you should read reviews about it, or arrange to audition them, or, better yet, ask if you can bring them home to listen to them in your own system.

Listening spot – the third element

It may surprise some people to learn that where our listening seat is placed has a huge influence on the sound we’ll perceive. The speakers and the listening seat are two sides of the same coin. It might turn out that sometimes it’s enough to move our armchair or sofa slightly instead of moving the speakers another twenty centimeters, which could shift the stereo effect to one side and skewer the soundstage. Our head should also be at the correct height, but avoid a high headrest that can block out ambient sounds. Another bad idea is to place the sofa or armchair against the back wall, in which case you’ll be likely to hear a lot of booming bass and a flat soundstage.

Another crucial parameter is listening height. It’s easy to forget that sound waves propagate in all directions, not just horizontally. That means that the height at which the speakers and our ears are placed in relation to each other is important. You can hear the discontinuity in focus when you get up from your couch or chair while listening to your system. Because most speakers use several drivers mounted vertically, one above the other (the exceptions being with full-range and coaxial drivers), the reference point will usually be the tweeter. This driver should be placed at the height of our ears. If this isn’t possible to do, our head should be placed slightly higher than the tweeter, or at least this is the recommendation of many speaker manufacturers. Other options include changing listening seats, having monitor speakers placed on height-adjustable stands or spikes, or, if the speakers are floorstanders with tweeters aimed above the ears, using longer spikes or granite slabs under the speaker cabinets.

Part 2 coming soon…

Article created in cooperation with Pylon Audio.