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audiophilealpha-blog · 6 years ago

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Speaker Set-Up

Properly setting up a set of speakers is just as important, if not more so, than selecting the right pair. Even high end speakers will sound uninteresting if poorly set up in the listening environment. In this project we will look at setting up speakers for stereo listening. When properly placed in a room, a pair of stereo speakers can produce a three dimensional presentation that can rival many surround sound systems.

But setting up speakers is not as simple as throwing a couple stands in the front of the room and taking a seat. Proper set-up takes time, patience, an experimental nature, and more patience. Even slight changes in tow in, distance from reflective surfaces, or pressure creating corners, can result in drastically different sound.

The Golden Triangle

A great place to start when setting up your stereo listening room is what we like to call The Golden Triangle. Assuming your room is an empty rectangular box (most rarely are), placing yourself at the apex of an equilateral triangle, equidistant from the speaker tweeters, will give you a good start at good sound.

Golden Triangle

In the sketch above, we show the speakers facing perpendicular to the front wall. That may or may not be the best, more on that later. For now however, let’s begin with the speakers in this configuration.

So now you may be wondering exactly where to place your speakers in the room. All room boundaries reflect sound, so we need to consider all reflective surfaces. Speakers can be placed both against the short wall of a room or along the wide wall of the room. Both have benefits and detriments that we shall discuss.

Golden Triangle Short Wall

Golden Triangle Long Wall

Speaker Height

First things first. Before we can make adjustments to our speakers, we first must have a means of supporting them. The goal is to set our speakers up so that the tweeters are located at the same height from the floors as are our ears, when in our favorite listening position – hopefully at the apex of your golden triangle. 🙂

So here is your first chance to utilize some high tech audio equipment that every audiophile should keep close at hand. We like refer to it as a measuring tape! Take a seat in your preferred listening position and measure the distance from your ear to the floor (inches, centimeters, millimeters, your call). Note that distance. Now, measure the distance from the bottom of your speaker box to the center of the tweeter (be careful not to damage your speakers). Subtract that number from the ear to floor number. This will give you the height of the speaker stand you should utilize for your speakers. For example, if your ear is sitting 42 inches from the floor, and the distance from the bottom of your speaker to the center of the tweeter is 20 inches, then you will want to utilize a speaker stand that is:

42 in – 20 in = 22 inches tall

A Brief Note on Speaker Stands

While we could have quite a discussion on speaker stands, for the moment let’s just mention a few basics. Try to avoid using a table as your speaker stand. Now if your stereo system happens to be at a comouter desk, this may be required, but in this example we are discussing a listening room. In this situation, using a table introduces another reflective surface that we just don’t want. Also, if at all possible, avoid placing your speakers on book shelves. Yes, I know that some are actually called book shelf speakers, but again, we are adding additional reflections. There are some ways around that issue if you have those shelves chocked full of books, but that discussion is for another day. For now, let’s go with some sturdy, movable, speaker stands. Use your imagination and budget. You can build them from wood, purchase them from a store, or grab some concrete blocks you might have handy. Do what works for you, we won’t judge!

CAUTION : Most wives frown upon the utilization of concrete block building materials in their formal living areas. Utilize extreme caution and proper protection when installing concrete block speaker stands in such environments.

If you have tower speakers, you may not need speaker stands or the stands may be quite short. Tower speakers are often an appropriate height for typical applications. This doesn’t have to be perfect, just do your best. Since you move around when listening to music, unless you utilize a lasar guided speaker height optimization assembly (I made that up, don’t go looking for those) you will never have perfect alignment in all situations. If you must be off, I suggest it is better to be too hight than too low.

Now, level those speakers up! You can utilize a standard bubble level for this, with the two dimensional version being the best option. While some speakers benefit from some tilt back or occasionally forward, we will start with our speakers level. If your speakers or stands don’t have adjustable feet, this may require some creativity on your part.

Reflective Surfaces

Now that we have identified the two standard room setups for your speakers, and have your speakers on appropriate stands, we need to consider the reflective surfaces of each room layout individually. While the ceiling and floor are reflective surfaces just like the walls, for the sake of simplicity, and since most of us can do little to change the height of our ceiling, we will first consider only the reflective properties of the walls.

Your speakers will propagate sound waves in all directions. Some will be more pronounced to the rear than others (panel or electrostatic speakers for example, vs. standard cone in box speakers), and there are variations to the side walls as well. Again for simplicity, let’s assume a generic set of box speakers with moderate side propagation, and reduced volume as we move toward the rear of the speaker, away from the axial “forward” direction of the drivers.

First we will consider the short wall placement. In the figure below, the narrower the arrow, the lower the “volume” of sound generated in direct line from the speaker to the listener. These are not drawn to any sort of scale, only as an example.

When in our listening position, we are hearing sound projecting directly out of the speakers as well as sound reflected off the walls (and yes the ceiling and floor, but again, we are ignoring that for now.

As you can see, there is a lot going on there, and it is actually even more complicated, so your ears/mind is trying to piece together a bunch of stuff.

Now it turns out that some of these reflections are good to have. Actually, all of them are good to have, but as is the case for most things, too much of a good thing isn’t so good after all. And that’s especially true for the red line. The red line is what is referred to as the first reflection. It is the reflected sound which, of the reflected sounds, packs the biggest punch when it hits your ears. As I mentioned, a bit of this is good, this is what gives your music depth and breadth. But due to some psycho-acoustic stuff that I don’t understand (not many people do actually, they just like to think they do) too intense a first reflection can muddle up your music, and leave you with an poorly defined sound stage, and lack of clarity in your music.

We have options to help resolve these problems, we can diffuse the sound reflections or we can absorb the sound reflections. When we look at these options we are looking primarily at high and upper mid range frequency sound. The lower in frequency (longer the wavelength) the more difficult it becomes to absorb or scatter the wave. For the time being let’s not worry about lower midrange and bass frequencies, we will discuss those later. What defines our sound stage, stereo image, depth, breadth, etc. is primarily the higher frequencies. So let’s discuss high frequency sound reflection modification by diffusers first.

Diffusers aren’t sound absorbers they are sound “scatterers”. Instead of absorbing the sound aves, they scatter the sound waves into multiple tiny reflections, each weakened in intensity, and many directed away from the ear. This scattering or diffusion, reduces what the ear hears due to the reflection.

Diffuser

Sound absorbers work different that diffusers. Absorbers utilize a material that traps the sound wave that hits it, keeps the sound from reflecting at all…well few things are absolute, there is always going to be a bit of reflection, and some absorbers work better than others.

Absorber

Remember in my blog introduction where I stated that audiophiles can be an opinionated bunch? Well, the use of diffusers and absorbers is one of the areas where you get lot of opinion. I have read numerous studies on the use of these devices, and everyone has their own opinion of what does the best job. Some like only absorbers in the front, some like only diffusers in the front, some want no reflection from the front wall, others want no absorption at all on the front wall. So, I am going to give you my opinion, based on my own literature research, plus trial and error experimentation. …and here it is:

Suggested Treatments

Okay, now I can hear the arguments already. How can you tell someone what to do when you haven’t heard their room? What if the room has doors and windows at the first reflection? How can you suggest this when it is an over simplification of a very complex process?! Well, all of those questions are legitimate, but I am attempting to give you a starting point for a dedicated listening room with standard sheet rock walls, and no interfering furniture, windows, doors, or spouses! From there, real life kicks in, and things get really interesting. But before we do that, let’s look at the same issues in a room with speakers set up on the long wall of the room.

To be continued…..

Speaker Set-Up was originally published on Audiophile Alpha

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audiophilealpha-blog · 6 years ago

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Introduction and Mission

The word “audiophile” conjures many images. We may imagine an ultra-rich business owner with an automated audio system worth more than most homes. We might also imagine a sweat-pant clad social dropout, holed up in his basement with home-made acoustic cladding hanging from the rafters. While both of those imaginary individuals MIGHT be audiophiles, they are at best stereotypical, and likely the exception. In reality, anyone with an interest in music or sound can be considered, at least at some level, an audiophile.

At Audiophile Alpha, our mission is to help you achieve your goal of reproducing sound as realistically a possible, without breaking the bank. We will focus on simplified explanations of scientific principles, rather than digging deep into the physics; and we will work to achieve excellent sound without expensive acoustical analysis equipment and complicated software.

As we investigate, we will occasionally look at hardware and equipment that may be of interest to you, but we will do our best to stick with options that are accessible to the average individual. In addition to electronics, we will investigate room layout options, our favorite web resources, some things we haven’t even thought about yet, and of course, music. Even an inexpensive set of speakers will sound better, when properly set up, and when playing high quality content. You don’t have to be a tycoon to enjoy great sound, you only need curiosity, a willingness to experiment, and an interest in logically applying knowledge.

Audiophiles can be an opinionated bunch, so much of what we discuss will be controversial. That’s okay! Some of the approaches we take will be pseudo-scientific at best, and those with the means will prefer more rigorous options. We cannot please everyone, but we can do our best to try. In the process we will generate dialog, and learn from one another.

What I share with you will be my understanding based on my own experiences, experimentation, and research. From there we will see where the discussion takes us. We will learn from one another and as a team, we will all gain expertise.

I hope you enjoy our content, and check back often for new, thought provoking information.

Sincerely,

Donald James, Audiophile Alpha

Introduction and Mission was originally published on Audiophile Alpha

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