Back thataway several posts I opined that the most important component in your audio system is the recording engineer responsible for capturing the original musical performance. It’s a fact, kids. So now what’s next? Surely it’s time to think about D to A converters, or low distortion speaker cables made only with organic oxygen free copper, or yada yada yada. Nope. The second most important audio component in your system is your listening room.
Since the goal is (repeat again after me) to produce the most believable sonic image of the original, we need to be able to transmit this sound to your ears from your speakers in the most accurate and uncolored way possible. This means we need to keep from adding or subtracting any sound levels that were not part of the original. The truth is, our ears are not too smart. But our brains will instantly call fowl if the spectral balance is messed up.
So how do we go about dealing with this? There are several things to consider about the room (and the space within it) which will have a huge effect upon how convincing the sonic image is to our brains. Let’s take them one at a time.
First, we need to understand a bit about room acoustics. Walls are required in most rooms. Sonically they can do good things or bad things. Which they do depends upon their construction, dimensions, and placement relative to one another. I will spare you the math associated with how to answer this question in favor of some general do’s and don’ts:
- Parallel walls are bad;
- Curved or non parallel walls are good;
- Sloping ceilings are good;
- Sloping floors are good for sound but can be dangerous;
- Avoid a room where walls (including the floor and ceiling) are equal or multiples Eg: 10x10x10 is the worst possible; 10x20x10 is nearly as bad;
- Having large heavy objects in the room is good (unless they are the listener);
- Walls should be rigid. 16″ on center studs and drywall is not a wall at 40 Hz;
- Room size is also dependant upon your speakers and available amplifier power. More on this later too;
OK Second, we need to determine the optimal location for your speakers. The distance between your speakers and a rigid surface (such as a wall or floor) will have a big effect upon bass response. Um, no. The speakers will respond almost the same no matter where you put them. What I should say is, it will have a big effect on how loud and the how smooth the bass sounds to you depending upon where your ears are in the room. Again there is a ton of math you can use to determine this but for most folks there are practical considerations about where your speakers end up in your home environment (such as marital bliss). So more do’s and don’ts:
- Putting speakers deep in corners of the room is very bad. It’s scary in there for them;
- Sitting on the floor is bad (if you are a speaker);
- Speakers need some distance between them. For now let’s just consider a classic 2 channel stereo system. A good starting point is the distance between them should be roughly the same as the distance to your ears;
- Let your speakers away from the wall. They like to join the party;
- Try to maintain an equal distance between each speaker and an adjacent wall. Symmetry is good;
Remember: All this is primarily about the bass reaching your ears. For a simple classic two speaker system, it matters not how much you spend on “technology”. No amount of equalization will cure a bad listening room acoustic problem. The uniformity of amplitude across the low end of the spectrum as well as the absolute low frequency limit will both be highly influenced by the room shape, construction, contents, where you are, and where your speakers are in it. This is laws of physics folks. Get used to it.
Middle and high frequencies are a different problem for room design. They react to their surroundings in quite a different way from the low end. Bass energy tends to go through surfaces easily. Middle and especially high frequencies are easily reflected by hard surfaces and much more readily absorbed especially by soft materials such as rugs or drapes. In general, at least some broad surfaces should have damping (rugs, drapes, wall hangings). The exact amount of these soft acoustically absorbent materials will depend upon your speakers and the size of the room. Too much softness and the sound will lack openness and sparkle. Too little softness will mean unpleasantly bright and hollow audio. Given the right balance, the sound from the loudspeakers will reach your biotransducers (ears) in tact and with the least amount of coloration from your listening room. Listening trial and error will carry the day on this one.
Next time: Speakers 101