The sound is simply to fluctuations in air pressure (or otherwise), usually generated by mechanical vibrations from a source that can be perceived by our ears and interpreted by our brain.
The noise is unwanted sound, and usually has a connotation of "disgusting." The concept is ambiguous, since both concepts of "unwanted" and "bad" are subjective. In the area where we are talking about computers, we can consider that all the sound they emit is not desired, so discuss either of sound or noise.
The silence is the absence of sound. This term is also somewhat ambiguous in English, since it also speaks of something is silent "if it is noisy", ie not necessary the total absence of noise for something to be silent. English are more precise terms, both translated as silent, silent and quiet: silent is the "silence" while quiet would be equivalent to "not make much noise." Talking to these terms in English ... PC could be "silent" or not, there is no middle, a PC can not do more or less "silent", it simply is or is not. However, a PC it can be more "quiet", this term provides greater flexibility. And yet, there is always the subjective problem of defining when a PC is no longer "quiet" or not. In Overall, the level of quiet PCs are used and QuietPC SilentPC concepts related to these two terms.
A SilentPC is a PC that does not make any noise. This is practically impossible, stick your ear to the computer always some noise, such as coils of power always make a little noise and small. For this reason, it tends to change the definition and implementation of a distance. It is generally held that a computer is a SilentPC if we can not listen from a distance of 1 meter. This makes the definition a bit less perfect, since there is a degree of variation in what can be heard at a distance of 1 meter, depending on each person's hearing sensitivity and background noise environment in which the computer is.
QuietPC A PC is a low noise we perceive. Unlike a SilentPC, a PC that is impossible to hear, a QuietPC is a PC that, although we hear it, does not make much noise. This concept is very subjective, since what is silent for some people, others may find it noisy.
Therefore, the basis of these definitions are not very strong ... Still commonly used in the field of PCs silent, and in colloquial terms we say that a SilentPC is a PC that can barely hear some distance (1 meter) in a quiet environment, and a QuietPC is a PC that most people do not seem very loud.
We have seen that the concepts of noise, silence, and SilentPC QuietPC are not very precise and bounded, so let's see if you can physically quantized.
As mentioned, the sound is waves of pressure. The pressure can be measured physically, and the pressure unit in the international system are the Pascal (Pa) derived from Newtons (units of force) per square meter (unit area). Using this
As you can quantize audio in pascals, but there is a problem, is that not all pressure waves are perceived by our ears. And not all ears are the same, some people can hear sounds of a certain intensity that others can not. Convention is used as a standard, and is considered the threshold at 20MPa (millipascals).
Sound is measured in a unit on these 20MPa, the dB or decibel , which also uses a logarithmic scale. A bel is 10 decibels. The mathematical expressions of the two concepts are:
decibel:
dB = 10 * log 10 (P / 20MPa) bel:
B = log 10 (P / 20MPa) where P is the measure of the pressure being measured.
In addition, we must consider some things. Depending on the frequency of sound there are sounds that can not be heard (very high or very low frequencies), and it is also filtering units of measurement. Depending on the isophonic curves are used to filter frequencies are defined dBA, or DBB dBC . The most widespread of these three are the dBA , also called decibels hearing.
And if it was not enough, consider different possible measures that can make the sound. If we consider the total sound generated by a particular source, in general talk about sound power (measured in dBW), but in practice it is very difficult to measure. The sound generated by this source will be distributed in space, and usually measuring devices that can be used (sound level) can be measured at a single point. This measure is a single point known as SPL (sound pressure level), and as we normally see in the data sheets from manufacturers such as dBA (actually dBA SPL).
In short, the sound can be quantized and measured in dBA SPL. But to measure the sound of something (eg a computer) we find these ambiguities:
- is not the same as taking an inch on your computer, take the step to 10 meters. Any measure SPL should specify the distance that has been measured. Still, the same distance from the computer can get different values \u200b\u200bdepending on the position in which action is taken. Standard is generally seen as taking the measure to 1m.
- For a correct measurement of noise from a computer, we should completely isolate the noise from the rest of the environment, and this is very difficult. 10dBA loss is virtually impossible even in an anechoic chamber designed for this purpose. So there will always be added noise in the measurements, and this noise will vary depending on where you have been tested.
- The SPL as a point does not contain information on the type of frequencies containing the signal being measured. It can be a very serious signal or a very sharp signal, and having both the same as SPL, it can be very annoying and the other no change.
is, the SPL as we think of it as a picture of an object from a certain point, we used to get an idea of \u200b\u200bhow it is, but does not provide us any information of that object. And manufacturers do little to improve the situation, using marketting policies that tend to take advantage of these ambiguities, completely baffling to many users who are unaware of these limitations of the measures dBA SPL. Many manufacturers offer dBA measures entirely unrealistic (7dBA are fans or the like, which are impossible), that is to say how they have obtained (perhaps by subtracting the ambient noise of your testing environment ?...).
Therefore, we conclude again, even after trying to quantize things scientifically, that the measures we can find the sound of a computer are ambiguous and depends on many factors measurement. Are useful to compare measurements in the same environment and under the same conditions, but little else. We can not read a measure of a website maker, measure and compare ourselves to our team.
words, all concepts that we discussed: noise, silence, SilentPC, QuietPC, measured in dBA, etc. concepts are ambiguous, and we must be careful when using them. There is always a subjective component definitions. And the measures are always relative, we must consider under what conditions have made the measurements. Noise
computer first thing they ask is why we want a computer without sound. In the daily use the computer without consciously realizing that continuous noise it produces. But I think we have all felt that feeling of rest and relaxation you feel when you turn off your computer and stop listening to the noise it produces. It's much more rewarding to work (or play) with a silent PC with a PC to produce a noticeable noise. Furthermore, under certain circumstances, as in computers dedicated to multimedia playback, multimedia production, etc., It is essential that we hear the background noise of the computer mixed with the sound we're playing. Focusing
already on your computer, the main sources of noise are mechanical components with parts ( hard drives, fans , optical drives, etc.), And certain electronic components without mechanical moving parts (as you can see detailed this article.)
For this reason, if we want to build a silent PC, or try to silence one we already have, we focus on those elements and find solutions. The most common general solutions we use are:
Reduce consumption of components:
This reduces the need for fans or provides that we have fans running at lower speeds and therefore quieter. This reduction in consumption we can look for when choosing components for your PC, for example by looking at consumption different graphics cards, looking at different reviews the use of microprocessors, choosing power sources more efficiently (use less , etc.). We can also reduce consumption through techniques that lower the voltage or frequency of operation of the electronic components (for example, as seen in this guide voltage and frequency settings microprocessor).
Choose a well-designed box:
get much Help a silent PC choosing a properly designed box, with sufficient ventilation openings (and the right size for quiet fans), design of spaces for well-optimized components, panels do not vibrate easily, etc..
A good case should always be the starting point for any computer you want to ride with the goal of being silent, as it can largely determine the ultimate success. Choose
components suitable cooling elements: Choosing
copper or aluminum heat sinks with larger areas of dissipation, with the help of heat pipes or other technologies may be getting more efficient heat transfer component, and this may allow a lower required air flow for proper cooling. This obviously means less fan noise for the lower speed.
Such elements can be used in the most critical components in consumption and heat generation of the computer: the microprocessor, graphics chip graphics card, motherboard chipset, voltage regulators, reports, etc.
adequate and regular fans Choose your speed:
fans are needed to create an air flow to allow cooling of different items in the box, because normally by natural convection alone is not enough or is not recommended. These fans generate noise in multiple ways: engine noise, friction of mechanical parts, and even the noise of air friction (which may be higher or lower depending on the turbulence generated by the fan).
The first two forms of noise can be avoided only by choosing a proper fan, that is, a quiet fan of quality. The last air friction, is difficult to solve, but what can be done to reduce this noise by lowering the fan speed (thus reducing the air flow) through different techniques (voltage control, PWM, both hardware and software programs such as speedfan ).
Therefore, we choose quiet fans, and to regulate the minimum speed necessary to keep the computer well cooled. I mentioned in previous sections on low power components, computer box in the fridge and adequate dissipation elements, help greatly to make this possible.
Article Fans: Basic Concepts can find more details on the operation of computer fans.
Reduce noise of hard drives:
Hard drives are an item that, by its mechanical nature, generate noise on the computer. Discs are noisier and quieter, so the first intention should always be looking for a quiet drive. Additionally, you can soundproof with commercial solutions, or by other solutions like this using aluminum boxes coolpacks soundproofing. Even
can reduce noise in disk reads and writes using the feature AAM (Automatic Acoustic Management) providing some hard disks.
is also the option to choose an SSD (State Disk solid) that has no mechanical parts, but today are expensive and have no storage capacity provided by hard disks. But I'm sure that in the future will be a very good choice for fans SilentPC.
This short introduction to the concepts on silent PC will serve as an aid to better understand the ideas to be developed in future articles.
still remains to speak of many individual components of the computer, such as power supplies (which we will want to be as efficient as possible and have fan thermoregulated) motherboards and chipsets, graphics, etc. All these elements go into articles that will cover adding to this site.
These articles will be added recommendations on various components of a computer (Computer Cases, CPU and GPU heatsinks, fans, power supplies, etc.) So as to obtain a silent PC. Ye shall find when they are finished in different sections devoted to articles on this website.
In the next articles will show as an example of my three PCs silent PCs today, dedicated to different purposes:
silent PC - Example 1: Download server, with optional performance and moderate gaming PC
silent - Example 2: HTPC dedicated to multimedia playback
silent PC - Example 3: Computer Performance and games for
discs quietest formats currently available on 3.5 "disks are Western Caviar Green and Samsung EcoGreen, both 5400rpm. The reason is that spin more slowly produce less noise, although with a slight loss of performance. 
