Sound and space

The relationship between sound and space 1. Each sound space has its own different sound characteristics. Each sound space is like everyone, and it will have different sound characteristics. People will have different sounds due to the structure of the vocal cords and the different resonances of the abdominal cavity. In the same way, each sound space will have its own unique sound characteristics due to different space size, proportion and interior decoration. In other words, the voices of two people sound the same: in the same way, there are very few sounds in two acoustic spaces that sound the same.
Based on the above findings, audio fans can clearly know that even if the same audio equipment is used, different sound characteristics will occur as long as the sound space is different. These different sound characteristics are like different concert halls. As long as they are successful concert halls, they will have their own charming sound charm. The same, as long as it is a successful sound space, it will have its own charming sound charm. Often, a successful sound space is like a successful concert hall, and it is impossible to meet. You have to go through a detailed plan to build a concert hall or sound space, but this does not guarantee that you will get fascinating sound characteristics.
Second, rational audio fans should minimize their exclusivity. Every audio fan will inevitably have a habit and preference for listening to their own acoustic space because they are in their own audio space for a long time. At the same time, it is natural to judge the sound space of others and the listening habits and preferences of others based on their own listening habits and preferences. When you use your own " sound space sound characteristics", "listening habits" and "preference" as the standard to make negative judgments on others, don't forget, others can also use this foothold to make negative judgments on you. . Therefore, when you hear the sound performance different from your own, the first thing to do is not the exclusive argument, but the reflection. With reflection, trying to discover the beauty of the others sound effects.
Third, the sound effects sound space should be based on live music as the standard, and this standard is not the only sound in the end the quality of the sound effects in space there is no recognized standard? If not, isn’t there a lot of different opinions? Of course, there is a sound effect is good or bad standard, but please note that this is not the only criterion of good or bad, but multiple. Sound good and bad effects of the standard where? It is the performance of live music. Any canned fruit juice that tastes like the original fruit must be judged on the basis of fresh fruit flavor. Similarly, any good music software playback sound effect is not good, it must be based on the performance of live music as the standard to judge.
However, the beauty of the sound effects of live music is not the only, but multiple. In terms of classical music, there are a number of recognized outstanding concert hall acoustics in the world, they have different sound characteristics. Some are warm, some are full, some are clear and transparent, some are rich in low frequency, some have high intimacy (sounding is very good, the instrument seems to be very close to you). In any case, the sound characteristics of these concert halls are different.
In the home of the audio fans, the sound effects of the "unknown recording site sound characteristics", "recording equipment sound characteristics", "playback audio equipment sound characteristics", and "sound characteristics of the sound space" make the sound fans simply not qualified to discuss someone's sound effect is "true." The fans can focus on the sound, it is to discuss someone's sound effect is "beauty." The standard of "beauty" is based on the performance of live music, and it is a multiple beauty and multiple standards.
Fourth, soft-tuning space is better than hard-tuning space. What is soft-tuning space? Floors, ceilings, and four walls belonging to the splint or gypsum board or wood nails are soft-tuned spaces. What is hard-tuning space? The ceiling, the floor and the walls are all made of reinforced concrete or brick, which is called hard-adjusted space. Most of Taiwan's living environment is hard-tuned; most of the living spaces in Europe, America and Japan are soft-tuned. Why is soft-tuning space better than hard-tuning space? Because the hard-adjusted space can't absorb too many high-frequency bands and low-medium frequency bands in an appropriate amount, it causes the high frequency band to be too harsh or too low pressure in the middle and low frequency bands when listening to music. Is there any shortcoming in soft-tuning space? Do not! Soft-tuning space may also have the disadvantage of excessive absorption in the low frequency band, resulting in insufficient low frequency. However, compared to the two, soft-tuning space is more suitable for listening to music.
V. How to transform the hard-adjusted space into a soft-tuned space. Taiwan's general homes are all built with reinforced concrete or through the sky. If you want to transform the hard-adjusted space into a soft-tuned space, you can first start with four walls. On these four walls, the carpenter can use a plasterboard to nail a sandwich and a fiberglass cotton in the interlayer. This approach does not consume too much mezzanine space, but also a layer of sound insulation.
Gypsum board is better than wooden board. Perhaps you will ask, why not use a general wooden core board or a thin splint to nail the interlayer, but use a plasterboard or splint? Because thin splints or wooden cores are easy to absorb the mid-range, and the full mid-range is very important when listening to music, we can avoid thin splints or wooden cores. Because of the heavier quality of gypsum board, the absorption of the medium and low frequency is more, and the negative impact on listening to music is relatively small. Furthermore, the gypsum board is a fireproof material, and it is safer to use it for sandwiching at home. Here, I provide several sound absorption rates for gypsum board and splint for your reference: the same is 9mm plate thickness, the air layer is about 45mm thick, the gypsum board has a sound absorption rate of 0.26 at 125Hz, which can absorb some medium and low frequency stations. wave. The sound absorption rate of the splint is only 0.11. At 250 Hz, the sound absorption rate of the gypsum board is reduced to only 0.13. The sound absorption rate is lower at 500 Hz, only 0.08. Conversely, at 250 Hz, the sound absorption rate is as high as 0.23. If the thickness of the splint is reduced to 6 mm, its sound absorption rate at 250 Hz is as high as 0.33. From the above sound absorption rate, you should understand why I would recommend plasterboard.
As for the ceiling and floor, they are different from the four walls. Let me talk about the floor first. Due to the humid climate in Taiwan, the use of carpets is not appropriate. Otherwise, thick carpeting on the floor is one of the ways to soften the space. Usually, the floor of a home is usually tiled or nailed with a solid wood floor. You can put a thick wool carpet on the floor. The size of the carpet is preferably about the same size as the space from the horn to the listening position. The role of this carpet is to absorb some sound waves that are emitted from the horn to the floor and from the ceiling to the floor. Usually, this carpet will only be effective for frequencies above the intermediate frequency, and it has no absorption effect for low and medium frequencies. However, because it absorbs frequencies above the intermediate frequency, it also changes the human ear's sense of hearing at frequencies below the mid-frequency, so it sounds like the whole will change.
The mineral fiber board is cheap and easy to use. When it comes to the ceiling, the cheapest way is to use a light steel frame and a mineral fiber board. Its role is mainly in the absorption of medium and high frequency bands in the appropriate amount, and has little effect on the frequency bands below the intermediate frequency. If you think that the mineral fiber board is not good enough, you can also ask the woodworker to use the thin splint to make the ceiling shape. Please pay attention to avoid the concave shape, and make more convex shapes or curved shapes. Because the concave shape will make the sound gather somewhere, and the convex or curved shape can spread the sound wave. It is also worth noting that the shape of these ceilings is best not to be connected together in a single piece. This method will reduce the frequency range of absorption and affect the fullness of the mid-range. The correct approach should be to divide the ceiling into several zones and design the shape with the principle that each zone is not connected.
Sixth, after hard-adjusting and soft-tuning, how to deal with the surface of the space, after changing the sound space from hard to soft, then follow the principle of "Liu's good song", with the method of "pre-hardening and then diffusing" To do the surface treatment.
The back wall of the horn is hard. The so-called "pre-hard" refers to the front section of the room (that is, the section between the back wall of the horn and the horn). It is best not to do too much absorption, because this method will absorb the sound energy emitted by the horn, making it expand. The machine must have a larger output power and we will feel that the sound is strong enough. If the wall is hard, we only need a smaller amplifier, and then combine it into a strong enough sound by the reflection of the back wall.
There will be a question here? The front is not to say that the four walls are to be nailed to the softboard space? Isn't this contradicting the "pre-hard" that is required now? Whether the contradiction should be judged according to the actual situation, if the back wall of the horn is just a floor-to-ceiling window, of course, the plasterboard cannot be nailed. If the back wall of the horn is a half window, the plasterboard can be nailed or nailed (avoid the window to nail, do not seal the window, this will hinder the light and the air.) The above two situations can also make the back wall Keep it in a hard-toned state.
The more important thing to consider is that when the back wall of the horn is originally a wall, do you want to nail the plasterboard? If the power of your amplifier is not large, the speaker is not too big. I suggest that this wall should not be plastered. On the contrary, it can be nailed together.
Turn back. If you are listening to music and have already done sound absorption on the two side walls, you still feel that the sound is too sharp and too forward. At this time, you must hang a thicker material with high frequency absorption on the back wall of the speaker. This method will only absorb frequencies above the medium and high frequency bands, and will not have a negative impact on the mid-range. Therefore, it does not violate the principle of “before hard”.
The side walls are to be absorbed. The so-called "middle suction" is to perform sound absorbing surface treatment on the two side walls between the horn and the listening position. Why is this two side walls to absorb sound? Because this area is the source of the first reflected sound after the speaker makes a sound. If the first reflected sound is too strong, it will interfere with the direct sound and affect the clarity of the positioning. In addition, because the first reflection sound is too much, it will also cause pressure on the human ear above the middle and high frequency. The most direct feeling is that the sound is too bright and too harsh.
It is a mistake to have many acoustic fans in this section of the two side walls with wooden or Polyron's secondary residual diffuser. Because the diffuser plates of wood or bolsters do not contribute to the absorption of the first reflection, they only have a diffusing effect. If a secondary residual diffuser is to be used, a soft diffuser wrapped with a thick surface should be used, which has an absorption effect on the mid-high frequency band in addition to the diffusion effect. There are many ways to "suck", and the individual is ingeniously different. The Gaoming people can combine the interior decoration to create a sense of beauty. If ordinary people want to do simple things, they can also hang some soft materials, which can also meet the requirements of “sucking”. I would like to remind readers that the general curtain fabrics do not play a big role in absorption, because they are too thin, and most of them are not high-fiber soft materials, you just spend money. If you want to hang sound-absorbing materials on the two side walls, at least the material like terry cloth is effective.
As far as I know, the cheapest and effective material is fiberglass cotton. For example, a glass fiber cotton having a thickness of 5 cm and a weight of 20 kg per cubic meter has a sound absorption rate of 0.85 at frequencies above 500 Hz. You can frame the fiberglass cotton and wrap it up (do not expose it) as an image frame. This is the first reflection of the sound absorber of the two side walls. Listen to the back of the position to spread. What is "post-diffusion"? The so-called post-diffusion is to spread from the listening position to the area of ​​the back wall. In recent years, everyone knows that the secondary residual diffuser is a good diffusion tool. However, it is not known that the number of diffusers used will be sufficient. A common situation is that only a diffuser plate is placed there. This practice only produces psychological self-comforting effects and does not achieve sufficient diffusion effect. The more correct approach is to have two diffuser plates in the two corners of the back wall, and a diffuser plate in the center of the back wall, so that a total of five can add up to achieve true diffusion.
Perhaps you will ask, where is the benefit of proliferation? If the sound waves are evenly diffused, theoretically the sound reflections you hear across the listening area are average, and your listening position is not limited to one “emperor position”. Moreover, after the sound waves are evenly diffused in the acoustic space, the sound quality, the timbre, the sense of layering, the sense of depth, and the like, the performance of the " sound twenty" is enhanced.
Here to remind the reader of two things: First, not only the quadratic residue diffuser has the effect of diffusing sound waves, any bevel, convex or arc will have the effect of diffusing sound waves. However, the frequency range in which the quadratic remainder is diffused is relatively wide. So, in your sound space, you can match a variety of shapes to achieve the requirements of diffuse sound waves. Second, if you do all kinds of processing, you still feel that the sound is too sharp. At this time, I am afraid that the area behind the listening position will be sound-absorbing. At this point, your sound space will form a "front end live, back end dead" situation, so that the sound will be strong and noisy.
Seventh, reflection, absorption and diffusion must skillfully use the principle of “pre-hard-absorption and post-diffusion” discussed above. In fact, it is the three major principles of surface treatment: “reflection”, “absorption” and “diffusion” in acoustic space. These three tools must be used flexibly and try to use your imagination under the broad principles. Here I would like to remind you that when you want to imitate the treatment of others, you must first carefully evaluate whether the sound characteristics, conditions and the likes of your own audio space are the same as others. Otherwise, the result of random imitation will usually end in failure. For example, if you have followed the above principles, you still feel that the high frequency band is too bright and too harsh. At this time, you can learn Liu Renyang, a consultant of this magazine, and apply a large amount of green cloth in the room to absorb the high frequency band. On the other hand, if you already feel that the sound is a bit boring and not bright enough, then if you put a large amount of cloth on it at this time, it will be counterproductive.
Remember, we carefully modulate the reflection, absorption, and diffusion of sound waves in order to get the sounds of "warm," "full," "soft," "rich," "clear," and "transparent." If you hear sharp, harsh, thin, white hot sounds, listening to music will be a painful trial, not a relaxing experience.
Eight, the quadratic residue diffuser is very easy to use before the second remainder, let's talk about diffusion. The so-called diffusion is that the sound waves emitted by the horns are reflected into the reflector from that direction, and the sound waves are evenly reflected in all directions. Therefore, diffusion can be said to be non-directional. What about general sound wave reflection? Usually oriented. For example, a slope is used to reflect sound waves. Theoretically, as long as the length of a reflecting surface is greater than the wavelength of the acoustic wave, all frequencies having a smaller wavelength than the reflecting surface will be reflected in a certain direction.
From the above description, you can understand that in the acoustic space of the audio fan, what we need is diffusion, not directional reflection. Because the diffusion will make the sound waves in the room more uniform, and the directional reflection will only affect a certain part. Then, what is the second remainder? Its English is Quadratic Residue. This name comes from the calculation formula hn = (λ0/2N)?Sn, where Sn is the remainder of n square divided by N. Where λ0 is the center frequency wavelength at which diffusion is desired (for example, center frequency at 1000 Hz), and N is the number of diffuser grids (ie, step) that you determine. Please note that the number of steps must be prime, such as 7, 11, 13, 19, 23, 29... and so on. n is 0,1,2,3,4,5,6,7,... Hn is the height of n step. The benefit is that the spread is very wide. In fact, telling readers that the simple formula of the second remainder diffusion may not help you understand the spread of sound waves. My main purpose is to let you know the origin of the noun. There are many types of diffusers based on this theory, including diffusion for specific use, diffusion and absorption, and diffusion, absorption and reflection. In addition, in addition to the use of the wall, there are also ceilings.
Why is the secondary remainder diffuser popular in recent years? Because it has a diffusion characteristic: if the center frequency is used, the lower limit of its diffusion range can extend down to about half the frequency below the center frequency (if the center frequency is 1000 Hz, the half frequency is 750 Hz), the upper limit is very high. , can reach (N-1) times the center frequency. Assuming that the center frequency is 1000 Hz and the step of the quadratic residue diffuser is 7, the upper limit of the diffusion range is about 6000 Hz.
Seeing here, I think you already know that the quadratic residue diffusers that are generally seen outside are almost all frequencies above the intermediate frequency; and the more the number of steps (the number of steps here is a single group, not two) The sum of the three groups of groups), the upper limit of the diffusion frequency is higher. In addition, why no one will do three or five steps? Because its upper limit of diffusion is relatively low.
Nine, big space is better than small space. Why is a large space better than a small space? The reason is very simple, because the volume of the large space is large, the sound waves emitted by the horn are less distorted by the boundary (six-sided wall), and the sound you get will be more correct. That's why if we use computer software for horn testing, we usually have to ask for measurements in larger spaces. Because the sound waves have less distortion of the boundary, the test results will be more accurate. Many people don't know. In fact, the effective value of many speaker computer test software is only above 300Hz. The frequency below 300Hz is easy to be interfered by the inner boundary of the space because of the long wavelength, which makes the test value unreliable. The goal of the non-sounding room is to completely eliminate the interference of the space boundary in theory, so that the test results are accurate and credible.
In the average person's home, the large space is the open space shared by the living room and the restaurant. The small space is a specially designed sound room or general room. In the large space, what we need to consider is the multi-functional sharing of space, the interference during listening, and whether the low-frequency sense of the speaker is sufficient. If you can properly deploy, the sound you get will usually be easier, more uniform and correct, and the ability to snorkel down will be stronger. As for standing waves, even large spaces cannot be completely avoided, but the degree of harm will be relatively reduced.
In a small space, the sound waves emitted by the horn are severely distorted by the boundary, and the damage of the standing wave is far greater than that in the large space, and the extension of the low frequency band is always limited. However, due to the small size of the small space, it is not necessary to use a high-power amplifier and a large speaker, and the space arrangement is relatively trouble-free.
Ten, things are much better than things. This does not mean that the more equipment, the better, but the more things in the sound space, the better. However, the more things you have, the more you have to organize them. Don't just throw them away, causing the whole room to be messy. Why is the more things in the sound space the better? Because these things will naturally absorb and reflect the sound waves, and achieve the effect of naturally regulating the indoor reverberation. Keep in mind that the heavier the quality, the more it absorbs the mid-low or low-frequency, and sometimes solves some of the low-frequency standing waves. For example, cabinets, sofas, bookshelves, CD stands, etc. all have this function. The multi-fiber, porous and soft surface has an absorption effect on high frequencies, such as the surface of a flannel sofa, a velvet carpet, and the like.
If there are few things in the sound space, there is only one set of sound and a few CDs and a sofa. The space of such a spring is easy to produce shortcomings such as long echo, high frequency, and false sound. Similarly, if all kinds of cabinets in the sound space are equipped with glass doors, too many high-frequency reflections will occur. Therefore, it is best not to have glass doors for all kinds of cabinets in the sound space.
XI, the proportion of the sound space is important? The proportion of the so-called audio space, the average person will get used to the so-called "golden ratio." In fact, the word "gold" here only represents precious and rare, and has nothing to do with the real "golden ratio". Why should the sound space pay attention to the ratio of length to width? If the ratio is correct and correct, the standing wave intensity in the acoustic space can be minimized, and the interference of the medium and low frequency standing waves to the listening music can be reduced. Therefore, if you have the opportunity to decorate an undisturbed dedicated sound room, of course, you should pay attention to the length, width and height of the space. The innate conditions are first available, and the adjustment of the day after tomorrow, the effect of the sound space will of course be superior.
What is the ratio of the best golden ratio? If you want to be simple, as long as the values ​​of length, width and height do not double each other. To put it bluntly, these three values ​​cannot be removed from each other. If you pay attention to it, you have to carry some simple numbers, which are all related numbers that are calculated by computer and have low standing wave strength. You can remember the following three groups: A. 1.00: 1.14: 1.39; B. 1.00: 1.28: 1.54; C. 1.00: 1.60: 2.33. The 1.00 of the above three sets of numbers represent the height of the room, and the other two are width and length respectively. From a numerical point of view, you can see that this is a ratio of the space of three different sizes. In the end, you should use that ratio, depending on how much space you have.
Twelve, the standing wave should only be taken by wisdom, and what is the purpose of not doing the standing wave? Simply put, standing waves are sound waves that do not go away. Lai, don't you go there? Lay between two opposing parallel walls. There are three sets of opposing parallel walls in one space, so there will be three sets of standing waves mixed together in one sound space.
In fact, the standing wave is the resonance phenomenon of space. As long as the distance between two opposing parallel walls is equal to an integral multiple of half wavelength, resonance will occur, that is, standing wave. For example, a distance of 5 meters is half the wavelength of 34Hz (the speed of sound is 340 meters per second divided by the frequency of 34Hz is 10 meters of full wavelength), such a length will be 2, 3, 4 at 34Hz, Standing waves are generated at 5, 6, ... times. That is, standing waves are generated at 34 Hz, 68 Hz, 102 Hz, 136 Hz, and the like.
If the standing waves generated by the three parallel walls in the space overlap each other, a stronger standing wave will be formed. This stronger overlapping standing wave is the standing wave commonly known by our audio fans. For example, if three parallel walls have exactly 102 Hz standing waves, then the strongest standing wave in this acoustic space is 102 Hz.
In fact, standing waves in the acoustic space will not only occur on parallel walls, but also on the length of the diagonal. Therefore, when the horn is playing music, the standing waves generated in the acoustic space are very complicated. Fortunately, audio fans don't need to understand the complex standing waves, you only need to know the cause of the standing wave formation.
Why do I say that the standing wave should only be taken by wisdom, not to do it? First, standing waves are not just a single frequency. They are so wide that you can't accurately “offset” them with some kind of facility. Second, the standing wave energy is very strong, usually more than ten dB higher than the sound pressure of normal music. Such a strong sound pressure is not at all compatible with the tuning skills used to "fine-tune". Therefore, based on my many years of experience, the best way for audio fans to deal with standing waves is to avoid it. What method to avoid? Avoid using the horn to position and change the listening position.
If I have to use some measure to reduce a strong standing wave, can it be successful? If you want to do it at no cost, of course there are many methods developed by the predecessors. For example, if you want to absorb 102Hz, you should use the formula to calculate, what kind of sound-absorbing material, how to install it, and how much to absorb it. In the studio, there are many such facilities that absorb low and low frequencies. Alternatively, you can design a large quadratic residue diffuser that specifically spreads the lower frequency bands. However, it is still an old saying that the amount absorbed is not only impossible to control accurately, but also has a negative impact on adjacent frequency bands.
Here I want to emphasize again: the most effective way to deal with standing waves is to build a sound space of the right proportion. If there is no chance to build, the most trouble-free and clever way is to avoid it by "trumpet placement" and "changing the listening position." Many people are very "iron teeth", but they don't believe in evil. They want to confront the standing waves. To be honest, I have already passed the "iron teeth". My experience is the old man's words. If you don't listen to the old saying, you will lose money in front of you.
Thirteen, the sound space should consider the reverberation time problem? What is the reverberation? "Reverberation" in English is Reverberation, and Chinese also has reverberation or reverberation. On the surface, the reverberation seems to be the same thing as the echo and the hall sound, but it is not. Echo means that when a sound is emitted, we can hear another identical sound later, just as the sound comes out and comes back, so it is called echo. Ambience refers to the enveloping atmosphere of music in a concert hall, which consists of the first reflected sound after the sound is emitted and the reflected sound later. By the time when the first reflection is transmitted back to the ear, we can roughly judge the size of the space. The reverberation has a strict definition of reverberation, which, as the name suggests, is of course a response that remains in space after the sound is emitted. However, it also comes with a strict rule: when a sound source emits a sound, the sound intensity is reduced to the time when only the initial negative 60dB intensity, we call it the reverberation time. Note that no, the key figure is "negative 60dB intensity." This is what the average person calls RT-60.
What is the importance of reverberation time for listening to music? Although it does not represent everything that sounds perform, it has a great influence on the "quality" of sound. For example, the sound sounds warm or not, full or not, clear or not; or brighter, more gorgeous, and so on. In the modern concert hall design, the reverberation time is usually set at about 2 seconds.
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the relationship between sound and space, each Each sound space has its own different sound characteristics. Each sound space is like everyone, and it has different sound characteristics. People will have different sounds due to the structure of the vocal cords and the different resonances of the abdominal cavity. In the same way, each sound space will have its own unique sound characteristics due to different space size, proportion and interior decoration. In other words, the voices of two people sound the same: in the same way, there are very few sounds in two acoustic spaces that sound the same.
Based on the above findings, audio fans can clearly know that even if the same audio equipment is used, different sound characteristics will occur as long as the sound space is different. These different sound characteristics are like different concert halls. As long as they are successful concert halls, they will have their own charming sound charm. The same, as long as it is a successful sound space, it will have its own charming sound charm. Often, a successful sound space is like a successful concert hall, and it is impossible to meet. You have to go through a detailed plan to build a concert hall or sound space, but this does not guarantee that you will get fascinating sound characteristics.
Second, rational audio fans should minimize their exclusivity. Every audio fan will inevitably have a habit and preference for listening to their own acoustic space because they are in their own audio space for a long time. At the same time, it is natural to judge the sound space of others and the listening habits and preferences of others based on their own listening habits and preferences. When you use your own " sound space sound characteristics", "listening habits" and "preference" as the standard to make negative judgments on others, don't forget, others can also use this foothold to make negative judgments on you. . Therefore, when you hear the sound performance different from your own, the first thing to do is not the exclusive argument, but the reflection. With reflection, trying to discover the beauty of the others sound effects.
Third, the sound effects sound space should be based on live music as the standard, and this standard is not the only sound in the end the quality of the sound effects in space there is no recognized standard? If not, isn’t there a lot of different opinions? Of course, there is a sound effect is good or bad standard, but please note that this is not the only criterion of good or bad, but multiple. Sound good and bad effects of the standard where? It is the performance of live music. Any canned fruit juice that tastes like the original fruit must be judged on the basis of fresh fruit flavor. Similarly, any good music software playback sound effect is not good, it must be based on the performance of live music as the standard to judge.
However, the beauty of the sound effects of live music is not the only, but multiple. In terms of classical music, there are a number of recognized outstanding concert hall acoustics in the world, they have different sound characteristics. Some are warm, some are full, some are clear and transparent, some are rich in low frequency, some have high intimacy (sounding is very good, the instrument seems to be very close to you). In any case, the sound characteristics of these concert halls are different.
In the home of the audio fans, the sound effects of the "unknown recording site sound characteristics", "recording equipment sound characteristics", "playback audio equipment sound characteristics", and "sound characteristics of the sound space" make the sound fans simply not qualified to discuss someone's sound effect is "true." The fans can focus on the sound, it is to discuss someone's sound effect is "beauty." The standard of "beauty" is based on the performance of live music, and it is a multiple beauty and multiple standards.
Fourth, soft-tuning space is better than hard-tuning space. What is soft-tuning space? Floors, ceilings, and four walls belonging to the splint or gypsum board or wood nails are soft-tuned spaces. What is hard-tuning space? The ceiling, the floor and the walls are all made of reinforced concrete or brick, which is called hard-adjusted space. Most of Taiwan's living environment is hard-tuned; most of the living spaces in Europe, America and Japan are soft-tuned. Why is soft-tuning space better than hard-tuning space? Because the hard-adjusted space can't absorb too many high-frequency bands and low-medium frequency bands in an appropriate amount, it causes the high frequency band to be too harsh or too low pressure in the middle and low frequency bands when listening to music. Is there any shortcoming in soft-tuning space? Do not! Soft-tuning space may also have the disadvantage of excessive absorption in the low frequency band, resulting in insufficient low frequency. However, compared to the two, soft-tuning space is more suitable for listening to music.
V. How to transform the hard-adjusted space into a soft-tuned space. Taiwan's general homes are all built with reinforced concrete or through the sky. If you want to transform the hard-adjusted space into a soft-tuned space, you can first start with four walls. On these four walls, the carpenter can use a plasterboard to nail a sandwich and a fiberglass cotton in the interlayer. This approach does not consume too much mezzanine space, but also a layer of sound insulation.
Gypsum board is better than wooden board. Perhaps you will ask, why not use a general wooden core board or a thin splint to nail the interlayer, but use a plasterboard or splint? Because thin splints or wooden cores are easy to absorb the mid-range, and the full mid-range is very important when listening to music, we can avoid thin splints or wooden cores. Because of the heavier quality of gypsum board, the absorption of the medium and low frequency is more, and the negative impact on listening to music is relatively small. Furthermore, the gypsum board is a fireproof material, and it is safer to use it for sandwiching at home. Here, I provide several sound absorption rates for gypsum board and splint for your reference: the same is 9mm plate thickness, the air layer is about 45mm thick, the gypsum board has a sound absorption rate of 0.26 at 125Hz, which can absorb some medium and low frequency stations. wave. The sound absorption rate of the splint is only 0.11. At 250 Hz, the sound absorption rate of the gypsum board is reduced to only 0.13. The sound absorption rate is lower at 500 Hz, only 0.08. Conversely, at 250 Hz, the sound absorption rate is as high as 0.23. If the thickness of the splint is reduced to 6 mm, its sound absorption rate at 250 Hz is as high as 0.33. From the above sound absorption rate, you should understand why I would recommend plasterboard.
As for the ceiling and floor, they are different from the four walls. Let me talk about the floor first. Due to the humid climate in Taiwan, the use of carpets is not appropriate. Otherwise, thick carpeting on the floor is one of the ways to soften the space. Usually, the floor of a home is usually tiled or nailed with a solid wood floor. You can put a thick wool carpet on the floor. The size of the carpet is preferably about the same size as the space from the horn to the listening position. The role of this carpet is to absorb some sound waves that are emitted from the horn to the floor and from the ceiling to the floor. Usually, this carpet will only be effective for frequencies above the intermediate frequency, and it has no absorption effect for low and medium frequencies. However, because it absorbs frequencies above the intermediate frequency, it also changes the human ear's sense of hearing at frequencies below the mid-frequency, so it sounds like the whole will change.
The mineral fiber board is cheap and easy to use. When it comes to the ceiling, the cheapest way is to use a light steel frame and a mineral fiber board. Its role is mainly in the absorption of medium and high frequency bands in the appropriate amount, and has little effect on the frequency bands below the intermediate frequency.假若您嫌矿纤板不够好看,也可以请木工用薄夹板做天花板造型。请注意要避免凹型的造型,多做凸出的造型或弧形。因为凹型会使声音聚在某处,而凸型或弧形可以扩散声波。还有一点要注意的,这些天花板上的造型最好不要一整片连在一起,这种作法会使其吸收的频率范围降低,影响了中频段的饱满。正确的作法应该是将天花板分割成几个区,以每区互不相连的原则来设计造型。
六、硬调变软调之后,空间的表面要如何处理将音响空间由硬调转为软调之后,接着可以按照“刘氏好声歌”的原则,以“前硬中吸后扩散”的方法来做表面处理。
喇叭后墙要硬。所谓“前硬”指的是房间的前段(也就是喇叭后墙与喇叭之间那段)最好尽量不要做太多吸收的装置,因为这样的作法会吸收喇叭所发出的声能,使得扩大机必须有更大的输出功率我们才会觉得声音够结实。如果这段墙面是硬的,我们只需要较小的扩大机,再藉由后墙的反射,结合成足够结实的声音。
在此会有一个疑问?前面不是说四壁要钉石膏板变成软调空间吗?这样岂不是与现在所要求的“前硬”相互矛盾?是否矛盾要依实际情况来判断,假若喇叭后墙刚好是落地窗,当然不能钉石膏板。假若喇叭后墙是半窗,石膏板可以不钉,也可以钉(避开窗户来钉,千万不要将窗户封死,这样有碍光线与空气。)以上二种情形都还能令后墙保持在硬调的状态。
比较需要考虑的是喇叭后墙本来就是一面墙时,到底要不要钉石膏板?如果您的扩大机功率不算大,喇叭也不算大,我建议这面墙不要钉石膏板。反之,就可以一并钉起来。
话说回头。如果您在听音乐时,已经在二侧墙做吸音处理之后,还是觉得声音太尖锐太前冲,此时就必须在喇叭后墙挂一块比较厚、具有吸收高频特性的材料。这样的作法只会吸收中高频段以上的频率,对于中频段以下不会有负面影响。因此它并不违背“前硬”的原则。
侧墙要吸收。所谓“中吸”,就是在喇叭与聆听位置之间的二侧墙做吸音表面处理。为什么这一段二侧壁要吸音呢?因为这个区域是喇叭发出声音后,第一次反射音的来源。而第一次反射音如果过强过多,会对直接音造成干扰,影响定位感的清晰。此外,因为第一次反射音过多,也会造成中高频以上对人耳的压力,最直接的感受就是声音太亮太刺耳。
常见许多音响迷在这一段二侧墙摆了木质或保利龙的二次余数扩散板,这是错误的作法。因为木质或保力龙的扩散板无助于第一次反射音的吸收,它们只有扩散的作用。如果要用二次余数扩散板,则应该使用表面厚布包起来的软质扩散板,它除了扩散作用之外,还对中高频段具有吸收作用。 有关“中吸”的作法很多,个人巧妙不同。高明者可以结合室内装潢,产生令一种美感。一般人如果想要简单行事,也可以吊挂一些软质材料,同样可以达到“中吸”的要求。在此要提醒读者们,一般的窗帘布对吸收起不了什么大作用,因为它们太薄了,而且多数并非高纤软质材料,您只是白花钱而已。如果您想在二侧壁挂吸音材料,至少都要像厚绒布那样的材料才有效。
就我所知,最便宜而有效的材料就是玻璃纤维棉。以厚度为5cm,每立方公尺重量为20公斤的玻璃纤维棉为例,它在500Hz以上的频率都有高达0.85的吸音率。您可以将玻璃纤维棉框起来,包起来(千万不要裸露),作成像画框一般。这就是效果相当好的二侧墙第一次反射音吸收体。聆听位置后面要扩散。什么是“后扩散”呢?所谓后扩散就是从聆听位置开始到后墙的这个区域来做扩散。近年,大家都知道二次余数扩散板是很好的扩散工具,不过,并不知道使用扩散板的数量要够多才会有效。常见的情形是只摆了一个扩散板在那里,这种作法只会产生心理的自我安慰效果,并无法做到足够的扩散效果。比较正确的作法应该是后墙的二个墙角各摆二个扩散板,后墙的中央再摆一个扩散板,这样加起来总共五个才能发挥真正的扩散功效。
或许您会问,到底扩散的好处在那里呢?如果声波能够得到均匀的扩散,理论上您在聆听区域各处所听到的声波反射都很平均,您的聆听位置就不会只局限于一个“皇帝位”。再者,声波在音响空间内得到均匀扩散之后,明显的会提升音质、音色以及层次感、深度感等“ 音响二十要”的表现。
在此要提醒读者二件事:第一、并不是只有二次余数扩散器材有扩散声波的效果,任何的斜面、凸面或圆弧都会有扩散声波的效果。只不过二次余数所扩散的频率范围比较宽而已。所以,在您的音响空间中,您大可搭配各种的造型以达到扩散声波的要求。第二、如果您做了各种处理,仍然觉得声音太尖锐,此时,聆听位置后面这个区域恐怕就要做吸音处理了。此时,您的音响空间就会形成“前端活、后端死”的情况,这样听起来声音会结实有力而不吵杂。
七、反射、吸收与扩散三者必须巧妙运用以上所谈的“前硬中吸后扩散”原则,事实上就是音响空间中“反射”、“吸收”与“扩散”三种表面处理大原则。这三种手段必须灵活运用,并尽量在大原则的范围之下发挥您的想象力。在此我要提醒您,当您想模仿别人的处理方式时,一定要先仔细评估,自己音响空间的声音特性、各项条件以及本身好恶是否与别人相同。否则,胡乱模仿的结果通常会以失败收场。例如,如果您已经按照以上原则去处理之后,还是觉得高频段太亮太刺耳,此时可以学本刊顾问刘仁阳,在房间内施盖大量绿布,以吸收高频段。反之,假若您已经觉得声音有点闷,不够亮丽,此时如果再大量盖布一定会适得其反。
请记住,我们精心的调配反射、吸收与扩散声波,为的就是要得到“温暖”、“饱满”、“柔和”、“丰润”、“清澄”、“透明”的声音。如果您听到的是尖锐、刺耳、单薄、白热的声音,那么听音乐将成为痛苦的试炼,而非轻松愉快的享受。
八、二次余数扩散器十分好用在说二次余数之前,先说扩散。所谓扩散就是喇叭发出的声波无论从那个方向射入一个反射体,那些声波都会均匀的向各个方向反射。所以,扩散可以说是无指向的。而一般的声波反射呢?通常是定向的。例如利用一个斜面来反射声波。理论上,只要是一个反射面的长度大于声波波长,则所有波长比反射面小的频率都会被反射到某个方向。
从以上的叙述中,您可以了解,在音响迷的音响空间中,我们需要的是扩散,而不是定向的反射。因为扩散会使室内的声波更均匀,而定向反射只会对某个局部达成影响。再来,什么是二次余数呢?它的英文是Quadratic Residue。这个名称来自于计算公式hn = (λ0/2N)?Sn中,Sn就是以n平方除以N的余数而来。式中λ0是想要扩散的中心频率波长(例如以1000Hz为中心频率),N是您决定的扩散器格子数(也就是踏步)。请注意,踏步的数目必须是质数,例如7,11,13,19,23,29…等等。n则是0,1,2,3,4,5,6,7,…。hn则是n那个踏步的高度。 好处是扩散范围很宽。其实,告诉读者们二次余数扩散的简单公式,可能无助于您对于声波扩散的了解,我主要的目的是要让您了解这个名词的由来。以这种理论为基础的扩散器种类很多,其中有专门扩散用的,也有扩散与吸收二者兼用的,更有扩散、吸收与反射三者兼用的。此外,除了供墙壁使用之外,也有供天花板使用的。
为什么二次余数扩散器会在近年倍受欢迎呢?因为它有一个扩散特性:如果以中心频率为准,它扩散范围的低限可以向下延伸到中心频率以下约半倍频(假若中心频率为1000Hz,半倍频就是750Hz),上限则很高,可以达到中心频率的(N-1)倍。假设中心频率为1000Hz,该二次余数扩散器的踏步为7,则扩散范围的上限约6000Hz。
看到这里,我想您已经了解,一般外面所见到的二次余数扩散器几乎都是针对中频以上的频率;而且踏步数越多(这里指的踏步数是单组的数,而不是二组三组的总和),扩散频率的上限也就越高。此外,为什么没有人会做三个、五个踏步的?因为它扩散的上限比较低。
九、大空间比小空间好为什么大空间会比小空间好?道理很简单,因为大空间的容积较大,喇叭发出来的声波受边界(六面墙)扭曲程度比较小,您所得到的声音将会比较正确。这也是为什么如果我们使用计算机软件做喇叭测试时,通常都必须要求在越大的空间下测量。因为声波少了边界的干扰扭曲,测试结果才会越准确。很多人不知道,其实许多喇叭计算机测试软件的有效值只在300Hz以上而已,低于300Hz的频率因为波长较长,容易受空间内边界的干扰,以至于造成测试值的不可信。而无响室所要达到的目标,其实就是在理论上完全消除空间边界的干扰,使得测试结果准确可信。
在一般人的家中,大空间就是客厅与餐厅共享的开放空间,小空间就是特别设计的音响室或一般房间。在大空间中,我们所需要考虑的是空间的多功能共享、聆乐时的干扰、以及喇叭的低频量感是否足够等问题。如果能够适当调配,您所得到的声音通常都会比较轻松、均匀与正确,而且低频向下沉潜的能力会更强。至于驻波,即使大空间也不可能完全避免,不过危害的程度会相对的降低。
在小空间中,喇叭发出的声波受边界扭曲得很严重,驻波的危害也远大于大空间中,低频段的延伸也永远受限。不过,小空间由于容积小,可以不必使用大功率扩大机与大型喇叭,空间的布置也比较省事。
十、 东西多比东西少好这里不是指器材越多越好,而是音响空间里的东西越多越好。不过,东西越多越要整理,不要随便乱丢,造成满室脏乱。为什么音响空间里的东西越多越好呢?因为这些东西会对声波产生自然的吸收与反射作用,达到自然调节室内残响的作用。请记住,质量越重的东西对于中低频或低频越会产生吸收作用,有时候可以解决一些中低频驻波的问题。例如柜子、沙发、书架、CD架等都具有这种功能。而表面多纤维、多孔软质的东西则对高频具有吸收作用,例如绒布沙发的表面,地毯厚绒布等等。
假若音响空间内东西很少,只有一套音响以及几张CD、一张沙发,这么阳春的空间很容易产生回音过长,高频太亮,声音虚而不实的缺点。同样的,如果音响空间里的各种柜子都装上玻璃门,也会产生过多的高频反射。所以音响空间内的各种柜子最好都不要有玻璃门。
十一、 音响空间的比例重要吗所谓音响空间的比例,一般人都会习惯的称为“黄金比例”。事实上这里“黄金”二字只是代表珍贵难得而已,与真正的“黄金比例”无关。为什么音响空间要讲究长宽高的比例呢?如果比例正确恰当,可以将音响空间内的驻波强度降到最低,减少中低频驻波对于聆赏音乐的干扰。所以,如果您有机会装修一间不受干扰的专用音响室,当然要顺便讲究空间的长宽高比例。先天条件先具备,加上后天的布置调整, 音响空间的效果当然就会高人一等。
到底怎么样的比例才是最好的黄金比例呢?如果要简单点,只要是长宽高的数值不要互成倍数就可。说得白话些, 这三个数值相互无法除尽即可。若是讲究些,则要背一些简单的数字,这些数字都是以计算机计算过,驻波强度很低的相关数字。您可以记住以下三组:A. 1.00 : 1.14 : 1.39;B. 1.00 : 1.28 : 1.54;C. 1.00 : 1.60 : 2.33。以上三组数字的1.00代表着房间的高度,其余二个分别为宽与长。从数字上看,您可以发现这是三个容积大小不同的空间比例,到底要用那一种比例,那就看您有多大的空间而定了。
十二、 驻波只宜智取,不要蛮干驻波是什么玩意?简单的说,驻波就是赖着不走的声波。赖在那里不走呢?赖在二个对立的平行墙面之间。一个空间有三组对立的平行墙面,所以,一个音响空间就会有三组驻波混在一起。
其实,驻波就是空间的共振现象,只要二对立平行墙面的距离等于半波长的整倍数,就会产生共振,也就是驻波。、例如,一个5公尺长的距离就是34Hz的半波长(声音的速度每秒340公尺除以频率34Hz就是全波长10公尺),这样的长度就会在34Hz的2, 3, 4, 5, 6, …倍处产生驻波。也就是在34Hz, 68Hz, 102Hz,136Hz…等处产生驻波。
假若,空间内三组平行的墙面个别所产生的驻波有相互重叠之处,那就会形成更强的驻波。这个更强的重叠驻波就是我们音响迷俗称的驻波。例如,如果三个平行墙面恰好都有102Hz的驻波,那么,这个音响空间中最强烈的驻波就是102Hz。
事实上, 音响空间内的驻波不仅会发生在平行墙面上,也会发生在对角线的长度上。所以,当喇叭在播放音乐时, 音响空间内所产生的驻波是非常复杂的。幸好, 音响迷并不需要了解那么复杂的驻波,您只需要知道驻波形成的原因就可以了。
为什么我说驻波只宜智取,不要蛮干?第一,驻波并不是只有单一频率而已,它的范围很广,您无法以某种设施去准确的“抵销”它们。第二,驻波的能量很强,通常会比正常音乐的音压还高十几dB以上。这么强的音压根本不是以用来“微调”的调声秘技所能够应付的。所以,依我多年的经验, 音响迷对付驻波最好的方法就是避开它。用什么方法避开呢?用喇叭摆位以及变换聆听位置的方式来避开。
假若我硬要用某种措施来降低某个强烈的驻波,是不是可以成功?如果您想不计代价去做,当然有许多前人研究出来的方法。例如假若要吸收102Hz,就要利用公式计算,用什么吸音材料、怎么安置法,用量多少去吸收它。在录音室中,多少都会有这种吸收中低频与低频的设施。或者,您也可以设计一个很大的二次余数扩散器,专门扩散较低的频段。不过,还是那句老话,吸收的量不仅无法精确的控制,还会对邻近频段做负面的影响。
在此我要再度强调:对付驻波最有效的方式就是建造一个比例恰当的音响空间。假若没有机会建造,最省事、最聪明的方法就是以“喇叭摆位”与“变换聆听位置”来避开它。许多人很“铁齿”,偏偏不信邪,就是想要与驻波正面交锋。老实说,我已经“铁齿”过了,我的经验就是老人言。如果您不听老人言,吃亏就会在眼前。
十三、 音响空间要考虑残响时间问题吗什么是残响?“残响”英文是Reverberation,中文也有称混响或余响者。表面上看,残响好象与回音、堂音是相同的东西,实则不然。回音是指当一个声音发出后,我们可以在稍后听到另一个相同的声音,就好象声音跑出去后又回来了,所以叫回音。堂音(Ambience)指的是在音乐厅中音乐的包围气氛,它是由声音发出之后的第一次反射音以及稍后的反射音组成。藉由第一次反射音传回耳朵的时间,我们可以概略的判断该空间的大小。残响有严格的定义至于残响,顾名思义,它当然也是声音发出之后残留在空间中的响应。不过,它还附带了一个严格的规定,那就是:当一个声源发出声音之后,声音强度降低到只有最初的负60dB强度时的时间,我们就称它为为残响时间。注意到没有,关键的数字就是“负60dB的强度”。这也就是一般人所称的RT-60。
到底残响时间对于听音乐有什么重要性呢?虽然它不能代表声音表现的一切,但是它对于声音的“质”具有很大的影响力。例如声音听起来温暖与否、饱满与否、清晰与否;或者是比较明亮的、华丽的等等。在现代的音乐厅设计中,残响时间通常都订在2秒左右。
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音响与空间的关系一、 每个音响空间都有其不同的声音特性每一个音响空间就好象每一个人,都会有其不同的声音特性。人会因为声带的结构,胸腔腹腔的不同共鸣而产生不同的声音。同样的,每一个音响空间也会因为不同的空间大小、比例、室内装潢而拥有自己独特的声音特性。换句话说,很少有二个人的声音听起来是一样的:同样的,也很少会有二个音响空间的声音听起来一样。
基于以上的认知, 音响迷可以清楚的知道,即使使用完全相同的音响器材,只要是音响空间不同,就会产生不同的声音特性。这些不同的声音特性就好象不同的音乐厅,只要是成功的音乐厅,就会拥有它们各自迷人的声音魅力。相同的,只要是成功的音响空间,也都会拥有自身迷人的声音魅力。通常,成功的音响空间就好象成功的音乐厅,是可遇而不可求的。您必须经过周详的计画去建构一个音乐厅或音响空间,但是这并不保证您一定可以获得迷人的声音特性。
二、 理性的音响迷应将自身的排他性降到最低每一个音响迷,难免会因为长期处于自己的音响空间中,而产生适应自身音响空间的聆乐习惯与偏好。同时,也很自然的会以自身的聆乐习惯与偏好为基准,去评断别人的音响空间与别人的聆乐习惯、偏好。当您以自身的“ 音响空间声音特性”、“聆乐习惯”以及“偏好”为标准,去对别人做负面评断时,不要忘了,别人也同样可以利用这样的立足点对你做负面评断。因此,当您听到不同于自身的声音表现时,首先要做的并不是油然而生的排他论断,而是反思。藉由反思,尝试的去发现别人音响效果的美处。
三、 音响空间的音响效果应以现场音乐为标准,而此标准并非唯一到底音响空间中音响效果的好坏有没有一个认定标准?如果没有,岂不是众说纷纭,莫衷一是? 音响效果当然有一个好坏的标准,但是请注意,这个好坏的标准并不是唯一的,而是多重的。 音响效果好坏的标准在那里?在于现场音乐的演奏效果。任何罐头果汁喝起来像不像原来的水果,都必须以新鲜的水果风味为标准去评断。同样的,任何的音乐软件回放的音响效果好不好,也必须以现场音乐的表现为标准去评断。
然而,现场音乐的音响效果之美并不是唯一的,而是多重的。就古典音乐而言,世界上有许多公认音响效果杰出的音乐厅,它们各有不同的声音特性。有的温暖,有的饱满,有的澄澈透明,有的低频丰富,有的声音亲密性高(听起来包围感很好,乐器好象离您很近)。无论如何,这些音乐厅的声音特性各有所美。
而在音响迷的家中,由于经过“不可知的录音场地声音特性”,“录音器材声音特性”、“回放音响器材声音特性”、以及“自身音响空间的声音特性”等四重影响,使得音响迷根本没有资格去讨论谁家的音响效果为“真”。 音响迷所能够着力的,就是讨论谁家的音响效果为“美”。而这个“美”的标准就是以现场音乐的表现为准,而且是多重的美、多重的标准。
四、 软调空间比硬调空间好什么是软调空间?地板、天花板、四壁属于夹板或石膏版或木板钉成者,就是属于软调空间。什么是硬调空间?天花板、地板以及四壁都以钢筋水泥或砖砌的空间,就称硬调空间。大部份台湾的居住环境都属于硬调空间;而大部份欧美、日本的居住空间都属软调空间。为什么软调空间会比硬调空间好呢?因为硬调空间无法适量的吸收过多的高频段与中低频段,造成聆听音乐时高频段过于刺耳或中低频段过于压迫的缺点。是否软调空间就毫无缺点呢?不!软调空间可能也会存在低频段吸收过量,产生低频不够结实的缺点。不过,二者相较,软调空间还是比较适合聆听音乐。
五、要如何把硬调空间转变为软调空间台湾一般住家都是以钢筋水泥建成的公寓或透天厝,如果要将将硬调空间转化成软调空间,首先可以动手的就是四面墙壁。这四面墙壁可以请木工师父用石膏板钉一个夹层,夹层里铺玻璃纤维棉。这样的作法既不会耗去太多夹层空间,也可以多一层的隔音效果。
石膏板比木心板好。或许您会问,为什么不用一般木心板或薄夹板来钉夹层,而要用石膏板或夹板?因为薄夹板或木心板容易吸收中频段,而听音乐时中频段的饱满非常重要,所以我们可以避开用薄夹板或木心板。而石膏板由于质量较重,所吸收的中低频比较多,对于我们聆听音乐的负面影响比较小。再者,石膏板是防火材料,家里使用它来做夹层会比较安全。在此,我提供石膏板与夹板的几个吸音率以供您参考:同样是9mm板厚,空气层约45mm厚时,石膏板在125Hz时的吸音率为0.26,可以多吸收一些中低频驻波。而夹板的吸音率才0.11。而在250Hz时,石膏板的吸音率就降低了,才只有0.13。到500Hz时吸音率则更低,只有0.08而已。相反的,夹板在250Hz时,吸音率就高达0.23。假若夹板的厚度降低为6mm,它在250Hz时的吸音率更高达0.33。从以上的吸音率来看,您应该了解为什么我会建议采用石膏板。
至于天花板与地板的作法,它们与四壁的作法又有不同。先说地板。台湾由于气候潮湿,使用地毯比较不适当。否则,地板上铺厚地毯也是软化空间的方法之一。通常,一般居家的地板都是铺磁砖或再钉一层实木地板。您可以在这样的地板上铺上一块厚厚的羊毛地毯,地毯的大小最好是大约与喇叭至聆听位置这一块空间的大小相近。这一块地毯的作用在于吸收一些从喇叭射到地板、以及从天花板反射到地板的声波。通常,这块地毯只会对中频以上的频率有效,对于中低频、低频是没有什么吸收效果的。不过,因为它吸收了中频以上的频率,因此也就改变了人耳对于中频以下频率的听感,所以听起来好象整体都会改变一般。
矿纤板便宜好用。再来说到天花板,最便宜的方法就是轻钢架加矿纤板。它的作用主要在适量的吸收中高频以上频段,对于中频以下的频段影响并不大。假若您嫌矿纤板不够好看,也可以请木工用薄夹板做天花板造型。请注意要避免凹型的造型,多做凸出的造型或弧形。因为凹型会使声音聚在某处,而凸型或弧形可以扩散声波。还有一点要注意的,这些天花板上的造型最好不要一整片连在一起,这种作法会使其吸收的频率范围降低,影响了中频段的饱满。正确的作法应该是将天花板分割成几个区,以每区互不相连的原则来设计造型。
六、硬调变软调之后,空间的表面要如何处理将音响空间由硬调转为软调之后,接着可以按照“刘氏好声歌”的原则,以“前硬中吸后扩散”的方法来做表面处理。
喇叭后墙要硬。所谓“前硬”指的是房

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