Car audio modification concept

Car audio modification - modifying and upgrading the original car audio system to improve the sound field environment and sound quality in the car to satisfy the car owner's "music needs" Fever" demand.

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Car audio information

According to statistics, the cost of primary car audio modification is 1,000~ Prices range from 7,000 yuan, and some car owners will put price first when choosing car audio. Most car owners admit that they are not "audio enthusiasts" in terms of audio. They would rather spend a little money to improve the sound field environment and sound quality in the car. Therefore, when choosing car audio or modification shops, they often "choose whatever is cheap." . However, "you get what you pay for" is not unreasonable.

Under normal circumstances, the price of a product will be directly proportional to the function and characteristics of the product. Car owners must clearly understand their own needs and consider a reasonable price in order to buy high-quality and low-priced car audio products. It is worth mentioning that in order to ensure driving safety and minimize the interference of in-car equipment, everyone will have higher requirements for in-car equipment, so car audio with good performance will be more expensive than home audio. The world-famous car audio brands include: Dynaudio, Harman/Kardon, Burmester, BOSE, Bowers amp; Wilkins (B amp; W), Bang amp ; Olufsen (B&O) et al.

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Why you should modify your car audio

As we all know, urban traffic congestion can keep drivers mentally distracted Nervous state, fatigue and sleepiness increase the risk of driving, and pleasant music can effectively relax tense nerves. The competition in the automobile market is becoming increasingly fierce. Manufacturers have increased R&D costs in terms of appearance and power performance. Under the pressure of cost control, the original car's audio system is the first to bear the brunt: in the production and development process of the original car audio system, they do not pay attention to professionalism and pursue low cost. As a result, Poor sound effects. A good horse deserves a good saddle, and beautiful music requires a high-quality sound system and speakers. It is very necessary to modify the original car sound system.

Car audio modification steps

1. Know your favorite music style

Some car owners believe that good quality speakers must be suitable for all styles of music, but this is not the case. . Music is special, and car audio manufacturers produce different types of speakers corresponding to different music styles. For example, the R6.2 speaker of "DLS" has super sound quality restoration ability, and the vocal interpretation is very pure, while the RM6.2 speaker of the same brand is more suitable for performing large dynamic music because of its mid-range. The bass performance is strong and the penetration is sufficient. So you must know what kind of music you like, which is very important for car audio modification!

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2. Everything should be based on reality and seek truth from facts

As the saying goes, "How big is the picture?" Shoes are as big as your feet are." The same goes for car audio modifications. 2,000 yuan can be used to modify a set of car audio, and 500,000 yuan can also be used to modify a set of car audio. Car owners should modify and upgrade their cars according to their actual conditions and do what they can. They must not put too much pressure on themselves for the sake of so-called vanity, which will result in more losses than gains.

3. Choose a formal and professional car audio modification shop

In fact, most of the domestic car audio modifications are carried out in car beauty shops or car decoration sales stores, where the technicians Basically no modification experience. They often over-promote related equipment and products to car owners, making car owners who originally know little about car audio modifications think that this is "everything".

In fact, the audio modification process includes many steps. Car owners can judge whether the car audio modification shop they are looking for is formal and professional from the following aspects:

1. Whether the modification technician really wants to understand your needs

2. Whether the modification technician understands the characteristics of sound

3. Whether the sound insulation construction is rigorous and whether there will be any abnormal noise after construction

4. Whether the selection of wires and insurance are reasonably matched

5. Is the installation process of the speaker exquisite and is it a non-destructive installation?

6. Is there any professional audio debugging?

7. Is it affected by the modification? Car Warranty

Even the same car audio product may have different effects if installed by different technicians. It can be seen how important it is to choose a regular and professional car audio modification shop! The editor's suggestion is that before choosing a modification shop, car owners should find ways to check the reviews of different customers on the shop in advance, or go to the shop in person to take a look at the merchant's construction process so that they know what they are doing and save unnecessary trouble.

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Generation of vehicle noise

Sound is produced by vibration. When the vehicle is driving There will be a lot of vibrations. The engine will vibrate, the exhaust pipe will vibrate, the friction between the body and the air will vibrate, and even the vibrations caused by the friction between the tires and the ground will be transmitted to the car through the suspension, all of which will cause noise. The scary thing is that if the natural frequency of some parts of the car body coincides with the frequency emitted by these vibration sources, vibration will occur (vibration is one of the important reasons for premature aging of the vehicle), and After the vibration, greater noise will be produced.

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The concept and principle of car sound insulation

Car sound insulation products are developed by a group of American car audio enthusiasts It was developed collectively by authors in the late 1980s in order to enjoy the fun of car audio in a better and more detailed way. These car sound insulation products can not only help reduce the noise generated by the vehicle while driving, but also improve the sound pressure and tone of the car audio. It can be said that it kills two birds with one stone. However, there are pros and cons. Sound insulation modifications to a vehicle will increase its fuel consumption and weight, and the drainage function of the windows will also be affected to a certain extent, making the door panels more likely to rust.

Generally, sound insulation and noise reduction can be achieved by reducing vibration or absorbing sound. There are currently four popular processing methods.

First, increase the damping coefficient of the car body through shock absorbers and reduce noise at the sound source.

Second, use sound-absorbing cotton to absorb noise.

Modification technicians usually use a combination of these two methods, that is, first affix a layer of anti-vibration panels to the car body, and then a layer of sound-absorbing cotton on the anti-vibration panels (sound-absorbing cotton is used when there is a cavity) The effect is more obvious where the body is located). Modification technicians may also lay a hybrid material called "Low Frequency King" directly on the car chassis to reduce low-frequency noise.

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Third, double-layer soundproof glass is modified to directly isolate the noise outside the car.

Automotive sound-insulating glass usually uses laminated glass with a double-layer composite structure, and the sound-insulating damping glue (film) in the middle of the laminated glass plays a role in weakening the transmission of sound and can directly and effectively isolate the noise outside the car. . The well-known Buick LaCrosse, Cadillac ATS-L and other luxury models all adopt double-layer soundproof glass design. The worst thing is that most car soundproof glass is specially designed for cars and is difficult to buy on the market.

Fourth, replace with comfortable and quiet tires to reduce tire noise.

The tires equipped with the original car usually take into account cost, grip, fuel consumption and durability. Comfort and silence may not be taken into consideration at the same time. Especially some sports tires and run-flat tires, the tire noise is comparable to rock music. At the concert site, directly replacing a set of silent and comfortable tires is the most effective way to reduce noise. The principles of silent tires of different brands are basically the same, which is to use special designs of tire patterns, structures and materials to reduce tire noise.

Some of the more excellent silent tires on the market include: Goodyear Imperial II, Continental MC5/CC6, Pirelli's new P7, Michelin Haoyue 3ST, etc. Silent tires usually have softer treads. Compared with sports tires, they have weaker grip performance, shorter lifespan, and slightly higher fuel consumption

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Car sound insulation steps

Systematic car sound insulation treatment generally includes three steps: shock absorption, noise reduction and sealing. Only building a firewall will not achieve better sound insulation effects.

Most of the noise is transmitted into the car through the car's suspension system, trunk, chassis, doors and other parts, so the first step is to dampen the four doors and trunk. , and then complete the shock absorption treatment of the car floor, engine compartment and roof in sequence. The second step is to perform sound absorption and noise reduction treatment on the entire vehicle. The third step is to seal the interior of the car body. Be careful not to over-seal when sealing the interior of the car body. The car body sealing project is the basic project to reduce the noise transmitted from the outside to the inside. Excessive sealing will cause lack of oxygen in the car and cause harm to the body of the car owner. Therefore, the modification technician should maintain good sealing of the car body while maintaining the air pressure in the car. balance.

General sound insulation projects can reduce noise by 2-3 decibels. Choosing good sound insulation materials can reduce noise in the car by 5-8 decibels. In the best case, it can even reduce noise by 13 decibels. If the construction workers tell you that they can reduce the noise by 20 decibels after completing the sound insulation treatment, then you need to think about whether you have been deceived.

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Selection of sound insulation materials

The anti-vibration board is divided into two parts, namely aluminum foil and glue layer. Genuine rubber layers will be made of environmentally friendly materials, while defective products will be replaced by asphalt. The material of the genuine rubber layer is mostly butyl rubber, and the temperature has very little effect on its state. It will maintain the same state as plasticine during the shelf life. In contrast, asphalt, temperature has a great impact on its state. There may seem to be no problem when the temperature is low, but when the temperature is high, the asphalt will melt directly and emit various toxic gases, making it absolutely unsuitable for use in cars. Because asphalt is cheap and its form at normal room temperature is very close to rubber, some unscrupulous manufacturers will make inferior adhesive layers and pass them off as good ones, confusing customers.

Is there any way to distinguish the authenticity of the materials? The editor will teach you now!

Method 1: Tear off a small piece of glue layer and knead it in your hands. If it's asphalt, your hands will be left with stains that are difficult to remove, but if it's butyl, your hands will still be clean.

Method 2: Tear off a small piece of glue and burn it with fire. The state of asphalt is very unstable and will melt immediately when exposed to high temperatures. Therefore, the defective adhesive layer will support combustion and gradually turn into liquid when exposed to fire. If it is butyl rubber, it will need to be in a continuous fire state for a period of time before it will burn by itself and will not support combustion.

Misunderstandings in car audio modification

Myth 1: Data comes first, the bigger the wattage of the speaker, the better

The editor found that many car owners’ concept of car audio modification is , the bigger the wattage of the speaker, the better. Actually, there is no best, only the most suitable. Why do you say that? On the one hand, the original 95 cars do not have independent power amplifiers. In other words, the speaker units in the car are driven by the smaller power integrated power amplifier in the host computer. The original car's host computer is divided into two types: CD and DVD (there are also ones equipped with MP5, let's classify them as DVD). The peak power of CD is generally within 30W, and the peak power of DVD is generally within 50W. In terms of rated power, Both are generally around 20W. Under normal circumstances, the modifier will recommend that the power of the selected amplifier is slightly larger than the power of the speaker, and the power of the modified speaker basically starts from 40W (the rated power of the speaker is defined as the power that the speaker can continuously withstand. Note , is continuous endurance, rather than continuous need).

Today’s market is full of confusion. Many well-known brands boast that their speakers have a rated power of 90W (as shown below). Please do not believe it.

Therefore, it is basically impossible to configure speakers according to the thinking of "the bigger the wattage of the speaker, the better". On the other hand, high-power speakers require special equipment (DSP) to drive them, otherwise they will not be able to perform as well as they should. In addition, the editor would like to remind all car owners that the power marked on many products is actually false. Merchants all know that "the greater the power, the higher the price." Taking advantage of the "data first" psychology of car owners, marking higher than actual power can allow them to earn more profits.

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In addition, the speaker also has a very important but often ignored parameter - sensitivity (speakers with a sensitivity of 90db It can be regarded as a high-quality speaker). This is the data that beginner car audio players should pay most attention to, because sensitivity can tell you whether the speaker is easy to drive.

Myth 2: Modification is a very simple matter

In the eyes of most people who do not understand car audio modification, changing speakers is as simple as changing a mobile phone case. Loosen the original car speaker screws, install the new speakers, and you're done! But that's not the case. Basically, all the original car speakers are integrated with the original car speaker gaskets, and they also fit closely with the sound guide cover on the door trim panel, so they cannot be easily removed. Here, the editor will introduce you to the correct speaker installation steps.

1. Observe whether the tweeter is on the door panel. If not, consider where the crossover is most suitable.

2. Carefully remove the door panel, and then remove the original car speaker.

3. Measure the height and diameter of the washer of the original car horn, and calculate how many washers are needed for the new horn. If the gasket cannot adjust the new speaker to the ideal height, a new sound guide will be made to fit the original door trim.

4. Waterproof the gasket and install a waterproof cover on the speaker.

5. Determine the installation position of the crossover to ensure that it can avoid interference. (There is an inductor coil in the frequency divider, which can easily pick up surrounding electromagnetic signals and cause interference)

6. Carefully route the wiring.

7. After the installation is completed, use large dynamic music to test whether the modified speakers have vibration phenomena and use a phase meter to test whether the phases are consistent.

Car audio is different from home audio. Without formal and professional modification technical support, even the best host, speakers and amplifiers will not be able to exert their true strength.

Myth 3: The more expensive the audio equipment, the better

Although the editor has repeatedly emphasized that "you get what you pay for", the more expensive the audio equipment, the better. Car owners should choose equipment based on their actual situation and needs, and act within their capabilities. Don't blindly choose high-priced ones out of vanity, and don't blindly choose low-priced ones just because you are greedy for petty advantages. In fact, for junior car audio modifiers, even if they choose audio equipment from some well-known brands, the overall modification cost does not need to exceed 10,000 yuan.

In addition, under normal circumstances, the construction fee for installing speakers will be around 300-500 yuan. If the overall price of the car audio package (including installation) you choose is too low, you have to consider whether the merchant has cut corners in the manufacturing of the product and deceived customers. For example, if you purchase a six-speaker, two-way car audio set (installation included), but its retail price is less than 900 yuan, then the risk of you making a mistake will be very high.

Myth 4: Blind pursuit of "foreign brands"

Many car owners have a "foreign brand complex" and feel that foreign brands must be better than domestic ones, but this is not the case. Many excellent audio products are made by domestic brands, and the vast majority of "foreign brands" are actually produced in China. Nowadays, the car audio market is a mixed bag. Many small brands have been "gilded" abroad through certain channels and come back, claiming that they have decades of history and have produced countless high-quality products. Because they know that by taking advantage of the car owners' "foreign brand complex", no matter how shoddy the product is, they can attract more customers.

Whether it is a foreign brand or a domestic brand, as long as it meets your requirements, it is a good brand.

I hope that car owners will not just listen to other people’s evaluations of audio, nor blindly pursue foreign quality, because everyone’s understanding of music is different. Only after you try it out for yourself can you judge whether this car audio is suitable for you.

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Myth 5: Being carried away by the cool product packaging

At present, the product The phenomenon of excessive packaging is becoming increasingly serious, and many packages have deviated from their proper functions. Too many consumables, too heavy weight, too large volume, too high cost, and too gorgeous decoration are all characteristics of excessive packaging. The editor once came across a car amplifier with a very high-end package. The wooden box is covered with leather, lined with scarlet velvet, high-count knitted white gloves, and the amplifier is packed in a blue velvet bag. This kind of packaging makes people feel that the product is very high-end. . But if you think about it carefully, why do manufacturers put so much effort into the packaging of their products? It is nothing more than creating a gimmick and winning the favor of car owners on their first impression of the product. The editor does not mean that the quality of a packaged product must be bad, but that car owners must clarify their modification goals, correctly evaluate the product's cost performance, and carefully listen to the sound effects, so as not to be dazzled by the cool product packaging and find the A speaker that satisfies your musical pursuits.

The above-mentioned misunderstandings about car audio modification by car owners are listed to illustrate that car audio modification is not a single link, but a perfect combination of equipment, technology and art. Vanity is a must, quality is the last word.

The principle of car audio tuning

Car audio tuning plays an important role in the performance of car audio products, just like a gun, if its sight is not calibrated , the bullet fired must also be deflected. In fact, to create an "emperor's position" in the car, what we have to do is to use various soft and hard tuning methods to make the car audio balanced on the left and right sides, with a clear sound field focus, and each speaker unit with accurate and good signals. The effect of connection.

How is "stereo sound" formed? On the one hand, two sets of speakers on the car, one on the left and one on the right, are required to synchronously send audio signals to the left and right ears of the person respectively, so that the person's auditory nerves can "focus" on a three-dimensional sound field. On the other hand, although the signals of different frequency bands are "integrated" when recording music files, in actual playback, they are often played by multiple speakers of different frequency bands. Therefore, if you want to truly restore the sound quality, you must accurately connect the signals from each speaker unit. In addition, the installation conditions of car audio are much more complicated than those of home audio, which greatly increases the difficulty of car audio tuning technology and highlights its importance.

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Why car audio tuning is necessary

The tuning principles followed by home audio, in The same applies to car audio. But compared with car audio, the tuning conditions of home audio can be said to be very ideal. Why do you say this?

First, due to seats, the distance between passengers and each speaker is different, which inevitably means that the positioning of sound by passengers will shift to the left or right.

Second, in the car, speakers can often only be installed on the A-pillar, triangular position, door panel, etc., and cannot be kept on the same cross-section like home audio. Doing so is not only easy to produce various vibrations, but also makes the sound quality of the speaker uneven and the sound lacks integrity.

Methods and steps for car audio tuning

Preparation work:

1. Restore all additional functions of the host to factory settings

2. Center the high, mid, bass and left and right balance

3. Set the GAIN (gain control) of the power amplifier to MIN (minimum value)

4. Set the FILTER( Filter setting) to OFF

5. Set CROSSOVER (cutoff frequency) to MIN (minimum value)

6. Follow the same steps for the subwoofer amplifier

Formal tuning:

1. Host debugging

Turn on the host, play a high-fidelity vocal disc or an audition disc with strong bass dynamics, and adjust the host volume Turn it to 1/2 or 3/5 of its maximum volume, which will make it easier to stimulate a rich bass.

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2. Front sound field debugging

First adjust CHANNEL1/2 to an acceptable level for you Maximum volume, then turn down the volume of the host, put in a vocal disc or a strong low-frequency audition disc, and finally increase the volume of the host slowly (just slightly louder than the normal volume). After completing the above steps, listen carefully to see if the vocals on the speaker are clear and if there is any nasal sound. If the sound is clear, the low frequency is crisp and powerful, full of elasticity, and there is no "buzzing" sound, then congratulations, your front door's sound insulation and shock absorption effect is basically perfect. In this state, your front door mid-bass will perform at its best.

3. Power amplifier debugging

"Vibration" generally occurs when the volume of the host is turned up. It will not only offset many details and distort the sound, but also weaken the elasticity of the low frequency. , we can reduce the probability of vibration through the CROSSOVER (cutoff frequency) on the power amplifier. Note that FILTER (filter setting) and CROSSOVER (cutoff frequency) are used in combination. Only when FILTER (filter setting) is in LP (low pass) or HP (high pass) state, the adjustment of CROSSOVER (cutoff frequency) will be effective.

We first set the FILTER (filter setting) to the HP (high-pass) position, and then adjust the CROSSOVER (cutoff frequency) to 60-100HZ. If when the original sound is not clear and the CROSSOVER (cutoff frequency) is adjusted to 60-70HZ, the hazy feeling of the human voice disappears or the low frequency does not have a "buzzing" tail sound, then congratulations, your sound insulation and shock absorption are still the same. Well done.

PS: The editor will explain the meaning of LP (low pass) and HP (high pass) here.

If the FILTER (filter setting) is in the LP (low pass) state and the CROSSOVER (cutoff frequency) is adjusted to 70HZ, it means that frequencies above 70HZ will be filtered out and cannot be output to the speaker. , so LP (low pass) will also be applied to the subwoofer. On the contrary, if the FILTER (filter setting) is in the HP (high-pass) state and the CROSSOVER (cutoff frequency) is adjusted to 70HZ, it means that the low frequencies below 70HZ will be filtered out and cannot be output to the speaker.

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4. Rear sound field debugging

First dial FILTER (filter setting) to HP (Qualcomm) position, and then adjust the CROSSOVER (cutoff frequency) to about 150HZ. Next, turn up the volume of the main unit (just slightly louder than the normal volume), and finally turn up the volume of the power amplifier. As long as you can "feel" the sound in the rear sound field while sitting in the front row, it will be fine.

5. Bass debugging

It is best to debug the bass by two people, one listening in the car and the other adjusting behind. Bass adjustment is the key to car audio tuning. If it is adjusted well, it can make the audio even better.

We first set the FILTER (filter setting) of the bass pushing amplifier to the LP (low pass) position, adjust the CROSSOVER (cutoff frequency) to MIN (minimum value), and then set the GAIN (gain control) ) to half or 3/4 of the front sound field, then increase the volume of the host (just slightly louder than the normal volume), and finally put in a strong low-frequency audition disc to start debugging. If the bass is hazy and muffled, it means that the GAIN (gain control) is too high and needs to be turned down quickly.

After adjustment, slowly increase the CROSSOVER (cutoff frequency). Under normal circumstances, the bass will gradually become stronger and harder as the CROSSOVER (cutoff frequency) is increased, and the positioning will slowly move forward. When the CROSSOVER (cutoff frequency) reaches a certain critical point, you will suddenly find that the bass is combined with the low frequency of the front sound field, that is, the low frequency is no longer emitted from the rear row, but merged with the speakers of the front door. This The point is the connection frequency between the woofer and the front door speakers. Note that the GAIN (gain control) of the bass must be adjusted together with the CROSSOVER (cutoff frequency), which is also the most difficult part of car audio tuning.

At this point, the entire car audio tuning comes to an end. As you can see, completing car audio tuning requires not only time, but also the tuner's meticulous and patient working attitude and professional and formal technical support. I hope that all car owners can understand the importance of tuning, feel more music and grow slowly in the process.

Summary