Cx-4 noise insulation construction example sharing, using the recent spare time to do it yourself, about 5-7 hours a day, a total of 10 days, a total of about 60 hours
.
Only after I have done it myself can I know that this work is not so easy
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The modification shop outside may not be as careful as I am
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Especially for the construction of shockproof plate, if I don’t repeatedly roll it in place, the effect will be greatly reduced
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Material purchase list: 1
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16 pieces of nenglang diamond shock-absorbing plate, the remaining one; 2
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6 pieces of 3M sound-absorbing cotton (no gum), the remaining half; 3
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8 pieces of static butyl gum Windsor sound-absorbing cotton, the remaining nearly three; 5
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8 pieces of static butyl gum corrugated sound-absorbing sponge, the remaining 1.5
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Sound insulation construction parts and material Collocation: first, the parts that have not been done, such as fire wall, front and rear floor, ceiling and A-pillar have not been done
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Fire wall is considered to involve too much disassembly, line complexity and other factors
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The front and rear floor of the original car has been made of shock proof and sound insulation cotton sandwich
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The ceiling and A-pillar are equipped with air bag equipment and dare not move
.
1
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Hood: a certain shock absorber + 3M sound-absorbing cotton; 2
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U-groove at the lower end of windshield: a certain shock absorber + local static butyl rubber Windsor cotton, only sticking to the top cover under the windshield; 3
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Triangle area of front vane and front wheel arch: a certain shock absorber + a certain static corrugated sound-absorbing sponge
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Only by relying on the side walls and the leaf plates near the A column, the factory has a stop foam at the center of the leaf plate
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This is the boundary
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The front arch and the leaf plate are not dealt with
.
4
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Four doors: the outer steel plate (a certain energy shock board + a certain static Windsor cotton in the upper half + a certain static corrugated sponge in the lower half); the middle layer steel plate is pasted with a small energy shock board on the outer side, and the hard plastic access plate connecting the glass lifting motor and the track bar is pasted with a small shock board on the outer side; the back of the inner plastic decorative door plate is filled with 3M sound-absorbing cotton
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5
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B-pillar: fill the steel structure cavity with 3M sound-absorbing cotton, and stick the shock plate locally on the inner steel plate
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6
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Trunk door: a certain energy shock board + a certain static butyl rubber Windsor cotton + a cavity three m sound-absorbing cotton ﹥ 7
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Trunk floor, rear wheel arch back box inside + rear seat bottom and facade ﹥ a certain energy shock board + a certain static butyl rubber Windsor cotton + a certain static butyl rubber corrugated sound-absorbing sponge
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The trunk is the largest resonant cavity of the car body, and the exhaust pipe is close to the spare tire pit, which is connected with fixings; the engine vibration in the front cabin is transmitted through the chassis structure, and eventually forms amplification effect in the bottom plate of the trunk and the spare tire pit
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In consideration of the influence of proper control of material weight gain, I did not fully lay the shockproof plate
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Please refer to the construction site photos
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After removing all the trim panels and plastic parts of the trunk, the exposed part of the rear leaf plate should be treated with shock absorption
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Precautions for disassembly: 1
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Buy a box of all kinds of clip accessories in advance, or just buy hood clip, wheel arch plastic plate clip and door panel clip
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2
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Use a plastic pry board instead of a screwdriver
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Be careful to damage the paint or plastic parts and leave dents
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3
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Prepare 10, 12 and 14 kinds of socket wrench (T-type) in advance, and use the sealing plate, wiper head and seat screw in the door panel
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4
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Other tools and accessories: cross screw driver, flat small screw driver, art knife, automotive suede electrical tape, 3M water-proof snake glue (used for the access panel on the door panel), 3M back glue flocking cloth strip (can take the initiative to do anti abnormal noise treatment for the edge of some chassis plastic shell), shockproof plate roller (one end is very practical with a single row of small rollers), and a strong scissors Knife, tape measure, coarse cotton thread gloves, etc
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Feelings before and after the construction: the tire and wheel hub have not been replaced, the original 19 inch Feihua wheel hub + yukohoma tire
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After all the above processes are finished, I specially go for a section of high-speed trot
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For the old high-speed, most of the roads are light colored, and the small section is dark colored
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At the 20km section of the expressway, the audio is turned off on one side of the way, Carplay is only connected to the navigation, and the music is turned on on on the return Carplay with the volume of 16
.
1
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The change of the opening and closing sound of the four doors and the trunk door is inevitable, because the vibration frequency of the steel plate is changed, the vibration intensity is suppressed, and the closing sound becomes dull and firm
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To put it bluntly, the sound of door closing has become like a C-class car
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2
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Sound effect: the original car has its own Bose eight speaker system
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For any upgrade, keep EQ setting unchanged, and maintain the volume of 15-20
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The sound has become transparent and pleasant
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Specifically, in the past, the low-frequency turbidity has been significantly suppressed, and the low-frequency intensity has been significantly improved
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EQ needs to be reduced by one space on the original basis to stop banging
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The whole sound field has become more open
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Conclusion: I am very satisfied with the improvement of sound effect
.
3
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In the low-speed start-up stage, the unexpected thing is that the engine sound becomes clearer than before, that is, only the engine sound of lightly stepping on the accelerator is obviously felt
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It’s the kind of engine sound Mazda deliberately appeals for
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In my subjective analysis, the reason for this change should be that the sound insulation of the four doors and other parts reduces the noise source from outside the car body
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In the high-speed section, the tire noise on the old road surface is still obvious, but it is not like the slightly irritating mixed high decibel noise before
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The difference between the noise levels of 100 and 120 per hour is not obvious
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To be frank, the previous experience of judging speed based on noise is not very effective now
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When you accidentally go up to 120, you feel that the noise level is almost the same as that of 100 or even 90
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Once in a while, when you enter the newly paved road section, the tire noise is extremely comfortable at 110-120 H
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At the same time, the sound volume remains unchanged for 16 hours, so there is no need to increase the volume to suppress the influence of noise on listening
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The engine noise is mixed with other noises and can not be distinguished
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In this way, the noise suppression effect at high speed is more significant
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When it comes to oversized goods, you can obviously feel that the huge noise from the truck has become much smaller
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This shows that the sound insulation transformation has a good suppression effect on the environmental noise
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Another intuitive feeling is that when the four windows and skylights are fully closed, the wind noise from the front bumper, roof and side windows can be clearly heard at 110 / 120, which is a slight wind blocking sound
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This should also be one of the “amplification” phenomena when other noises are properly suppressed
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I don’t plan to deal with the firewall in the later stage
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Now the engine sound that comes to my ears at high speed doesn’t make me uncomfortable
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There is no low-frequency resonance that may appear on the shock absorbers that were concerned before
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It is true that there is no low-frequency resonance from the start to 130
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No matter how high the speed feedback, I didn’t try
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I didn’t overspeed
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There was no need to test
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The total cost of materials, accessories and auxiliary tools is 4000 yuan
.
The surplus materials are about 400 yuan (more than 200 yuan can be recovered from salted fish processing)
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The actual material cost is about 3700-3800 yuan
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It takes about 60 hours
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The weight of sound insulation material is increased by 32 kg and the weight of the car is 1600 kg
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This car is mainly used in Tibetan areas
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It is basically paved on national roads and a few expressways
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Now there are fewer and fewer pure dirt roads left for cross-country enthusiasts
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Even the Chayu chawalong section has to be paved with oil
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There are many mountain roads in Tibetan areas
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From Kangding to Lhasa, there are more than ten high-altitude passes
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In the past 16 years, the 1.8-year-old corolla turned back and the mountain road was feeble.
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