2006+ Honda Civic Forum banner

1 - 20 of 66 Posts

·
Registered
Joined
·
28 Posts
Hi to all.

I am Rasmus, a more or less happy Civic owner from Estonia.

I bought my car a week before christmas and at first I was pretty happy with things. That probably has something to do with the fact that for the week before that I was forced to drive a rental Daewoo (trust me, its hard to come up with a car worse than that).

The car I had before was a Mitsubishi Sigma, which can more or less be counted as an exec car and has all the comforts: powered everything, auto box, silky smooth ride and a quiet, comfortable interior. So it wasn't long since the first and blind love of the Civic was overshadowed by the amount of noise I would have to put up with while driving. I mean it's OK in the city at low speeds, but having to cover longer distances at high speeds - the road noise just does my head in. Also, driving on rougher tarmac or bad roads (there are plenty of them here) made too much noise, mainly because the dampers used on the Civic are skanky but also because the wheelarches don't have much isolation on them.

So I decided to take some steps against that.

1. Went down to the local car audio dealership and bought some materials: a roll of cotton cloth (its not actually cotton), 4 sheets of 4mm bitumen isolation and 4 sheets of 2mm bitumen isolation. They all have one side in adhesive so it's quite easy to use them, no worries with making them stick. The bitumen sheets are 50cm by 50cm and all add up to about 15kg.
Since the weather here is even worse than it is in England I obviously had to do this inside. The installation instructions for the bitumen mats states that the temperature must be at least 15C for the thinner one and preferably higher for the thicker one, so an industrial blower will be needed unless you do the work in spain.


2. For starters I decided to work the doors. Mainly because I know the panels will come off nice and secondly because that's where the speakers are. And soundproof doors make a hell of a difference in the sound quality. The doorpanels come off after unscrewing three screws and pulling to make the poppers pop. Again, temperature works in your favour with the poppers, if its cold then they have the tendancy to break. Its OK though, they are not too difficult to find and cost little too - just as long as you don't go to find them at your local Honda dealer (where everything apart from the cars tends to be a ripoff). Afer that you will have to unplug the wires for power windows and unhook the cables for doorlocks and the panel is free. Unscrew and remove the speaker, as this area will definately need isolation and the hole is good access to the outer inside of the door.

And here is what is revealed:

ras1.jpg

This is all that Honda bothered to install as soundproofing:

ras2.jpg

And this is the inside of the door panel. Not very impressive, is it?

ras3.jpg

After that you will need to peel the plastic isolation. Be careful here, this tends to get messy as the black glue used to keep this tight makes a mess. You won't need to peel the whole thing off, just make enough space so you can put both of your hands through the door.


3. Clean the inside of the door from any water or dirt. The metal will need to be fairly clean to make sure the isolation sticks and hangs on. Brake cleaner does the job quite well, but be careful, as the sides of the door are sharpish and you can slice your veins pretty easily.


4. Cut out appropriate pieces of bitumen and try them out before heating them up and removing the adhesive. I mainly used 2mm bitumen as it is lighter, but right under the speaker and in the lower part of the door I used both 4mm and 2mm bitumen to ensure better sound quality and minimize vibrations. You can, ofcourse, use 4mm throughout but you don't want to make the doors too heavy - it will wear out the hinges eventually meaning the doors will be harder to close. Also, according to specialists there isn't really a need to cover 100% of the door, they say that 70% of the soundproofing is done by covering 40% of the surface. Heating them up with the blower means the glue is in a better state and you can also mold the bitumen according to the surface - which is neccesary in order to make it stick.

ras4.jpg

The results were something like that:

ras5.jpg

Here is that same speakerhole afterwards:

ras6.jpg

5. Use the cotton cloth or some other soft isolation materials to cover the plastic areas on the inside of the door panel. This will stop higher frequency noises and minimize squeaks that occur when plastic scratches against metal. Keep in mind you don't want to cover up any popper or screw holes. So the inside of the door panel should look like this:

ras7.jpg

ras8.jpg


6. Close the plastic covering, reinstall the speaker, attach the cables, plug in the wires and place the door panel back on. Make sure everything is in place, push the poppers back in and tighten the screws.


I haven't had the means to measure how much the soundproofing changed in decibels, but the doors definately make a nicer sound when closed (there isnt any metallic noise any more) and surprisingly the car feels a lot firmer, smoother and quieter on bad roads. Bumps and potholes don't make as much noise, but mostly - the quality sound is improved greatly. It just sounds cleaner, more powerful and nicer in every way.

The road noise isn't completely solved though - the front and rear wheelarches need same work. I will get to that sometime soon hopefully. Pics and story to follow.
 

·
Premium Member
Joined
·
12,496 Posts
Rasmus, welcome! And what an ace first post.

I really need to get my act together and do this myself. :)

Hope you don't mind, but I've reduced the picture size to keep the post easy to read,
 

·
Registered
Joined
·
28 Posts
Discussion Starter #3
Hi!
Not at all, I realised this after I posted and tried to reduce them myself, but reducing and uploading took a while... So thanks!
 

·
Registered
Joined
·
975 Posts
wow great i look forward to more tips, i wish you lived here as iwould be calling on your services lol
 

·
Registered
Joined
·
28 Posts
Vol2

After doing the doors I still had two sheets of 4mm bitumen and one sheet of 2mm bitumen left and majority of the 1x2m cotton mat was unused, so I decided to continue soundproofing the car from the rear. Seeing many cheaper japanese cars trunks and rear wheel arches I knew that adding soundproofing there will greatly reduce road noise and also create a better surrounding for a subwoofer in the future.

So I started with removing the rear trim.

1. Remove the wheel repair kit (right) and the jack (left).

2. Remove the top (window) shelf.

3. Push the rear seats forward and remove the trim between the seats and the trunk (attached by velcro on the seats and with clips on the trunk side).

4. Use a 10mm wrench to unscrew the bolts two bolts that are revealed next to the hinges of the trunk floor lid.

5. Lift up the trunk floor lid and you will see two caps in each corner of the floor. Remove these with a screwdriver and unscrew the 10mm bolts revealed.

6. Carefully pull off the rear plastic panel around the trunk lock hook, then pulling upwards remove the rear panel.

7. On the right side inside the tyre repair kit pocket you will see two clips. Push these and pull out the pocket which is to the left of them.

8. Right next to the rear doors, on the floor where the seatbelt goes are small panels covering them. Remove them on both sides.

9. Also remove the rear kickplates (the doorsill part).

10. Grab hold of one of the side panels (doesn't matter which one you choose
first), preferably from the rear (the tyre repair or jack pockets are good places to pull from) and carefully pull. There are four poppers holding the panels (three from the top and one right next to the seatbelt hook on the floor). Also be aware that once you get the poppers released you will need to undo the light cable on the right side and the 12V socket cable on the left side. It will seem as though it is stuck but this is merely because the hooks which hold the rear seat in upright position don't want to go through the trim too easily, so you will probably have to give it a little yank.

11. Remove the floor mat.

This is what is revealed:

trunk1.JPG

trunk2.JPG

trunk3.JPG


As you can see, Honda have added a little soundpoofing here, but its not quite adequate still.

As I was unsure of how close the trim and metal were at some places I took great care in selecting the places where I added thicker bitumen and where I had to limit myself to thinner one. Obviously, having the whole area covered will have slightly greater effects but like I said earlier: its not matter of quantity but its a matter of where you add the proofing. So firstly it would make sense to make sure the wheel arches are covered, then move on to other areas. I also added some around the damper mountings as this reduced the sounds that come from rough roads and of course on the floor of the trunk as this space made a horrible noise when knocked on.

After I was done, this is what it looked like.

trunk13.JPG

trunk14.JPG

trunk12.JPG


Job wasn't too well done on my behalf, as I was kind of in a hurry, so I didn't have too much time to bother with measuring and cutting the pieces exact, but they all got attached tight and more or less in the right places.

Likewise here as with the doors, I added extra cotton (somebody please correct me on this, its not exactly cotton, is it?) to the insides of the trim panels. Here's what they looked like before and after:

trunk8.JPG

trunk9.JPG


Once I was done with that you had to reattach all the removed trim in reverse order, making sure all the poppers were in place and wires attached.
Now the car sounds a lot quieter in the back, there is much less road noise there and also I don't hear the rear dampers as often as I did before. But then again, there is still some road noise coming in from the front wheel arches and at high speeds the roof acts like a diffuser to magnify the wind noise, so in the near future I will need to do something about these problems.
So far alltogether I have used 1 square metre of 4mm and 1square metre of 2mm bitumen totalling about 10kg plus 2square metres of cotton, another kilo of weight.

Total spent is just under £40, but I have no clue of what these materials might cost elsewhere.

To do the four doors took about 4 hours, the trunk took about 2,5 hours.
So overall this all is relatively cheap and not much hassle, but the effects are definitely worth it!

To be continued...
 

·
Registered
Joined
·
975 Posts
when i have mine back i shall definatley be doing this, maybe the boot inside the trim as well could be done
 

·
Registered
Joined
·
35 Posts
Spent 6 hours on Sat. fitting Infinity 6510cs upgrade. I also took time to sound deadening the doors. A well worth upgrade,after reading this thread I think I may do the boot next. One tip I have learnt is that you do not have to cover the whole area. Thanks for the info and photos
 

·
Premium Member
Joined
·
1,209 Posts
Nice work Rasmus !
I also did some parts using roof-fix bitumen (except the doors)
For the front wheel arches, you can remove the plastic inner arch and add some bitumen to the bodywork panels, also stuff some isolation in the holes. It is a bit dificult on the right side, since there is the water tank located.
For the rear arches I sprayed some extra layer of bitumen/ruber compount, when the car was new (even before I drove it).
Now I plan to glue some carpet material in the rear arches.
Keep up the good work!

I had a lot of Honda's, despite what you see here, the Civic had the most standard isolation allready in place of all of them...
 

·
Registered
Joined
·
28 Posts
Discussion Starter #10 (Edited)
Vol3 : floor and front wheel arches.

So I had run out of isolation materials and went to a local car audio dealer, where I found a new range of excellent isolation materials. I bought two 60x90cm sheets of the thinnest isolation mats, which cost me about 30 euros. Still had some cotton left, so didn't have to buy any more of that.

1. Remove all of the floor mats. Put the rear seats into upright position. Remove the floor hooks (on the pic below). Philips screwdriver needed.

floor1.JPG

2. Remove the all of the kickplates.

3. Remove the B pillar trim.

4. Remove the front seats (14mm wrench needed). There are four bolts at each corner which can be undone quite easily. After that carefully unplug all the wires underneath the seats.

floor2.JPG

5. Remove the outer side panels in the footwell. Both attached with 2 poppers.

6. Remove the footrest cover (2 poppers) and unscrew the metal part (two 8mm nuts, but need a longer, cylindrical wrench here).

After that, you can lift up the carpet enough to add some soundproofing materials. As there is some already there, I did the areas which were left bare in the factory. Of course, the more the merrier, especially on the wheel arches, but you have to remember, that all the trim and carpets need to be refitted, so you can't add too much.

The most annoying part is doing the front footwells, you have to try to reach as far up as possible but you can't completely remove the carpets or the existing soft sound isolation material there. The front wall is where most of the noise comes from - both engine and road noise from front wheelarches. The rights passenger side is ok to access, but on the drivers side you also have the pedals - and removing those just isn't worth it.

Afterwards you are done (use up all the material you have, especially on the front wall although it is difficult to put anything under the carpet there), just put everything back where it belonged and make sure you don't break any poppers - I busted two attaching the side trim in the footwell. It took me alone 3,5 hours altogether to do the floor and footwells.

floor3.JPG

floor4.JPG

The results - well, I used some newer type of isolation material called "vibroplast", which is a special, light and easily moldable compound that has a folium cover - they claim it to be very effective in a wide range of temperatures. Costs a little more than plain bitumen, but its so much nicer to work with (doesn't really need heating and the glue is much stronger).
Obviously there is lesser road noise, but I had the opportunity to drive a Lexus GS straight after that, and to be honest, that car is still way quieter and more refined in every aspect (the trim doesn't make a sound on bad roads). I know, the price is 3 times higher too, but I admire the work they do at Lexus!

So as far as making a Civic quieter, I have succeeded, but I am not completely satisfied with the results.

To be picky, there are two more things that ought to be done - the roof and some under the bonnet. I will see over the next few days whether or not I can actually be bothered to do them (the roof seems a lot of work).
I have some ideas about the front wheelarches, so hopefully soon this guide will be complete.

But what I do want to do sometime sooner or later is measure the noise level inside my car. I would bet for 4 decibels less, but who knows?
 

·
Diesel Demon
Joined
·
502 Posts
Good work Rasmus. I'm glad someone took the time to take photo's and do a write up, I just haven't got the time/patience/inclination!

You'll find the bonnet really difficult to do, I doubt you'll get the bonnet liner off without breaking the clips, and they're an extortionate price to replace. With a bit of tinkering and some long reach needle nose pliers, you might just be able to close the clips so that they pop out.... Good luck trying.

From experience (did 2 previous cars) soundproofing the bonnet has a beneficial effect, but not quite how you'd imagine. Most of the sound from the engine is transmitted through the bulkhead, so isn't effected by soundproofing the bonnet but some high frequency noise still passes through the windscreen area, which is cut dramatically. However, it will be noticeably quieter outside the car at idle. What you're likely to notice is that there's less wind noise generated through the bonnet as it will be more rigid. (It'll be less prone to huge dents when you hit a fly/stone/feather at speed too!)

You could also try to soundproof the bulkhead, if you can get to it. This will cut noise intrusion from the engine bay into the car interior.

Overall, it adds up to a quieter car. As you've seen, it's not expensive and requires minimal technical expertise. Well done BTW for getting the door cards off with all the clips still attached! That's got to be one of the most stressful car related moments of recent years for me! I must be less patient or more heavy handed than you, because I broke quite a few clips!

Well done again!

Damian
 
  • Like
Reactions: deed

·
Registered
Joined
·
28 Posts
Discussion Starter #12
Thanks Damian, as I said, I am probably not finished with this car yet, so I will hopefully continue this thread soon.
About the bonnet - the results you mentioned are pretty much what I am looking for. Doing the roof should have the same effect of cutting out wind noise and making it firmer - so when bigger rain drops hit the roof it doesn't sound like a drum.
I am also thinking about doing the wheel arches from the outside (not from the interior but from the wheel side). There are some special materials for this, I am still researching this tho.
So in the end, when I am done, this car should ride smooth and quiet, but the engine should still be hear when you push it. Engines make nice noise, whereas bad roads just give me a headache.

Tips for anyone who is planning to improve the soundproofing:
1. Spare enough time. Its not reccomended to remove the trim too many times, as the poppers wear out and since the materials used in a Civic are mainly plastic, they have the tendancy to break. I don't want to know what new door cards might cost.
2. Make sure you have enough of materials. "Too much is never enough" you will always find a spot here or there when you've run out. Adding double layer in most crucial parts (under the speaker or on the wheelarches) will have great effects.
3. Make sure you have some (5 should be enough) extra poppers - cause if you do brake them its best to be able to assemble the car in one go.
4. For the most optimum results, I would start off with doing the front doors and front wheel arches. The trim is easy to remove and you can actually do the footwells without having to remove the seats, so all you will need is a phillips screwdriver and isolation materials (providing you use the "virboplast" i mentioned earlier). 3 sheets (60x90cm) of vibroplast and some cotton will do thejob quite easy.
4. Make sure you don't add too much materials - as the trim might not fit too well later in tighter spaces. And make sure you don't cover up the popper holes!
5. Use good quality materials. There is no point in saving a tenner here. The virboplast I used in vol3 is far greater to work with and has all the better characteristics, plus its as light as the 2mm bitumen. I would, in some crucial places use thicker vibroplast or bimast (yet another compound but thicker and heavier), but if I was to start doing this all over, I would probably not use regular bitumen at all.
6. To understand the results better, do all of the work over the weekend and do not drive the car before you are finished. I did mine bit by bit so its hard to appreciate the hard work :)
 

·
Registered
Joined
·
1,461 Posts
Rasmus,
Well done on a most educational thread. You reckon about a 4db reduction in noise, that's more than 50%, right ?
May I ask a couple of general questions ?
Are the door poppers generally available or do I need the dealers ?
Are there any safety considerations regarding airbags when removing the front seats ?
Thankyou.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #14
Well, 4db is what I think it ought to be. It should be about the same difference as having the balance of the speakers completely faded to one side. The overall sound level inside the standard car should be about 74db at 110km/h, but I will try to get it tested if I have a chance.
About the poppers, I do not know where you could get them from in other countries, but in Estonia there are some shops that sell all kinds of parts for cars, that's where I've found them so far. And the difference in price, compared to the original Honda poppers is about 10 times (Honda originals cost about 2-3 euros per piece).
While removing the seats, after you have unscrewed all the nuts just tilt the seat backwards and unplug the wires underneath it (those are for heated seats - if you have them). I don't think there is anything to do with airbags there. But like I said - you don't neccessarily have to remove them, it makes the floor under the carpets more accessible so you can lift it up more. But if I was to do it again, I wouldnt remove the seats again.
 

·
Registered
Joined
·
111 Posts
ref/Air Bags

Rasmus,
Well done on a most educational thread. You reckon about a 4db reduction in noise, that's more than 50%, right ?
May I ask a couple of general questions ?
Are the door poppers generally available or do I need the dealers ?
Are there any safety considerations regarding airbags when removing the front seats ?
Thankyou.

Hi pcr.
The air bag wiring is under the front seats, just dont turn on the ignition switch, then no problems.
 

·
Registered
Joined
·
56 Posts
Vibroplast

How much Vibroplast would be needed to do the sound isolation as you did Rasmus?

Here in Finland they sell packages including 6 pieces of 450 x 300 mm. They cost 39 € for one package.

http://www.powerset.fi/autohifi/tarvikkeet-a/vibroplast.htm

I have to find someone to do the job for me, because I am totally bad dealing with cars. I am just happy to be able to check the oil and fuel up the car :)

Is there something else to do to isolate the sound even more, or is this method enough to remove most of the road noise?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #18
How much Vibroplast would be needed to do the sound isolation as you did Rasmus?

Here in Finland they sell packages including 6 pieces of 450 x 300 mm. They cost 39 € for one package.

http://www.powerset.fi/autohifi/tarvikkeet-a/vibroplast.htm

I have to find someone to do the job for me, because I am totally bad dealing with cars. I am just happy to be able to check the oil and fuel up the car :)

Is there something else to do to isolate the sound even more, or is this method enough to remove most of the road noise?
To do the whole car (front and rear wheel arches, all doors) you will need 4 big (60x90cm) sheets of vibroplast. And yes, I used the same material they sell in Finland, but here they sell it in two options: package of 6 sheets or big sheets. Plus I would reccomend you also buy some BiMast (thicker stuff) for the critical areas. It wouldnt hurt to do all the floor and the front wall as well.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #20
I wouldn't use too much of bimast. Vibroplast itself is very good but its much thinner and lighter.
If I was to do my Civic over again, this is what I would use:
1 sheet of vibroplast for each door
1 sheet of bimast for each wheelarch
1 sheet of vibroplast for the trunk
1 sheet (I suppose) of vibroplast for the roof
So total of a package of bimast and 6 big sheets (or 4 packages) of vibroplast + some soft isolation material should be enough.
You can always go nuts and do your whole car - like these guys ( http://www.kalliojarvi.net/ibiza/vaimennus/ ), but in the end the more isolation the more weight and like I said, you will never make this car into a luxury vehicle, so in my view there is no point in doing that much. And remember, that reducing sound means reducing vibrations, so its good to use different materials in layers.
For example, road/tyre noise is a lower frequency, so it can be reduced by adding thick, elastic substances on metallic areas (vibroplast) to stop it flooding around the car, but there are also higher frequency noises which are better suppressed by foams, cloth etc.
So remember, its not a matter of quantity, but a matter of smart placement.
 
1 - 20 of 66 Posts
Top