A3 Sportback - Eliminating road noise

Hello!

(Posting this thread here as well, in case anyone from MT recognizes it.)

Since I recently experienced hearing loss, I want to minimize my noise exposure in the future, and that's why I've been looking into heavy foam absorption panels or acoustic heavy-duty film.

However (after already insulating the rear side walls and the lower A-pillars with non-woven fabric and cotton cloths), I believe that truly effective insulation can only be achieved by removing all the interior panels.

Therefore, the question: Does anyone know of a specialized company in the southern German region that focuses on car acoustics and possibly even has experience with the Audi Sportback?

Doing experiments yourself can get expensive in the long run, and I barely have any time anyway, plus, without a hall, nothing really works in the winter.

I would really appreciate any suggestions, feel free to send them as a private message!

Or would it be better to post this in a car audio forum? But I'm not really interested in "loud" systems (see above). It would be great if I could listen to some quiet classical music in my A3.

Or, if you're a "do-it-yourself" type of person: Which areas offer the best return on investment?

My primary concern is the road noise, rolling noise, and droning sounds. The engine itself is running quite quietly (at least on country roads and highways).

Best regards & thank you.
Peter.

Quote:

Primarily, it's about road noise, rolling noise, and droning sounds, while the engine hums quietly (at least on country roads and highways).

I'm sorry, but honestly, I don't think that's necessary, especially considering how quiet it already is.
Modifying a car is almost a pointless endeavor. (It's not like a Ford Escort, where you can almost improve something on every part of it.)

Loud noises, for example, can actually only be eliminated by decoupling components (assuming everything is securely attached to the vehicle).

What definitely makes a difference are quiet tires.
Then I might see some potential for improvement from the inside of the rear wheel arches, but only to a limited extent.
Depending on the age, condition, and mileage of the vehicle, it would be advisable to adjust all the doors and flaps.

The cheapest option would be to use earplugs until your ears return to a normal level of sensitivity.

BM wrote:

I'm sorry, but frankly, I think this is almost a pointless endeavor, especially considering how quiet this vehicle already is [...] The cheapest option would be earplugs, until the sensitivity of your ears returns to normal.

I find – and I found this even before the hearing loss – that the A3 is not particularly quiet, especially regarding road noise. I was surprised by this, because I subjectively felt that my IVer Golf was quieter (I had two more weeks to directly compare them), but it didn't have 17-inch wheels either.

BM wrote:

What definitely makes a difference are quiet tires. Then, I might see some potential from the inside of the rear wheel arches, but only to a limited extent. Depending on the age, condition, and mileage, it would be advisable to adjust all doors and flaps.

Well... unfortunately, the car is new (manufactured in 2007), and there's no rattling anymore (the workshop had to fix it). I already checked the back, and there's quite a bit of bare metal exposed under the side panels. I've already tried to improve the costumes by adding thermal insulation fleece, but it only made a minimal difference.

I'll find out what difference the tires make once I put them on (I'm currently planning to get Michelin PA2 tires).

BM wrote:

Loud noises, for example (assuming everything is securely attached to the vehicle), can actually only be eliminated by decoupling elements.

Do other dampers offer any benefits? Or is it simply the suspension design?

Regards,
Pete.

Hi Peter,

I am also a "sufferer" of tinnitus affecting both ears.

Even though my Golf 3 Variant certainly offers many more opportunities to let loose and have fun, I have to disappoint you.
I've tried a lot of things, and honestly, they haven't really made much of a difference, except maybe providing some peace of mind.

In 2005, I had an A3 Sportback 2.0 TDI for a week with 225/45 R 17 tires, and I can only tell you: be glad! He's incredibly quiet.

However, you'll likely achieve something with more moderate solutions like slippers, specifically small ones around 15 or 16 inches, and certainly more than with large quantities of foam or bitumen mats.

Greetings.
Martin.

dieselmartin wrote:

I am also a "sufferer" of tinnitus affecting both ears.

I offer you my sympathy. I only hear the "hissing" on my left side, but on my right side, I've had poor hearing since I was a child...

dieselmartin wrote:

Even though my Golf 3 Variant certainly offers significantly more possibilities to express its "horsepower," I have to disappoint you. I've already tried quite a few things, and they haven't really achieved much (other than providing a sense of reassurance).

I had already suspected this after my experiments with non-woven mats...

dieselmartin wrote:

In 2005, I had an A3 Sportback 2.0 TDI for a week, with 225/45 R 17 tires, and I can only tell you: Be glad! He's whisper quiet.

Everyone tells me that, but in my case, the sensitivity for certain frequencies must have shifted - or maybe the Dunlop OEM factory tires are just not very good?!?

Well, as a WR, I have 16-inch wheels and a different brand. Let's see; as a *last resort*, I might still end up liking a Lexus IS from a design perspective (I just wonder how they manage to make them so quiet).

Thank you & best regards.
Peter.

I can only think of one thing off the top of my head: installing thicker rubber bushings in the strut mounts. That would help to decouple some of the vibrations. However, the car will then be a bit higher.

You could also take a look at the suspension systems of better-insulated vehicles to see what's different about them in terms of insulation.

As mentioned, the easiest solution is to get new tires. OEM tires are often noisier because they use a different rubber compound (harder for longer lifespan).

If you want to reduce road noise, you can use different axle bushings, for example. These transmit the vibrations from the control arms much less effectively. The same applies to the storage of the support frames.

However, there are a few problems here:
Firstly, it is very difficult to obtain these bushings with a different Shore hardness (we sometimes manufacture them ourselves), and secondly, the handling characteristics become noticeably less precise because the bushings need to be softer.

The A3's more noticeable road noise is simply due to its axle design. It has a lot of control arms, and each of them acts as a vibration transmitter.

At the company where I work, there is a department that deals exclusively with acoustic problems in vehicles. The head of this department has a reputation that is widely recognized throughout Europe.
However, this department does not deal with 'private' individuals, and the investigation and resolution of the issue would be so expensive that you would not want to seek help from us.

Sorry,
Let's see, maybe a colleague will have a good idea that they can share with me in passing.

P.S.: You can only decouple something by breaking the mechanical connections. If you want to decouple the shock absorber from the body, you have to unscrew it and make sure it no longer makes contact with it. Unfortunately, in this case, it's not possible to decouple them.

My old Golf II rattles extremely, and my Bully with the TDI isn't much better; it's been rumbling since I put the TDI in. Fortunately, it doesn't bother me at all because I can't hear it! I'm actually deaf. However, I can feel it, but it doesn't bother me that much. Recently, the exhaust pipe on my van fell off right next to the turbocharger, and I didn't notice anything at all. It was only when the "green men" had to stop me that I realized it. LACH

Jochen_145 wrote:

The fact that the A3 is more noticeable in the road noise is simply due to its axle construction. He just has a lot of control arms, and each one of them acts as a vibration transmitter.

I.e. It's practically impossible to shield it, since the radiation is being directly beamed into the body, and it's also a nice spectral mix?

Jochen_145 wrote:

Let's see, maybe a colleague will have a good idea that they can share with me in passing.

That would be great!

Best regards and thank you for the detailed explanation!
Peter.

Yes, unfortunately, the wheel bearings don't offer any real benefit, and the disadvantages are so significant that you're better off not doing anything further with them.

But, I just came from the Akkusitiker (a type of therapist), and I explained your problem to them:

Here is the translation:

'The following is the result.'

The acoustic problem of the A3 is not primarily caused by body resonance (i.e., vibrations in the axles or body), but rather by airborne noise.
This means that the air surrounding the vehicle acts as a medium for transmitting the rolling noise.
The reason why these sounds are clearly audible inside the car is due to the type of glass used in the A3. These are thinner than those found in other Audi models, and therefore do not provide as good insulation.
To minimize rolling noise, you can do the following:

- Use narrower tires, or 'low noise' tires. However, this comes with a compromise in driving dynamics.

- thicker sevens (but that doesn't really make sense).

- replace the inner fender liners with Filsmat material.

This is quite effective and is, for example, used by Ford. The tire noise is broken up by the fins and not reflected, as is the case with the smooth plastic inserts used by Audi or VW. This already brings some improvement.

You wouldn't need to make any significant changes to the bodywork, as it's already quite good.
You can tell by the fact that very little engine noise is transmitted into the cabin.

Best regards, Jochen.

Can you also glue fender liners to the inner fenders, or do they need to be removed?

Quote:

Can you also glue fender liners to the inner fenders, or do they have to be removed?

I think that should work, as this involves airborne sound and higher frequencies.

Don't you have the option to test different wheels/tires? Ask your , maybe they have something lying around.

To check where noises are coming from, I always drive on "whisper asphalt" in the Netherlands. This type of asphalt almost completely eliminates rolling noise. If it becomes extremely quiet, you should examine your tires closely. If not, at least you'll be able to hear better where the noise is actually coming from. I don't know where you can find this type of asphalt in Germany. I haven't found any other product that's as effective as my test run in the Netherlands (a road through a nature reserve/forest, where there are no distracting noises).

@BM:
The 16-inch wheels and winter tires will be installed next week; I hope they are quiet *even with* the winter tires.

@Mr. Antje:
"Whispering asphalt" isn't available here, but some sections of the track have been newly resurfaced with asphalt, and that significantly reduces the rolling noise. Unfortunately, most of the roads are not in such good condition, and the A3 highway transmits a lot of that noise into the interior of the car.

@Jochen_145:
Thanks again for your help! Those fender covers aren't that expensive, so I'll start experimenting with them. Do you think body adhesive would work to hold them in place? I don't want to get wrapped around the wheels with 200 pieces of felt...

Regards,
Peter.

pschaefer wrote:

@Mr. Antje: "Whispering asphalt" isn't available here, but some sections of the track have been newly resurfaced with asphalt, and that significantly reduces the rolling noise. Unfortunately, most of the roads are not in such good condition, and the A3 highway transmits a lot of that noise into the interior of the car.

Just a quick check to see if you should start with different wheels or if the insulation is worthwhile.

In my experience, my vehicles (my current Passat, as well as my previous A3 from 2000) are relatively quiet, aside from the road noise from the tires. At higher speeds, you can also hear the engine a bit (but mostly when the tires aren't drowning it out -> on quiet asphalt). So, if it were bothering me, I would need to insulate the engine compartment and install different tires. Applying stickers to the fenders would be unnecessary work in my case.

Due to the poor quality of the highways, tires with a higher profile (tread depth) could also reduce the transmission of bumps and unevenness to the vehicle's body.

Regarding "Whisper Asphalt".

My experience with this person is that they whisper to the outside world (the residents), but they yell at me (internally).

The material is rough, which means the sound produced by the rolling motion is absorbed.

But because of the rough terrain, my suspension and tires have to work hard, and that makes noise.

In all the cars I've driven so far, the "Fluesterzeug" material inside was LOUDER than normal carpeting.

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