Improvised Noise Insulation on my Grand Espace III

Our Grand Espace III (year 2001) have an average NVH (Noise Vibration & Harshness) level. Means that it is not QUIET enough in my personal opinion, especially compared to the new models and most new cars. Therefore, in my quest to improve this issue, after some search around, find a company that is expert in this issue. KL AUTO owned by Desmond near Jalan Raja Laut KL has done many cars, but seems this is his 1st time doing an Espace.

KL AUTO near Jalan Raja Laut.  More info,
please visit their web http://www.autofoam.com.my/ 

WHAT TO EXPECT?

• For 1st phase, budget about RM800-850 per vehicle (Espace).
• Do not expect much (according to Desmond) because Espace quietness is quite good already
• Grand Espace is less quiet than standard Espace due to bigger size and bigger glass area. 

WHAT BEEN INSTALLED?

• Engine bonnet insulator.
• Front Tyre wheel arch insulation.
• Rear bonnet insulation.
• Under dash insulator. (TEST)

The front engine bonnet noise insulator 

the front tyre insulator

material for rear bonnet insulator. quite heavy and thick.

the rear bonnet before insulator installed.
The rear panel has been removed.

The insulator after installed. 

The under dash insulator material. Sticked below the
aircond hose.

THE EFFECT?
GOOD : Reduce engine noise (about 15-20%) & quieter ambience at stationary & low speed (<20kmh)
NOT GOOD : Tyre noise amplified (hear more tyre noise). Engine noise also feels more noisier especially >65kmh.

WHAT TO DO?
Quite tricky actually. Desmond suggest to remove the under dash insulator. My additional opinion is to upgrade to quieter tyre (now using Michelin XM1)...

WHY THIS HAPPENED?
Noise is quite a complex matter to handle and manage. A near S-Class or Lexus quietness is not easy to achieve in a standard car. Moreover, if our expectation is quite high, a small improvement in that level is simply not enough.

SOURCE OF NOISE/SOUND & HOW TO MANAGE IT

A complex & tricky matter actually. There are 2 main factors of noise; which is actually EXTERNAL and INTERNAL noises. Another matter is our ear will search for noises and sounds, as it is not natural in a no-noise environment.

So, 1st challenge is to block most EXTERNAL noise from entering inside.
The 2nd step is to manage the noises/sounds inside the vehicle. It is quite impossible to eliminate 100% external noises from entering the vehicle. Furthermore, it is not natural for us to stay in a no-noise environment (like in a quiet chamber for torturing people); and for safety purposes.

Basic/fundamental specific car design (such as the top range cars) have better design & insulators to have a quieter vehicle (such as double layer glass, thick insulator, better insulation designs, etc.)

IN MY CASE, HOW THIS MAY HAPPENED?
The more amplified tyre noise has cause more discomfort than before. With less engine noise,  the affect is our ears hear more of "other" noises. Therefore, some of the action can be improvised is to actually increase a little engine noise ; which managing the noise, therefore our EAR will feel more comfortable.

an example of a noisy market

Example : like when we go to noisy market (such as pasar malam), we will hear the noises. However, after a while, the noises become comfortable. When we go back to our home, even the small noise of the white lamp or other small noise can be easily heared, because we come from a noisy environment.

MY ADVISE
The standard insulation of Espace is actually quite good already. However, the 1st phase of this improvement may not yet improvised as expected. I will try to update after the removal of the under dash insulator. Desmond also suggest to go 2nd phase of autofoam (put foam inside the hollow chassis) but for me, I have no issue with the soft handling of the Grand Espace.

So, I will keep you all updated.