Professional Subaru WRX STI sound deadening in Sydney. Reducing road noise, vibrations and interior rattles for a quieter and more comfortable drive.
Subaru WRX STI Sound Deadening & Soundproofing
Subaru WRX STI Sound Deadening
Sound Deadening
Subaru WRX STI
2005
AWD
Unwanted vibrations and interior rattles
Poorly installed soundproofing materials
Moisture trapped under old soundproofing
Standard noise insulation
DRY ICE REMOVAL
The old soundproofing material was removed using dry ice — a safe and controlled method that helps separate the material from the body panels without damaging the factory paintwork.
This allows us to thoroughly clean and prepare the surface before installing the new soundproofing system.
REMOVING PREVIOUS SOUNDPROOFING
During disassembly, we found previously installed soundproofing with visible signs of moisture underneath and areas where the material had started to deteriorate.
The old material was carefully removed to inspect the body panels, clean the affected areas and properly prepare the surface before installing the new soundproofing system.
The rear body panels, wheel arch areas and boot floor were treated with vibration damping to reduce road noise and structural resonance.
REAR BODY SOUNDPROOFING
Plastic soundproofing to remove stone drum and reduce road noise
Wheel arches soundproofing
FLOOR VIBRATION DAMPING
The floor and transmission tunnel were treated with STP Aero vibration damping to reduce vibrations and structural resonance across the large metal panels.
This creates the first acoustic layer, helping reduce road and drivetrain noise entering the cabin.
This creates the first acoustic layer, helping reduce road and drivetrain noise entering the cabin.
DOOR CARD SOUNDPROOFING
The door card was fully treated with a sound-absorbing layer to reduce plastic resonance, rattles and unwanted vibrations.
DOOR VIBRATION DAMPING
After removing the old material and preparing the surface, a new layer of STP Aero vibration damping was applied to the door.
The work took 8 days
Added weight: 30kg
Noise insulation level after the work
Listen to the noise after
Reduced noise levels from 59dB to 52dB.
As a result, we get
a 45% noise reduction
a 45% noise reduction
Listen to the noise before
Subwoofer Enclosure
A dedicated HELIX P ONE mono amplifier was installed to deliver powerful, controlled bass to the custom subwoofer system.
Subwoofer Enclosure
A custom-built enclosure was designed for the HELIX subwoofer, delivering powerful, precise bass with a seamless factory-style finish.
A HELIX P SIX six-channel DSP amplifier was installed to provide precise control, tuning and amplification of the front speaker system.
Helix Amplifiers
Custom A PILLARS
Custom A-pillars were fabricated to house Hertz Mille Pro midrange drivers and tweeters, optimising speaker positioning and sound staging.
Speakers Upgrade
Hertz Mille Pro midbass drivers were installed in the front doors to deliver punchy, detailed midbass performance.
New Head Unit
The Sony XAV-9000ES head unit was installed, providing high-quality RCA outputs for a clean audio signal.
The work took 7 days
Audio Upgrade
Heads Unit
Speakers
Subwoofer
- Sony XAV - 9000ES
Speakers
- Hertz Mille Pro
- Helix P Six DSP
- Helix P One
Subwoofer
- Helix 10inch
A quieter Subaru WRX STI. From every direction
Road Noise Up to 10 dB quieter.
Less tyre, road and underbody noise enters the cabin, especially at highway speeds.
Less vibration. More comfort.
High-performance damping reduces body-panel resonance and vibration from rough roads and uneven surfaces.
Better thermal insulation.
Added insulation helps keep the cabin cooler in summer and warmer in winter — ideal for long-distance and off-road driving.
A quieter, more solid cabin.
Reduced exterior noise and panel resonance create a calmer, more solid-feeling cabin for everyday driving and long trips.
Want the same for your car?
Or you can install the noise isolation yourself with our DIY Kits
Leave us a request and we’ll help you choose the best sound deadening solution for your vehicle.
More helpful articles
Full Car Soundproofing
We’ll explain how full-vehicle soundproofing can help achieve maximum noise reduction.
Wheel arches soundproofing
The main source of noise in the car interior while driving is the wheel arches.
We significantly eliminate noise penetrating through the wheel arches, providing comfort and quiet.
Floor Soundproofing
The car floor is one of the most acoustically active elements of a vehicle, so its sound deadening is of great importance.
Sound deadening is one of the most effective ways to reduce noise and vibration levels inside the vehicle.
Doors Soundproofing
Factory door insulation is often limited. A properly designed multi-layer treatment can reduce road noise, vibration and rattles while creating a more controlled acoustic environment for your speakers
Request a quote