Sound Deadening – How to reduce road sound whilst driving
As all Figaro owners know, the sound inside the car compared to any other car is quite loud. We all love the sound the 1-litre turbocharged engine makes, and the lovely exhaust rumble. Sometimes though, it’s nice to listen to some music, particularly if you have spent £400 on a Clarion upgrade. It’s even nice to have a conversation with your passenger (or three!). Reducing vehicle noise in your Figaro however, is not a trivial task. Even a couple of doors or interior panels aren’t going to be done in an hour. You need to remove the interior of the Figaro, depending on how much you are going to do:
- The seats
- All the panels you want to treat
- The centre console
- The carpet
- The door cards
As you will need to unbolt the seatbelts, it’s a great opportunity to clean those, along with your carpet.
Take photographs!
Why? You don’t want to do this twice and you don’t want to be confused about what you are going to do once you remove the interior of your vehicle. When it comes to putting the interior back together, being able to refer to a few pictures to help you is a good thing. You also get a nice photographic record of your work. This may be useful if you decide to sell the car, as it adds value.
How can I tell if adding sound deadening has improved things?
Don’t bother trying the measure decibels. Unless you can set your car up in a controlled environment, there are too many things that can affect the readings. Road speed, weather, other traffic, the list is long.
If you can speak to a p
assenger without shouting, and music sounds better and louder than before with the volume knob turned down. If you can drive the car without getting a headache. These are good ways to measure improvements. Here we look at installing Sound Deadening material into your Figaro to reduce unwanted noise reaching the cabin and your ears.
How does sound deadening work?
When making your Figaro quieter you have three fundamental ways of stopping the unwanted noise reaching the cabin and your ears.
1 – Stop Vibration
Noise from the Figaro’s engine, tyres and general road noise can make the metal panels vibrate. These vibrations are amplified by the resonating panels essentially turning your Figaro into a giant speaker. By applying a sound deadening mat to the metalwork, the vibrations will be damped and the vehicle will seem instantly quieter.
2 – Absorb Sound
Once you have killed the vibrations you need to deal with the airborne noise that is still coming through the doors and floor etc. It is only practical in a vehicle to absorb the higher frequencies therefore a range of foam products are available to apply on top of your damping mats and to fill hollow voids etc. (These foams are also excellent at isolating trim panels that may rattle or squeak)
3 – Block Noise
Low-frequency road and exhaust noise cannot effectively be absorbed in a vehicle as the thickness of foam required would be impractical. You need to block the incoming noise with an effective barrier. The best solution in a vehicle is to use a mass loaded vinyl (MLV). Ideally, this should also be isolated from the panels using a foam decoupling layer. When blocking sound you will need 100% panel coverage to ensure an unbroken barrier layer.
Conclusion
The ultimate solution for your Figaro is therefore to reduce panel vibrations with a sound deadening mat, add a layer of foam absorber and finally a layer of MLV to block the sound.
What products?
There are several products on the market. Dynamat is probably the most well-known, as it features several car restoration TV programmes. However, how these materials are made using the same process no matter which brand you use. Dynamat is imported from the USA, and as a recognised brand, you also pay for the name. For my project, I used Silent Coat, with a Dodo pro barrier.
Mike at The Sound Deadening Shop was a great help when it came to discussing what I needed, and why. He could have easily sold me the most expensive materials, but with his guidance, and their useful website, the whole project seemed a lot easier to do – and at the right price.
THE RECOMMENDED 2 STAGE TREATMENT FOR OPTIMUM NOISE REDUCTION IN YOUR FIGARO
1) Treat the body panels with a sound deadening mat to reduce panel resonance and body boom. Use on all metal panels up to 50% coverage for most cost-effective results.
Recommended product; Silent Coat 2mm Damping Mat. Click here
2) This secondary treatment targets exterior airborne noise that is not directly generated by the body panels. It is a barrier treatment to block unwanted noise intrusion into the cabin from outside. 100% coverage is recommended for the affected areas. Treat the boot and cabin floor to help block road, exhaust noise and tyre roar.
Recommended products;
Dodo Pro Barrier MLV Click here or Dodo Sound Stopper MLV Click here
Cost Estimate (as at October 2014)
Good Quality Treatment
1 x Silent Coat Bulk 40 Sheet Pack
1 x Silent Coat Absorber 15 Bulk Pack
3 x Dodo Mat Pro Barrier
Total approx – £200 (2015)
Comprehensive Treatment
1 x Silent Coat Bulk 40 Sheet Pack
1 x Silent Coat Extra Volume 20 Sheet Pack
1 x Silent Coat Absorber 15 Bulk Pack
1 x Silent Coat Buffler 20
4 x Dodo Mat Pro Barrier
Total approx £300 (2015)
Recommended Supplier: Sound Deadening Shop
Phone: 01865 343934
Website: www.deadening.co.uk
Tower Industrial Estate, Berinsfield, Oxfordshire, OX10 7LN, UK.
