08-12-2011, 11:32 AM
This is a guide I'm going to be writing over the coming weeks as i finish it off.
About sound deadening
Most people think that sound deadening such as dynamat absorbs sound waves and pressure and as such means panels dont rattle. This is true but not entirely.
The main difference is made by 'weighting' the panels. Taking a car door for example, the outer skin of the door is no more than 2mm thick on most cars. When you consider that you probably have about a square metre of area on the front doors of a 3dr 306 with no real support in the middle, it's going to mimic the cone of the speaker to a small extent. This causes rattles!
The idea behind weighting panels with bitumen sound deadening is that it adds dead weight to the panels meaning the air pressure created by the speaker in the enclosed space (door) is not enough to reverberate against the panel.
Not only does sound deadening give good sound proofing properties but it also helps with keeping warmth in, in the winter, heat out in the summer and also helps to reduce road noise. What it DOESN'T help with is weight! Bitumen is a heavy material and as such, if you plan on doing the entire car, you will probably be adding around 15-20kg to the weight. The other downside is its expensive! To do the entire cabin of a 306, you will be looking at about 160 quids worth of silent coat (a cheaper but just as good version of dynamat).
There is a way around this though! Areas such as the boot floor, floor of the car etc don't really require bitumen sound deadening (unless you are going for a very expensive SQ build). These areas are generally thicker metal but are also shaped (instead of being one flat sheet of steel). This means these areas don't really suffer from rattles however they do let a lot of road noise in which most people don't realise, makes a huge difference to SQ. Peugeot have put sound deadening material on these areas but it's cheap, heavy and doesn't really do much other than soak up water and go moldy.
This is where cloud 9 comes in!
Cloud 9 is a carpet underlay with a difference. Unlike most underlays it's sound proofed to a rating of 45Db. It's also made out of PU foam instead of the traditional rubber carpet underlay you may find in your house. The benefits of cloud 9 are it's very light, very versatile, great for sound deadening and a lot cheaper then bitumen sound deadening (I've just payed 69 quid for a roll of 15sq metres. Enough to do 2 cars!). The only downside is its chunky. They offer 2 thicknesses, 7mm and 9mm. Both are rated to 45Db so there is no performance difference. Only difference is feel underfoot which isn't a problem for us unless that bothers you in your car!
Throughout this guide I will be using a mixture of cloud 9 and silent coat to get the best of weight saving, sound deadening and money saving!
About sound deadening
Most people think that sound deadening such as dynamat absorbs sound waves and pressure and as such means panels dont rattle. This is true but not entirely.
The main difference is made by 'weighting' the panels. Taking a car door for example, the outer skin of the door is no more than 2mm thick on most cars. When you consider that you probably have about a square metre of area on the front doors of a 3dr 306 with no real support in the middle, it's going to mimic the cone of the speaker to a small extent. This causes rattles!
The idea behind weighting panels with bitumen sound deadening is that it adds dead weight to the panels meaning the air pressure created by the speaker in the enclosed space (door) is not enough to reverberate against the panel.
Not only does sound deadening give good sound proofing properties but it also helps with keeping warmth in, in the winter, heat out in the summer and also helps to reduce road noise. What it DOESN'T help with is weight! Bitumen is a heavy material and as such, if you plan on doing the entire car, you will probably be adding around 15-20kg to the weight. The other downside is its expensive! To do the entire cabin of a 306, you will be looking at about 160 quids worth of silent coat (a cheaper but just as good version of dynamat).
There is a way around this though! Areas such as the boot floor, floor of the car etc don't really require bitumen sound deadening (unless you are going for a very expensive SQ build). These areas are generally thicker metal but are also shaped (instead of being one flat sheet of steel). This means these areas don't really suffer from rattles however they do let a lot of road noise in which most people don't realise, makes a huge difference to SQ. Peugeot have put sound deadening material on these areas but it's cheap, heavy and doesn't really do much other than soak up water and go moldy.
This is where cloud 9 comes in!
Cloud 9 is a carpet underlay with a difference. Unlike most underlays it's sound proofed to a rating of 45Db. It's also made out of PU foam instead of the traditional rubber carpet underlay you may find in your house. The benefits of cloud 9 are it's very light, very versatile, great for sound deadening and a lot cheaper then bitumen sound deadening (I've just payed 69 quid for a roll of 15sq metres. Enough to do 2 cars!). The only downside is its chunky. They offer 2 thicknesses, 7mm and 9mm. Both are rated to 45Db so there is no performance difference. Only difference is feel underfoot which isn't a problem for us unless that bothers you in your car!
Throughout this guide I will be using a mixture of cloud 9 and silent coat to get the best of weight saving, sound deadening and money saving!