The beginning of the sound deadening in the 406 Coupé
A quick presentation
The beautiful Peugeot 406 Coupé, designed by Pininfarina, is already quiet for a car that hit the market in 1997. There was some concern regarding the noise reduction, some simpler sound deadening materials were used, the body of the car uses thick metal sheet and even the glass is quite thick so the pilarless doors are no issue noise wise.
I have changed cars, from my first car, a 106 XSI to this 406 Coupé because I started to drive a bit more in the highway and the 106 was terrible in terms of cabin noise. The car was a Pack version with the JBL sound system and something had to be done to get a better sound quality. I have seen the work of Per Soder regarding sound damping on his Golf, the website is no longer available but an archive still exists.
My interest in having a quiet car was intensifying and I even choose my new tires regarding noise, after a lot of reviews read I choose the Michelin Primacy HP for their good comfort and low rolling noise.
At first I added just some Focal Plain Chant at the back of the front woofers and some Akasa Pax Mate that I had laying around from deadening my computer. The reverb from the bass was gone, but so was some of the bass.
Focal speaker upgrade
Since the JBL's weren't performing to my taste out they went and in some Focal replacements. I am a Focal fanboy, I really love their speakers, the way they sound and the way they are constructed. It's a piece of art.
So, instead of starting at the front I added first the Focal Polyglass 690 CV1 to the back, they mount in the rear parcel shelf. The idea was to add two 6x9" Genesis sub-woofers, but I wanted to keep the original JBL amplifier and that isn't powerful enough.
After this the first noise problem appeared. The rear parcel shelf started to rattle like crazy. I started to search on some forums dedicated to the 406 Coupé and found one guy who was deadening is entire 406. Others where creating new parcel shelf's from MDF but the rattling was still present. So the only way to fix this would be with some Dynamat.
But first, since the front speakers were now lagging behind in Sound Quality I added the Focal Polyglass 165 V1 to the front.
What a difference, the sound stage is now positioned higher, more defined and much brighter. The tweeter is very nice, some say that Focal tweeters are a bit too bright, some guys go for a Focal mid and woofer and opt for a DLS tweeter because of this. I kind of like it as it is.
The front woofers didn't fit, there wasn't enough depth, so I added a plastic ring (should have been made out of MDF, I know) and added a thin strip of foam to avoid any vibrations. It was great, the only vibration was coming from the rear parcel shelf.
Something needed to be done, so I ordered some Dynamat Extreme, Brax eXvibration and started to dampen the car.
Done in 15 of July, 2007