Knew that I wanted to do this mod this spring so got at. Had read with interest all the threads on the forum , had done my previous sports car with guidance from an expert in sound deadening in vehicles.
I used Dynamat Extreme (butyl rubber) as a I prefer it over asphalt based products such as with Fatmat. Butyl always remains pliable, will never dry out. Over the Dynamat I added a closed foam cell application (Frost King Duct Insulation available at HD or Lowes ) to sound proof the bulkhead behind the seats and the rear of the car. Dynamat or similar products stop the low frequency noise best thru absorbing vibrations in the panels, closed cell foam absorbs the midrange and higher frequency sound waves. Put down the Dynamat first then the foam, the Frost King foam has a sticky side as well.
I focused a lot of time on the wheel wells as we all know the tires generate a lot of road noise up into the trunk area. Aside from the Dynamat and foam I also put acoustical insulation (Roxul insulation) in behind the sidewall speaker wells to fill those gaps.
Those speakers are just behind your head and there is a ton of open space that can echo sound up directly from the wheel well, that is now closed up. Odd that I noted on the right side they had already put some acoustical material in the space but none on the drivers side, almost like it got missed during assembly. Obviously GM recognized this area transmits sound from the wheel well up to the driver, too bad they wouldn't be a little more generous with the insulation they put in and apply it to both sides. I literally filled the cavity, bonus of better sound now from those speakers as well.
The noise elimination is significant. My wife who has no play in the game , no panacea effect, she couldn't believe the difference when I took her out yesterday. I would say the road noise from the rear is half of what it was and now very comfortable. No I haven't measured it with a DB meter but don't need to it was a substantial improvement no doubt. Stereo , you hear a lot more depth , more base. The doors and hatch a little tougher to close as the car is tighter so far as air movement. Well worth $250 and about 6 hrs of my time. Here some pics... I took the last pic before applying the Frost King over the Dynamat in the trunk. The wheel wells took by far the most time.
I used Dynamat Extreme (butyl rubber) as a I prefer it over asphalt based products such as with Fatmat. Butyl always remains pliable, will never dry out. Over the Dynamat I added a closed foam cell application (Frost King Duct Insulation available at HD or Lowes ) to sound proof the bulkhead behind the seats and the rear of the car. Dynamat or similar products stop the low frequency noise best thru absorbing vibrations in the panels, closed cell foam absorbs the midrange and higher frequency sound waves. Put down the Dynamat first then the foam, the Frost King foam has a sticky side as well.
I focused a lot of time on the wheel wells as we all know the tires generate a lot of road noise up into the trunk area. Aside from the Dynamat and foam I also put acoustical insulation (Roxul insulation) in behind the sidewall speaker wells to fill those gaps.
Those speakers are just behind your head and there is a ton of open space that can echo sound up directly from the wheel well, that is now closed up. Odd that I noted on the right side they had already put some acoustical material in the space but none on the drivers side, almost like it got missed during assembly. Obviously GM recognized this area transmits sound from the wheel well up to the driver, too bad they wouldn't be a little more generous with the insulation they put in and apply it to both sides. I literally filled the cavity, bonus of better sound now from those speakers as well.
The noise elimination is significant. My wife who has no play in the game , no panacea effect, she couldn't believe the difference when I took her out yesterday. I would say the road noise from the rear is half of what it was and now very comfortable. No I haven't measured it with a DB meter but don't need to it was a substantial improvement no doubt. Stereo , you hear a lot more depth , more base. The doors and hatch a little tougher to close as the car is tighter so far as air movement. Well worth $250 and about 6 hrs of my time. Here some pics... I took the last pic before applying the Frost King over the Dynamat in the trunk. The wheel wells took by far the most time.