Subaru Outback Forums banner

1 - 20 of 41 Posts

Registered
2011 Outback 2.5 Limited
Joined
140 Posts
Discussion Starter #1
Lately I have been noticing the road noise intruding into the cabin on my 2011Outback. I was toying with adding some soundproofing materials to help eliminate some of the noise. I have 2 questions:

1) What are my options for soundproofing materials? I know of FatMat, which I understand is expensive. What else is out there?

2) Where should I install this to get the best results? I dont plan to put this stuff everywhere, just selected locations that will make the most difference.
 

Registered
2011 Outback Limited 2.5i/2018 Crosstrek limited
Joined
4,512 Posts
Lately I have been noticing the road noise intruding into the cabin on my 2011Outback. I was toying with adding some soundproofing materials to help eliminate some of the noise. I have 2 questions:

1) What are my options for soundproofing materials? I know of FatMat, which I understand is expensive. What else is out there?

2) Where should I install this to get the best results? I dont plan to put this stuff everywhere, just selected locations that will make the most difference.

Somewhere on this model forum there is a thread with pics from someone who put dynamat in their car. I know that combatmedic put damplifier pro in his...maybe PM him to find out what's involved.
 

Registered
"Tank" - 2011 OB 3.6R w/ Nav & Moonroof in Graphite Grey
Joined
872 Posts
I am half way done with soundproofing. So far, I can tell you that doing the rear hatchdoor made the biggest difference (no idea why). I have covered the entire rear cargo area and sides, and front passenger door with Dynamat Extreme and the rear hatch door I also added the thickest dynaliner as well. I will finish the rest of the doors with Dynamat Exrreme, and after the speakers go in, will replace the plastic with dynaliner, and do the floor with dynamat extreme and dynapad, and headliner with dynamat extreme and dynaliner as well at somepoint. You can get very good deals on Dynamat online- best price I found was at www.streetsideauto.com and if you google them sometime you will find additional coupons. (finishing this is a long term project, as its rather costly and time consuming, but overall I think its worth it for the long run. I would buy the super-mega shop pack which is 75 sq. feet to start. That covered the entire cargo area and hatch door, and one passenger door, and i have one full sheet left which I am saving in case I need it for the subwoofer install. I hope one more pack will finish me up, but I dont know yet. if you search on here you will find more threads with pics.


 

Registered
2010 outback. base 2.5
Joined
1,970 Posts
Comming from the Honda stable I thought I bought lexus as far as lack of road noise. IMO it's not worth the money, that said, I have noticed the Contis tend to be a little louder as they wear down. I think the car is very quiet without any other soundprofing measures.
 

Registered
"Tank" - 2011 OB 3.6R w/ Nav & Moonroof in Graphite Grey
Joined
872 Posts
I don't want a car that excels in only one area so I am fine spending a few bucks here and there to help fill in the gaps on the OB to suit my requirements. Small price to pay for such a versatile high quality car that is great off road as well as on, plus- it's fun to mod! :)
 

Registered
2011 Outback Limited 2.5i/2018 Crosstrek limited
Joined
4,512 Posts
I am half way done with soundproofing. So far, I can tell you that doing the rear hatchdoor made the biggest difference (no idea why). I have covered the entire rear cargo area and sides, and front passenger door with Dynamat Extreme and the rear hatch door I also added the thickest dynaliner as well. I will finish the rest of the doors with Dynamat Exrreme, and after the speakers go in, will replace the plastic with dynaliner, and do the floor with dynamat extreme and dynapad, and headliner with dynamat extreme and dynaliner as well at somepoint.
Quick question for you. After putting that stuff in, how did the liners etc fit back into place? Any fit problems due to the space that it takes up?
 

Registered
"Tank" - 2011 OB 3.6R w/ Nav & Moonroof in Graphite Grey
Joined
872 Posts
Everything fit back fine so far except one spot where I need to trim in the hatch because I got lazy. But the cargo area and rest of the back and under the back seat caused zero fit issues. No issues with door either.
 

Registered
2013 Outback 3.6 Limited
Joined
213 Posts
I am half way done with soundproofing. So far, I can tell you that doing the rear hatchdoor made the biggest difference (no idea why). I have covered the entire rear cargo area and sides, and front passenger door with Dynamat Extreme and the rear hatch door I also added the thickest dynaliner as well. I will finish the rest of the doors with Dynamat Exrreme, and after the speakers go in, will replace the plastic with dynaliner, and do the floor with dynamat extreme and dynapad, and headliner with dynamat extreme and dynaliner as well at somepoint. You can get very good deals on Dynamat online- best price I found was at www.streetsideauto.com and if you google them sometime you will find additional coupons. (finishing this is a long term project, as its rather costly and time consuming, but overall I think its worth it for the long run. I would buy the super-mega shop pack which is 75 sq. feet to start. That covered the entire cargo area and hatch door, and one passenger door, and i have one full sheet left which I am saving in case I need it for the subwoofer install. I hope one more pack will finish me up, but I dont know yet. if you search on here you will find more threads with pics.


How did you install the Dynamat over the stock insulation layer at the bottom of spare well? It does not look like it will bond properly unless you strip it out first. I had some leftovers from the doors and did a few pieces and noticed the stock spray-on insulation at the bottom of well.

Thinking about ordering a whole kit to do the cargo area. Lots of bare metal back there and easy to access.
 

Registered
2011 outback,2.5 Ruby Red
Joined
209 Posts
Will the 1 kit they sell (9) pcs. 18"x32" be enough to do about 1/2 the car? Rear Hatch Door and back hatch floor and sides ?
 

Registered
Joined
28 Posts
Where to begin...

Some of the things I say may be controversial, but I have verified them with decibel meters and RTA analysis. I have gutted my entire car twice in the pursuit of sound reduction for audio purposes and spent probably 80-120 hours on my car alone. I have also gutted someone else's car for the same purpose.

First of all, sound deadeners like Dynamat, Second Skin, and the knockoffs are not meant to reduce outside noise. This is good because they don't. What they do is stop metal from resonating and causing noise that way. If you have large drivers in your doors or a sub in your trunk, deadening mats will keep the metal from vibrating. They don't do squat to stop tire noise or outside noise from entering the car.

Closed cell foam: by itself it does next to nothing to stop outside noise or road noise. Road noise usually runs in the 80 Hz - 250 Hz range. Closed cell foam is completely ineffective in this range. Closed cell foam only starts to be effective about 3k Hz.

Acoustic insulation: this stuff is the real deal! It's what car manufacturers use under your carpets anyway. Bonded Logic makes great cotton insulation out of recycled blue jeans. It's cheap, light, and easy to work with. You stuff the 4" batting in any empty crevices that don't get wet so fill up the entire gap between the outer panels and the inner trim. They also make a 1/2" foil backed sheet that goes under carpets or headliners. This is great stuff! Use it liberally.

If you really want to stop all outside noise you need mass. That's the only thing which will be effective against low wavelengths. The two most common materials are lead and mass-loaded vinyl. Dynamat Extremeliner is the only commercial product I know that has lead sheeting sandwiched in it, but it is ridiculously expensive. It's much cheaper and arguably more effective to make your own mass-loaded vinyl sandwich.

This is how I did it: You use a deadener like Dynamat, Second Skin, etc., on your outer panels. This will stop any resonating (don't bother with structural metal, it's so thick it won't resonate anyway). Second, you glue a robust closed cell foam layer on top of that. I use Ensolite, but there are dozens of foams out there. The foam doesn't do anything by itself, but it makes a great substrate for step three which is a mass loaded vinyl layer. You glue the mass loaded vinyl on top of the foam. The theory is that the sound waves pass through the foam but are reflected by the vinyl until they dissipate in the sounding rejecting sandwich that you've created. Finally, you add the Bonded Logic on top of that. Voila! You will now see a huge reduction in sound!

Naturally most people won't go to the lengths I did. If you only do one step, get the Bonded Logic acoustic insulation. It's the cheapest, and easiest to install and also the most effective at noise reduction for the money.
 

Registered
Joined
28 Posts
This is a Honda Prelude not an OB, but the procedures are the same...

Step one: coat the outer panel with a deadener. I used a paintable elastomeric compound. This is a door by the way.



Step two: use a good adhesive to glue your 1/2" Ensolite or other closed cell foam on top of the deadened layer (here's a hint: buy scrap remnants of foam it's really cheap that way)



Step three: Use a good adhesive to glue your mass-loaded vinyl on top of the closed cell foam. I used a product called Audimute. This is a finished door:



This is a finished floorboard after the same procedure:


Once you have done that, stuff the insulation anywhere you can:


All over the trunk:


Behind trim panels (this not only blocks noise but stops trim panels from squeaking and rattling)





And finally, yes, it all does go back together again, but it will be a tight fit
 

Registered
Tungsten 2017 2.5 Limited w Eyesight SOLD!
Joined
1,043 Posts
^^^ Nice job albeit a lot of work!! I used Dynamat and found it to be very useful in quieting down the car. It didn't stop all the noise but helped a lot in reducing the odd vibration in the panels and made the doors close with more authority. If I wanted a dead quiet car I would get a Rolls Royce...:D As my finances aren't such I can afford one, I'll take what I can.
 

Registered
Joined
28 Posts
Yes, mats like Dynamat are great for rattles, but they don't block sound from entering the car. They do help, however, because sometimes the body panels can resonate, depending on the type of surface you're driving on. Mats will stop the resonating, but they don't block the sound of the tires on the road which is actually quite high judging by my Outback. Those Contis are LOUD! To stop that noise, you need to go hardcore.

I can make almost any car as quiet as a Roller. The two problem areas are door seals and glass. That's where you get the most outside noise anyway. Luxury cars use dual pane glass. That's the one area where I can't make any improvement on an ordinary car. They also use triple door seals. While I can do something just as effective, it won't look stock (and actually kinda ugly).
 

Registered
2010 outback. base 2.5
Joined
1,970 Posts
Not to be disrespectful of everybody's hard work, but these cars at least my marshmallow riding 10 is as quiet as your going to get for a $20xxx car/SUV. If you want total isolation I guess you should of reached deeper in the pocket for a Lexus. Drive the current Forester or the new Impreza and you will no what noise is. I have found with my previous Honda's that tires and some undercoating will make a small difference but it is what it is. Although I have not tried put the effort in some of other people have with extensive soundproofing methods
 

Registered
Tungsten 2017 2.5 Limited w Eyesight SOLD!
Joined
1,043 Posts
Those Conti tires are on the way out anyway and a set of Michelins are in the future. That will improve handling sound levels and vibration too. I just put new brake pads on my car and found out that just one wheel has 7 oz of weights on one side and 4 on the other..:gasp: WTF is up about that?? Those tires suck the wind out of life IMHO..:mad:
 

Registered
2013 OB 3.6R SAP
Joined
203 Posts
I for one am very appreciative of the effort others have put in to document their work. Like some of the folk here, I find the OB a bit too noisy for my tastes, and I'll likely undertake a project like this.

I don't consider it a waste of time at all, and applaud anybody who tries to intelligently tailor their personal vehicle (regardless of how expensive - or cheap - it is) to their own tastes.
 

Registered
Joined
28 Posts
Not to be disrespectful of everybody's hard work, but these cars at least my marshmallow riding 10 is as quiet as your going to get for a $20xxx car/SUV. If you want total isolation I guess you should of reached deeper in the pocket for a Lexus. Drive the current Forester or the new Impreza and you will no what noise is. I have found with my previous Honda's that tires and some undercoating will make a small difference but it is what it is. Although I have not tried put the effort in some of other people have with extensive soundproofing methods
A Lexus doesn't have nearly the utility of an Outback. As long as you do the work yourself, it doesn't cost much to get Lexus quality noise isolation from an Outback. Actually, you can get a lot quieter than a Lexus. An Outback + $1,000 in materials is an excellent alternative to a luxury vehicle. You could get excellent results just by adding lots of Bonded Logic Ultratouch.
 

Registered
2017 Outback, 14 Jeep Grand Cherokee, 07 BMW E-93
Joined
604 Posts
Having owned Lexus and many BMWs which I still own I can say that the 3.6L 13 Outback is extremely quiet. I have been surprised how quiet this car is. Very impressed. Also the dual door seals help a good bit.
I see no point in doing any sound deadening efforts but then again my perspective is different from what yours might be...
 

Registered
Joined
28 Posts
Having owned Lexus and many BMWs which I still own I can say that the 3.6L 13 Outback is extremely quiet. I have been surprised how quiet this car is. Very impressed. Also the dual door seals help a good bit.
I see no point in doing any sound deadening efforts but then again my perspective is different from what yours might be...
I agree that the OB is a respectably quiet car. The one problem are those Contis. They HOWL on concrete above 65 MPH. I've had horribly cupped tires that weren't as loud as the Contis. They aren't as bad on asphalt, but **** they make a racket on concrete! The easiest solution is just to buy quieter tires, but it would be cheaper to stuff some insulation inside the cabin above the wheels wells.
 
1 - 20 of 41 Posts
Top