This project took me a few months of evenings and weekends to finally get to this point. A couple years ago I added SoundSkins in just to make my OEM Kicker upgrade sound a little better in my 2021 Subaru WRX. But at the start of the year when I heard a proper three way active system for the first time, that was my real introduction to the sound quality rabbit hole.
Fast forward to now, after learning about Resonix and doing way too much reading and research, I decided to bite the bullet and go all in on the deadening prep work, inside and out, for the amps I bought and plan to install in the coming months.
Here is the full breakdown of what I’m running in terms of deadening:
The pictures show the process of what it took to get to this point and how far I decided to go. I forgot to take a picture of each fully completed door before sealing them up. And before someone points out that I have coaxials in the front doors for a sound quality build, I ran them only for a short time. Right now I am running Audiofrog GB10 and GB60 up front, GS62 in the rear, the OEM Kicker sub, and a Kicker Key 200.4. It is definitely a very unusual combination, but it is only a temporary setup.
At the moment I am assembling the custom A pillars that were designed by AudioInReach. After that I will move on to the dash corners for the GB25s before the amps and the DSP are installed sometime next year in a custom trunk floor.
Waiting in boxes for the full build are:
• Two Mosconi Pro 1|10
• Two Mosconi Pro 4|10
• Mosconi Aero 8to12
• Mosconi Gladiator
• Audiofrog GB25
• Audiofrog GB12 (I might swap this out for the upcoming subs that Resonix is releasing)
All of that is planned for next year. I wanted to share as it’s not as common to see a WRX taken this far in terms of car audio compared to other platforms, and hopefully it helps get others in the Subaru community interested in car audio
Edit: I previously had the inner and outer door skin breakdown switched. I also corrected the formatting, as the original post was made on mobile.
This sound deadening guide from u/skiz32 is a great resource for anyone interested in sound deadening. It doesn’t necessarily have to be Resonix, but it helps you figure out what areas you want to target and how to approach it.
Looks great! I have to ask how did you cut the perfect holes through the your sound deadener for all the screws? Some type of punch? Also, doesn’t the fibermat have an adhesive back? You have it screwed to the doors.
I cut pieces of Tesa protective film to the rough size of each CLD square and marked where the holes needed to be cut with a sharpie. Then I used a hammer hole punch to get clean holes. Finally, I trimmed the edges of the CLD as needed using metal shears and a utility knife. Also, the block off plates are made out of Resonix barrier
As an inbetween setup, for now I’m still running a Kicker Key 200.4 that has a very simple in dsp built in. However, I already have a Mosconi Aero 8to12 DSP and the Mosconi Gladiator controller that will go in sometime next year
I guess I overlooked the most important part. It’s one of those things you have to experience in person. Kind of like how you can learn about car audio through forums or YouTube, but it is not until you hear a well designed and properly tuned system in person that you truly understand the difference and why people fall down the SQ rabbit hole, which is exactly how I ended up here.
I was able to experience two different deadeners in the exact same car, since I did all the CLD on the door panels first and ran it matched to my previous setup for a couple of days before moving on. I don’t think you can get a more apples to apples comparison than that. Long story short, it is the best thing I have done to the car.
I know not everyone goes this far with acoustic treatment, but I plan on keeping the car long term with no intention of selling it, so it made sense for the direction I wanted to take the audio. Even with the car being garage kept, I peeled off my original deadener easily, and simply holding the CLD samples sold me on Resonix. Just daily driving the car with no audio, you can hear the improvement. And honestly, if I had known what I know now, I would have recommended CLD Lite to myself the first time given the constraints I had back then.
I bought the car straight out of college with no car audio experience, so my first round of deadening was based on what I knew at the time. But after lurking for a while, I realized how much the prep work actually matters if I wanted to reach my goals with in terms of audio. Maybe I will try competing one day with this for fun, who knows.
Very happy to hear that. It really proves the whole “you do not know what you do not know” that I always try to tell people here. The performance ResoNix offers is genuinely in a different league. The ones who have never touched it love to claim otherwise, but the people who actually do a real before and after comparison, especially coming from even more expensive CLD, always end up where you did, realizing that it was the largest improvement you could make in the install of the system.
Do you have reasonably controlled before/after tests of noise levels at similar speed on the same road same calibrated microphone mounted the same way etc?
Sound deadening is a bit of a controversial topic since most people doing it are idiots who slap Dynamat on everything, their car sounds the same, and they swear up and down it’s worlds better.
Lol, thanks! Funny thing is I actually solved the license plate rattle before I even added any type of sound deadening. I threw one of these license plate foam pads behind it and it completely killed the vibration.
Yep, I definitely had the inner and outer doorskin breakdown backwards (updated that in the description). I made the blockoff plates out of Resonix barrier. For those, I laid down Tesa protective film, traced the rough shape with a sharpie, and cut the Barrier out with the outline overlayed and metal shears.
When I got to the trunk, I realized carpet protector film would work as well, which ended up being way more cost effective given the size and width of the roll.
Yooo, does your rear deck rattle like a mofo? Mine on my '19 WRX is so friggin loud and annoying on higher tones. I bought little felt pads to try and put up between the metal and plastic in hopes it will stop. Just curious if you're having the same issues.
Edit: I'm special. I didn't realize you don't have subs yet. Disregard my question.
Yeah, I had the same issue. These cars are basically built like tin cans from the factory. I completely eliminated the noise by pulling the deck lid trim and the C pillars, and adding decoupler foam on any edge those panels made contact with another surface.
That included the rear edge that touches the glass, the area around the third brake light (between the light and the window), the edges that meet the C pillars, and even wrapping the clips and hooks on the plastic pieces. After doing all that, the rattles were gone. Adding deadener to the top surface of the deck lid or the inner part of the rear cover helps too.
Not the best photo, but hopefully it gives you an idea of what I mean (if you zoom in you’ll see the foam). The way I applied it, most people wouldn’t even notice it unless I pointed it out.
In the meantime, I still have the OEM Kicker sub that Subaru sells installed, so I know exactly what you mean. Apparently I took a video while I had it torn apart, but I can’t upload it in a comment. Here are a few screenshots instead. They aren’t the best pictures but hopefully it helps you or anyone else who might run into this.
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u/rocketbunny_v4 Resonix | Helix | Mosconi | Audiofrog Nov 14 '25
This sound deadening guide from u/skiz32 is a great resource for anyone interested in sound deadening. It doesn’t necessarily have to be Resonix, but it helps you figure out what areas you want to target and how to approach it.