Sound proofing and Stock speaker, head unit replacement.

Started by Speedtactics, March 11, 2013, 09:28:04 PM

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   First let me start off by saying that if your considering sound proofing your Viper (2003-2010) and or replacing your stock speakers this is the place to start. If you like to hear the bottom line and want to know if this worked too bad, you'll have to read all my rambling to find that out.
   I started this as an idea last year when my stock 6 disc head unit in my 2006 Viper coupe decided to eat one of my CD's. As most of you know it's a shame we have such a nice car and such a terrible sound system. I could go on and on about it but if you drive a Viper and like to hear your tunes then you understand my complaints. Some of you out there subscribe to the motto "I don't need a stereo, I just put loud pipes on my car that's all I need to hear!" Well I don't entirely disagree with you however, there is a time and place for everything. If you know me, you know I enjoy the track days (When I'm there I turn the music off) and auto cross events. I also have to realize that my car is always pulling double duty. Car shows one day, track days the next weekend, off to Sedona AZ the next. So primarily I need a car that I can enjoy going to and from events. Driving three or four hours in a Viper is always an adventure, at freeways speeds we all know the dreaded "droning" sound. Don't get me wrong driving to Laguna Seca for five hours is fun! The track for two days was better, enough said.
   Before my head unit died, I had already exercised the Mopar ipod kit (Don't do it) and the Sirius satellite kit as well. Both of these kits can work depending on your model year and head unit. I experienced problems with the Mopar iPod kit, my dash went crazy with lights and the gauges did not function, so I returned it. Some people have had success with this kit, but the bottom line is that it was not designed for the Viper.
   With the stock head unit dead, I considered buying aftermarket units( Plans for a double din head unit are next). I had in my garage a Pioneer DVD head unit that was removed from my truck. This was a pretty good single din head unit back in 2004 (Dodge stock unit is 1.5 din) now of course it's dated. Since my cost was zero I decided to put this in and give it a try. I ordered a wire harness kit and a dash kit for 1.5 din down to single din down size. Total cost for these was a whooping $18.00, not bad for a test. (I know your thinking when is he going to get to the sound proofing, relax it's coming). Since this was pretty easy to pop in I had a my head unit installed in under 30 mins. No cutting no modifications! Everything worked with my new head unit, and the difference in sound was really noticeable. Even though this was an older head unit it still was quality and has many audio adjustments compared to the stock unit. Plus as an added benefit, this unit had an iPod direct connection and XM radio tuner so I had both options I wanted. The good news is anyone can do this and it's not hard, really it's not. Minimal investment in a $100-$200 head unit and install parts.
   What this did however was point out how bad the stock speakers are, and also how much noise is in the cabin when driving normally with the stereo off, I said driving NORMALLY!
   So I decided as my winter project I would jettison the stock speakers and in the process I would sound proof the car since it would be apart anyway right?
   I had done some sound proofing on my Mini and it was a big difference. So armed with that I ordered up some sound proofing material from Ebay. There are many different types of sound proofing. One of the more popular brands is Dynamat it's also one of the most expensive. For this job I actually used three different brands. Dynamat extreme, Accumat by Schosche and generic soundmat.
In this like many other things you buy, you get what you pay for. The Dynamat extreme and Accumat hyperflex extreme material are almost exactly the same. Prices vary so do your searching. I paid $150 for a box of Accumat hyperflex with eight sheets of 24"x27" on ebay.
   I didn't want to just install this stuff without some kind of measurement to know if what I did even made a measurable difference. So I ordered up a sound meter online as well. These are surprisingly cheap. Since this is not a crucial measurement I spent $20 on a meter on Ebay. As it turned out it's not half bad.
   My sounds test were conducted the following way.
My daughter Julia in the passenger seat holding the sound meeter up in-between the two seats in the center of the car, about where an adults ears would be. Next armed with pencil and paper we hit the freeway and proceeded to go "freeway" speeds in different gears and recorded the RPM, Speed and the sound DB levels. Since the meter does not do an average we held the meeter and just watched the levels until we had an idea of the middle measurement. ( I know not exactly scientific, but hey it worked ) We repeated the same gears and, speeds on the return trip on the freeway. For base line, The Viper is a 2006 with deleted crossover pipes and 2008 exhaust. Also for the guys out there that are in the know, K&N filters and BBK intake are also installed since the intake can make a lot of the noise you hear as well. The car is also riding on Sport Cup tires which you may know can be stiff and the tread or lack of can create issues on the grooved pavement as well.
   Now that we got that out of the way. This is what we came up with.
Gear   MPH   DB
4th gear   70 mph   81db
5th gear   70 mph   82 db
6th gear   70 mph   84 db

   Now it was time for the first modification. To start I removed the carpet and the plastic side covers from the rear deck and inside the back of the car. All of this comes out pretty easy. The first thing you notice once you have this removed is actually how thin the Viper "tub" or bottom of the car, is. Then you understand why the sound comes right through the floor. The sound proofing is self adhesive so all you have to do is pull the backing of and stick it down. I started by laying out the material and doing some tracing on cardboard to make templets for my sound proofing. Since this stuff is expensive you don't want to waist any of it. Save every scrap you have because you can use it someplace else. I used four of my sheets of 24"x27" to do the entire rear of the car and covered as much of the area as possible. We then ran some sound test again to see what if any results we had achieved. The results although noticeable and measurable were not enough to make a huge difference. What they did point out was how much sound was actually coming from the doors and side sills of the car.
   I Moved into phase two of my project. The doors and door speakers. Of all the things I removed from the car these have the most little screws and plastic pop parts. All of which can break and will if your car is older like mine. So be careful. If your only going to change out your stock speakers there is no need to remove your door panel. The speakers come off with three screws and the wire unplugs from the speaker. I removed my door panels but did not disconnect my door handle cable which is attached behind the door panel. No big deal since there is enough cable to leave it connected and do the job. I proceeded to sound proof the entire back side of my door panels. As much area as I can cover I did. This takes roughly one 24"x27" sheet.
   For my speakers I also got some foam speaker cones that go inside the door for added sound proofing, $6.00 for a pair. The speakers I got were a direct replacement for the stock 6.5". JL audio makes a 6.5" door speaker model C2-600X . these drop right into the stock holes and the stock grills fit right on. You could change these out in less than 20 minutes. I took the connector right off the old speakers and soldered it on to the new speaker so it clips in very easy, Cost $179.00 for speakers. (this and the head unit makes the biggest difference in the stereo)
   Next it was time to tackle the hard stuff, the sub and tweeters behind the seat! Most people will avoid this because of the fact that they have to remove the seats. In my experience you only need to remove the passenger seat to remove the plastic bulk head behind the seat that covers the sub woofer. It again is not hard but it's best to have two people for this job, the seat needs to be turned and tilted to get it out of the car and the plastic bulk head is just awkward to get out so having two people simplifies the process. I'm not going to go into removal details, just follow all the screws. If you have questions just email me.
Once the bulk head is out you get a look at the sub woofer box. Again this is pretty simple removal to take the box out of the car a few bolts and a wire.
   At this point I also removed the driver seat so I could put my sound proofing behind and under that area as well. While both seats were removed, I added sound proofing on both sides of the transmission tunnel (Between the seats). Also along side of both seats on the side of the door sills, both floors, under the sub box and behind both seats under the plastic bulkhead. All of this is under the carpet and can't be seen. While this is apart you should get a good look around at your car. I discovered a few things that had to be repaired while I had this stuff removed and the carpet pulled back. I will start a different thread for the problems and repairs with photos.
   The plastic bulkhead behind the seats houses two small tweeters the stock size is 2.75". I removed these and replaced them with the JL audio C2-350x 3" tweeters. These however as you imagine are slightly larger. So I used a piece of universal abs plastic to fabricate some brackets to up-size the speakers. This was actually pretty easy, the stock tweeters are held in to the bulkhead with 4 posts with screws in them. I simply cut a square from the abs larger than my replacement speakers. Then used a hole saw to cut an approximately 2.75" hole in the center. used a small 1/4" drill to drill holes for the 4 posts. screwed the plastic on to the post. then offset the new speaker on top and drilled holes to mount it. The wire connector on the old tweeters where removed and soldered on to the new tweeters. Then they simply clip in to the wire harness.
   Next it was time to tackle the subwoofer. This is one of the most problematic parts of the system. The basic problem is the sub is in a poor location and to add to that it's too small. I chose to use the stock sub enclosure. I first chose to use a JL audio 6.5" shallow mount sub. Let me tell you now. I tried two different JL audio subs and they both are too big for the stock enclosure. Do your self a favor benefit from my research and pain. Use the Kicker sub if your going to retain the stock sub box. After installing the kicker and testing it. It vibrated and distorted pretty bad. So I removed it and gutted the stock sub box, by removing the inner tube and plugging the hole on top of the sub box. Again I used the abs plastic to make a cover to fit on the sub box with a tracing I made out of cardboard. The plastic is easy to cut with a jig saw. I used black silicone to seal it on and also used small screws to be safe. I filled the sub box with polly fill, same stuff inside of pillows. Then put everything back together. The stock sub box is not great. It still distorts a bit, I think from the plastic construction I will most likely create my own and replace it. Note: since this install I pulled the sub back out and added some foam tape around the sub where is mounts to the sub box. This worked great. I also plugged the holes in the sub where the plastic guide mounts to the outside of the box. (the guide that holds the wire for the speaker). Any place air can escape from the woofer needs to be plugged up. Once this was done there was no more distortion. It now sounds fantastic.
   At this point with my modifications finished I proceeded to start the process of putting everything back together. be sure and check everything twice to be sure you don't mis any thing.
   Now it's time to test out what I did and hear the difference. First let me say the sound of the stereo is greatly improved. Of course this is hard to measure, but it's a huge improvement and for the low cost worth the investment.
   For the sound proofing it was time for a test drive to hear first hand what I did. You can notice straight away as you start driving the difference in the cabin. The outside road and engine/exhaust noise is knocked down. the car just sounds more solid. It also cured many of the small little creaks and squeaks from the plastic panels. I had a passenger comment "I can tell the sound is kinda dead in here."
   Here are the results of the sound test after sound proofing. They don't seem as dramatic a change as I expected, but the change in your ears is greater than the results below spell out. To give you an idea of db measurement going from 70db to 80db it's doubling the sound level. So basically I 1/2 the db. Not bad.

Gear   MPH   DB   Difference
4th gear   70 mph   77 db   -4 db
5th gear   70 mph   78 db   -4 db
6th gear   70 mph   81 db   -3 db

   The total parts cost and descriptions are below.
All of these parts can be found online. I like to use they are a great source of information and have pretty good prices, they carry most everything you would need. However they don't have any information on Vipers and installs so don't ask. They carry everything I purchased to finish my upgrades.

Parts   Cost   Total
XTC 5-1/4 foam muffs   $6.99   $6.99
Dynamat xtreme 10425 (sound proof)   $65   $65
Husmat (sound proof)   $123   $123
Accumat (sound proof)   $150   $150
JL audio C2-600x 6.5" speaker   $179   $179
JL audio C2-350x 3" Tweeter   $89   $89
Universal plastic panel   $9.99   $9.99
Kicker 10cvt654 6" shallow mount Sub Woofer   $84.95   $84.95
All parts   Grand total   $707.93   
   In conclusion, I would recommend doing these upgrades to your car. Some can be done fairly quickly like the door speakers, and sound proofing the rear hatch area. If you enjoy driving your Viper long distance and would like to get rid of some of the drone on the freeway this is a great inexpensive way to do it.
   I have include photos of most of the process and highlighted key areas of the install. If you have any questions feel free to contact me and I will help you if I can. Enjoy your ride!

Scosche Accumat

Plastic removal , don't forget the little screws here

Rear parts all removed

Partial sound proofing on rear deck

Making cardboard tracings to use for the accumat

Entire rear deck finished.

One of the replacement door speakers

Foam speaker cones added to the door

The sub woofer under the plastic bulkhead

The beginning of sound proofing in the front with seats removed

Soundmat installed behind the seat (Hard to see in black)

Sound proofing on trans tunnel and rear bulkhead behind seats

Sound proofing on passenger floor, transmission tunnel and along the side

Replacement tweeters for behind the seat

Making of ABS plastic rings to fit the new tweeters

Mounting ring attached to the underside of the plastic bulkhead

New tweeter mounted to the ABS and bulkhead

JL audio sub that does not fit , it just doesn't fit, you can see how far it sticks out

The sub box with guts removed

ABS cover used to close the port on the sub

The Kicker sub mounted in the car under the grill
Scott Hirko
2016 Viper GT with TA 2.0 package and APR carbon aero package.
2014 GTS track pack with TA 1.0 carbon aero package.


Excellent write up Scott!  Would you mind coming over and hooking me up.


Excellent write up Scott.
Took me 2 days to read it    >w   

What was the total weight added to the car?  for more viper pictures

Banzai Ben

Nice Hirk!
Trying to make it more like a Vette?  >w
2013 SRT Viper, Race Yellow
2003 Viper Comp Coupe, GTS Blue
2005 SRT-10 Ram, Yellow Fever
2018 Hellcat Challenger, Indigo Blue

PCH VIPER  for more viper pictures


Thanks guys, I appreciate you taking the time to read it. Lance I actually added about 30lbs to the car with the sound proofing. I would guess a few more pounds in magnets on the new speakers. The added weight helps me drive in the snow better. >v
Scott Hirko
2016 Viper GT with TA 2.0 package and APR carbon aero package.
2014 GTS track pack with TA 1.0 carbon aero package.


Quote from: NK BREKR on March 12, 2013, 11:01:32 PM
Excellent write up Scott!  Would you mind coming over and hooking me up.
Art, I can do it! $750 plus any supplies 😃
Scott Hirko
2016 Viper GT with TA 2.0 package and APR carbon aero package.
2014 GTS track pack with TA 1.0 carbon aero package.