Go Back  ClubLexus - Lexus Forum Discussion > Lexus Model Forums > NX Models (2015-present)
DIY - Reduce Rear Hatch Audio (Sub Woofer-Generated) Vibrations >

DIY - Reduce Rear Hatch Audio (Sub Woofer-Generated) Vibrations

Notices
NX Models (2015-present)

DIY - Reduce Rear Hatch Audio (Sub Woofer-Generated) Vibrations

 
Old 12-19-15, 12:58 PM
  #16  
NickTee
Lexus Test Driver
 
Join Date: Apr 2015
Location: Texas
Posts: 1,085
Likes: 0
Recieved 4 Likes on 4 Posts
Default

Denim insulation is treated with boron-based fire retardant.
NickTee is offline  
Old 12-19-15, 01:16 PM
  #17  
Formula271
Rookie
 
Join Date: Mar 2012
Location: MI
Posts: 75
Likes: 0
Recieved 1 Like on 1 Post
Default

Originally Posted by NickTee View Post
Denim insulation is treated with boron-based fire retardant.
So is all the other "denim" shoddy pad used on various interior bits....you won't find any installed next to seatbelt pretensioners
Formula271 is offline  
Old 12-19-15, 01:30 PM
  #18  
corradoMR2
The pursuit of F
Thread Starter
 
corradoMR2's Avatar
 
Join Date: Jul 2006
Location: Toronto, Canada
Posts: 8,024
Recieved 147 Likes on 116 Posts
Default

^^^ These are valid points and challenging a DIY, a post, etc is welcome when backed by facts since it provides other credible information for people to consider before engaging in the DIY.

As a note, what you see in the B-pillar pic is not Great Stuff as it would seize the seat belt pretensioner but a soft non-rigid fire-retardant denim insulation and fire-retardant Eco Foam Cork underlay which neither of them are interfering with the proper functioning of the seat belt. However, moving forward, let's stay on topic to this thread on the sub DIY. Thanks guys.
corradoMR2 is offline  
Old 12-20-15, 11:35 AM
  #19  
illa
Driver School Candidate
 
Join Date: Sep 2015
Location: Illinois
Posts: 18
Likes: 0
Recieved 0 Likes on 0 Posts
Default

Hi guys,
I would like to share my experience on this matter and hopefully someone will find it helpful.
I drive a nx200t with what they call premium amplified 10 speakers sound system.
What I didn't like right away was the flat washed out sound with rattle in the front doors and it was a complete disaster in the tailgate back door where they placed the sub.
There were multiple threads on this forum related to the same sound issues without too much help, at least for me. I was trying to find out the right steps to take, to make the sound not perfect but at least reasonable.
I gathered a lot of info from Russian Lexus forums, since I can read it, there are a lot of enthusiasts out there and very professional shops fixing sound in cars.

So, #1 is SOUND PROOFING, UNFORTUNATELY buying premium brands doesn't mean a crap anymore, they are cheating everywhere.
LEXUS IS EMPTY INSIDE, METAL all around, with little insulation on plastic parts, see pics of the door.
Proper sound deadening will reduce road noise, eliminate rattling, and improve sound picture even with stock speakers.
I am pretty handy with my cars, but I was still skeptical to do it myself, so I start looking for a good shop with decent prices here in Chicago.
To my surprise they are almost non exist or very expensive, as I understand the most capable are in the California LA area.
I went with Showtime shop, there were some glitches as well but the owner took care of me pretty well.

#2 which materials to be used, Dynamat or analog, they all use Stinger now for a more affordable price and 1/8~1/4" foamy material not absorbing moisture between the panels to get rid off squeaking noise. I do not suggest any spray foam, or fiberglass insulation in your car.

#3 which speakers to replace and brand to use. I was debating between Focals and Hertz, after spending sometime in a local store called ABT with very good stand in mobile department. I ended up with Focal Flex line 165F two way component system for Front only.

#4 Showtime, I arrived in the morning for all day project. They removed all the panels from all five doors, and speakers as well. Then they Applied sound materials as I described above. 6.5" Speakers in front doors are slightly better than in rear doors so they swap them out, Installed new Focals in the front doors and new tweeters in the front panel. The center channel stayed the same. I Decided to leave the original sub for now and test it after all work is done. There is not too many options with stock sub, I found Kicker model which will fit there but left it for another time.

#5 Finally, I achieved my goal. The sound has improved drastically, and I enjoy it a lot. Focals are amazing even with stock amp. No more rattles, even in back door where the sub is. The Sub itself sounds much better but I still didn't give up the Kicker option.

#6 Budget, in my opinion this is best you can get for 1k project keeping the stock amp. Anything else will be a completely different ballgame and require sound processor, new amp, etc.... at least 3~5k more.













illa is offline  
Old 12-20-15, 06:19 PM
  #20  
corradoMR2
The pursuit of F
Thread Starter
 
corradoMR2's Avatar
 
Join Date: Jul 2006
Location: Toronto, Canada
Posts: 8,024
Recieved 147 Likes on 116 Posts
Default

illa, thanks for your post and pics to further help forum members interested in this topic.

As pinhead mentioned, do you have any other pics, in particular the rear hatch which would best relate to this thread?
corradoMR2 is offline  
Old 12-21-15, 05:40 AM
  #21  
illa
Driver School Candidate
 
Join Date: Sep 2015
Location: Illinois
Posts: 18
Likes: 0
Recieved 0 Likes on 0 Posts
Default

Might have a few more to share, will upload later.

Originally Posted by corradoMR2 View Post
illa, thanks for your post and pics to further help forum members interested in this topic.

As pinhead mentioned, do you have any other pics, in particular the rear hatch which would best relate to this thread?
illa is offline  
Old 12-21-15, 08:10 PM
  #22  
NickTee
Lexus Test Driver
 
Join Date: Apr 2015
Location: Texas
Posts: 1,085
Likes: 0
Recieved 4 Likes on 4 Posts
Default

I posted this in another thread, perhaps it will educate illa:


My estimates were based on a full liner, though the rear liners on some cars have the carpet liner that are already designed for sound absorbency. Obviously the estimates will change based on the available size that you can spray on the liner, but you should still try to achieve around .5 lb/sq ft. at a minimum. This is because you're trying to block low frequency soundwaves, which requires a thicker, denser material.

I believe you misinterpreted what I said. Raammat BXT II is a CLD, constraint layer damper, and should be applied directly onto metal surfaces. Not only that, you should also be using a wood or plastic roller to firmly press it onto the surface. It's not something that should simply be stuck on or barely pressed down, you really want it on there so that it can act as a proper constraint layer. This is really only needed on panels like the door skin, roof, trunk lid and floor, and other thin panels. You can put it on the floor if you wish, but the floor pan is usually reinforced and does not vibrate easily on newer cars. Do the knock test, if you get a fairly firm thud then it's fairly pointless to smack more CLD tiles on the surface.

The sole purpose of using CCF(closed-cell foam) in a car is to act as a decoupler. CCF is a poor sound absorber due to the closed cell design (lower porosity yields lower flow resistivity, which yields poor absorbance), open cell foam is more effective due to higher porosity, but it holds water. That's why open-cell foam is not usually used in cars, since you don't want it trapping moisture, and that's why CCF is only used for decoupling (because it is a poor absorber).

Even if CCF was a good noise absorber, because it has low flow resistivity at 1/4" it would only be absorbing frequencies of around 13.5kHz. Road noise is around 200-4000 Hz, which would require a minimum 1.5" of foam with a high flow resistivity of around 10,000 rayls/m, to achieve near 100% absorbance (7% of the wavelength at STP in air yields almost 100% frequency absorbancy, because the speed of sound slows down in porous materials and the actual wavelength within the porous material is approximately 22-25%) of peak noises around 600 Hz.

So you can see that simply throwing in greater layers of foam, especially closed cell foam, is not going to be particularly effective unless you wish to build a layer of two inch thick foam. This is why we use mass loaded vinyl (MLV) as a barrier, not an absorber, and use CCF to decouple the mass loaded vinyl and have it act as a limp mass barrier. Due to its high density, 1-2 lbs per sq ft, it is very effective for blocking lower frequency noises.

So to summarize: use CLD tiles on the bare metal, place CCF over the entire surface to decouple it, then lay MLV over the entire surface with zero gaps. Any gaps you leave are gaps where sound waves can enter.

If you wish to learn more, look up flow resitivity, porosity, the Allard-Champoux model, angular frequency, real part of the complex wave length.
NickTee is offline  
Old 12-16-17, 07:08 AM
  #23  
JLEXNX
Driver School Candidate
 
Join Date: Oct 2017
Location: Massachusetts
Posts: 24
Likes: 0
Recieved 4 Likes on 4 Posts
Default

First thanks for all the insight, my question is Can I put polyfill in the tailgate through the panel?
JLEXNX is offline  
Old 01-03-19, 12:43 PM
  #24  
jasonvideo
Driver School Candidate
 
Join Date: Jan 2019
Location: NC
Posts: 2
Likes: 0
Recieved 0 Likes on 0 Posts
Unhappy How-to?

Is there a link to instructions as to how to actually remove the hatch panel? I want to get in there to add some dynamat.

Thanks,

Jason (newbie)
jasonvideo is offline  
Old 01-05-19, 12:09 PM
  #25  
skyshadow
Pole Position
 
Join Date: Mar 2015
Location: America
Posts: 382
Recieved 36 Likes on 24 Posts
Default

Something had to have changed between the first gen NX and the second gen. My first gen 2016 would rattle very loudly in the rear hatch when music was turned up. But, my 2018 NX has not rattle sounds under the same conditions.
skyshadow is offline  
Old 01-05-19, 03:13 PM
  #26  
ross7777
Pole Position
 
ross7777's Avatar
 
Join Date: Nov 2018
Location: MN
Posts: 280
Likes: 0
Recieved 26 Likes on 23 Posts
Default

Originally Posted by skyshadow View Post
Something had to have changed between the first gen NX and the second gen. My first gen 2016 would rattle very loudly in the rear hatch when music was turned up. But, my 2018 NX has not rattle sounds under the same conditions.
Same here. No issues with my 2019. They likely added more sound deadening material.
ross7777 is offline  
Old 01-05-19, 06:19 PM
  #27  
jasonvideo
Driver School Candidate
 
Join Date: Jan 2019
Location: NC
Posts: 2
Likes: 0
Recieved 0 Likes on 0 Posts
Angry

Originally Posted by ross7777 View Post


Same here. No issues with my 2019. They likely added more sound deadening material.
Exactly why I need help opening the hatch. (2015)..Thanks.
jasonvideo is offline  
Old 01-08-19, 12:11 PM
  #28  
slypx
Driver
 
Join Date: Sep 2017
Location: Quebec
Posts: 112
Recieved 21 Likes on 13 Posts
Default

Originally Posted by skyshadow View Post
Something had to have changed between the first gen NX and the second gen. My first gen 2016 would rattle very loudly in the rear hatch when music was turned up. But, my 2018 NX has not rattle sounds under the same conditions.
I have a 2018 (March) and it sure came with a lot of vibration... Brought it back to the dealership and they fix 95% of the issue by isolating the back door at no charge. Then, they add some "spongious" tape behind the licence frame. Not enough for me, I added some more last week as they only did the upper part, I did the bottom part. I would say that 99 % of the rattle is now gone ... Don't have pictures of the back door as it was done within the dealership "back door" but here are some of the licence frame after I added some more last week ...





slypx is offline  
Old 01-09-19, 03:11 AM
  #29  
nigel821
Pole Position
 
nigel821's Avatar
 
Join Date: Jan 2017
Location: Virginia
Posts: 223
Recieved 17 Likes on 15 Posts
Arrow

Originally Posted by illa View Post
Hi guys,
I would like to share my experience on this matter and hopefully someone will find it helpful.
I drive a nx200t with what they call premium amplified 10 speakers sound system.
What I didn't like right away was the flat washed out sound with rattle in the front doors and it was a complete disaster in the tailgate back door where they placed the sub.
There were multiple threads on this forum related to the same sound issues without too much help, at least for me. I was trying to find out the right steps to take, to make the sound not perfect but at least reasonable.
I gathered a lot of info from Russian Lexus forums, since I can read it, there are a lot of enthusiasts out there and very professional shops fixing sound in cars.

So, #1 is SOUND PROOFING, UNFORTUNATELY buying premium brands doesn't mean a crap anymore, they are cheating everywhere.
LEXUS IS EMPTY INSIDE, METAL all around, with little insulation on plastic parts, see pics of the door.
Proper sound deadening will reduce road noise, eliminate rattling, and improve sound picture even with stock speakers.
I am pretty handy with my cars, but I was still skeptical to do it myself, so I start looking for a good shop with decent prices here in Chicago.
To my surprise they are almost non exist or very expensive, as I understand the most capable are in the California LA area.
I went with Showtime shop, there were some glitches as well but the owner took care of me pretty well.

#2 which materials to be used, Dynamat or analog, they all use Stinger now for a more affordable price and 1/8~1/4" foamy material not absorbing moisture between the panels to get rid off squeaking noise. I do not suggest any spray foam, or fiberglass insulation in your car.

#3 which speakers to replace and brand to use. I was debating between Focals and Hertz, after spending sometime in a local store called ABT with very good stand in mobile department. I ended up with Focal Flex line 165F two way component system for Front only.

#4 Showtime, I arrived in the morning for all day project. They removed all the panels from all five doors, and speakers as well. Then they Applied sound materials as I described above. 6.5" Speakers in front doors are slightly better than in rear doors so they swap them out, Installed new Focals in the front doors and new tweeters in the front panel. The center channel stayed the same. I Decided to leave the original sub for now and test it after all work is done. There is not too many options with stock sub, I found Kicker model which will fit there but left it for another time.

#5 Finally, I achieved my goal. The sound has improved drastically, and I enjoy it a lot. Focals are amazing even with stock amp. No more rattles, even in back door where the sub is. The Sub itself sounds much better but I still didn't give up the Kicker option.

#6 Budget, in my opinion this is best you can get for 1k project keeping the stock amp. Anything else will be a completely different ballgame and require sound processor, new amp, etc.... at least 3~5k more.














Excellent information! I am going to be doing pretty much the same to insulate door panels and tailgate. I like that they covered the holes... most people skip this part and it still has that hollow sound even adding sound dampening material to the door/inside..etc.

-Nigel
nigel821 is offline  
 


Thread Tools
Search this Thread
Quick Reply: DIY - Reduce Rear Hatch Audio (Sub Woofer-Generated) Vibrations


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: