Road Noise from rear cab vents..?

I was thinking of putting the egg crate side directly over the vents. Air should still be able to escape the cabin but this is very thick and would have to be compressed a bit.

IZO All Supply Convoluted 2" 12in W x 12in L Egg Crate Panels Acoustic Foam Sound Proof Wall Tiles, 6 Pack

https://www.amazon.com/gp/aw/d/B076JNCQ39/ref=ox_sc_act_image_1?smid=A2D4URBA75P65Q&psc=1

Or this hushmat it's thin and has adhesive and should allow air to escape around it.

$30 HushMat 10150 Multi Use Kit - (4) 12" x 11" Black Ultra Sheets - 3.7 Square Feet

https://www.amazon.com/gp/aw/d/B001VKVBCY/ref=ox_sc_saved_image_1?smid=A2QAUX85P3FRST&psc=1

 

Yep, looking back on this old thread I will do it like go2cnavy did.

 

Route I am going after advice for another post on this thread. MLV over the vents and seal perimeter of vents.

For those curious, I used Sound deadening strips then second skin luxury pro mass loaded vinyl. This MLV is 3/8” thick and comes with the foam attached saving a step in the process. This is the most material you could possibly fit behind the plastics. I now have to slam the seat to latch but that’s ok with me.

So far I am very happy with the results and expect to notice a difference. Will be installing a Dometic 50 fridge behind drivers seat shortly so will not run with seat or plastics and need to reduce sound transmission.

 

Derek, You have no air flow restrictions after covering the vents with MLV?
I was thinking about doing it this way also since it seems like there would be enough channels open for air.

I just ordered egg crate foam on Tuesday for the vent area and will get it Friday, I decided against the MLV as it's too expensive but can always get some MLV. Please let me know if you have any air restrictions.
Thanks

 

I will report back once mine is all buttoned you, but I went this direction due to feedback on post #47 which seems to confirm it works just fine. I would say there does seem to be plenty air pockets around the vents even after laying over MLV. With the corrugation and the center bar, there is a lot of air space left.

If I had to do it again I would have not installed that sound deadening. I don’t think it’s going to do much at all. The whole back wall is corrugated which inherently is stronger than a flat panel so there shouldn’t be much vibrations. The material is cheap and it’s fairly easy to allow and I will use it for the door speakers but don’t think it’s needed for the back wall.

 

I was thinking that the sound deadening tiles would probably be ineffective and canceled my order but hopefully the acoustical foam should work. I remember reading post #47 but I didn't want to spend a lot of $$$ on a sheet of MLV. But then if it works it's money well spent. I think I found the stuff you got.

https://www.secondskinaudio.com/sound-blocking/luxury-liner-pro

 

I ended up breaking 7 of those pink clips, does anyone have any experience with these as replacements?

$12 Rexka 20pcs Upper Quarter Trim Lower Overhead Console Clip Red Nylon 90467-09240 for Toyota Lexus Tacoma Camry C-HR Prius

https://www.amazon.com/gp/aw/d/B07R1QTSQ1/ref=ox_sc_saved_image_6?smid=A3T7YNU723BG3V&psc=1

Edit 12/31/19: Yes they are the same clips.

 

Hate to ask this now, but can you get a BEFORE decibel reading either with an actual SPL meter or using an app on your phone, then repeat the process for an AFTER reading as well so we can determine with evidence that the road noise has decreased by X amount of dB's? The same road would have to be used, at the same speed (e.g. highway section at cruise control) to get an accurate comparison.

It is more than just anecdotal evidence that road noise decreases slightly when RECIRC mode is ON, but having good before and after would be awesome.

I just worry that the restricted, outward airflow will affect the deployment of the airbags in a severe crash.

 

Total noob to this, but could you use cotton/denim insulation instead? In theory it would allow air movement and absorb noise.

 

More anecdotal evidence, my project is done. Whole back wall is MLV in the thickest you can squeeze in. I haven’t noticed any difference with material over vents in regards to defrost time, sound or pressure of doors shutting.

I went this route as I removed rear seat behind drivers seat to install a fridge. I feel my sound level in cab is at least back to the level of having the seat installed. You wouldn’t believe how loud it was without seats installed. Like someone else mentioned it’s literally like you have a window open.

I will say for anyone thinking about going with 3/8 of material behind seats and plastics it’s tough but can be done. The tightest fit is the corner plastics.

 

So does this means that the MLV was ineffective?. Also were you able to reattach the stock sound deadening sheet or did you leave it off due to the thickness restrictions?
Thanks.

 

I meant it was effective because if you remove the rear seats it will be as noisy as having a window open and now it’s at least back to normal

I left the stock material off. No way it’s going to fit

 

I just ordered a sheet of the MLV. If anyone else is interested here is a 10% off coupon making it $63.00 shipped.
SS4THEWIN10 I think it's good till the end of the year.

https://www.secondskinaudio.com/sound-blocking/luxury-liner-pro

So far this is what I got done this weekend. Probably won't get the MLV till next year.

 

Here I how I addressed the issue. I took the sou d deadener from Amazon which works well and is 60 bucks vs the dyna mat I use in my Camaro at 170. I lined the floor and back wall . I plan to use my truck alot with the seats down and am installing the back molle panel. So the vents need to be addressed. What I did was take the sound curtain that was back there and cut it up to create a dual layer that could be held by the dyna mat. This made all the difference and still allows for air flow. I also used the deadener to make the 2 pieces become 1 and add an extra layer of deadening right where the sound come thru.

 

Question for those that have removed the back plastic panel in the access cab .... I'm considering putting in the "egg crate foam" only in the horizontal area and cover the vents. Must I remove the remove rear panel to install the foam? Or - can I pull the top back enough to slide the foam in ??? Thanks

 

Refer to this thread--

https://www.tacomaworld.com/threads/removing-rear-seats-and-back-panel-from-2016-access-cab.411587/

It would probably be more difficult trying to just pull the top back rather than remove the entire panel. You can try it through but you will probably find it easier to do the job with the panel completely removed, that way you can silicone caulk around both of the vents.

The link above is an excellent write up for doing this job.

Look at the bottom pic for the location of all the pink clips, some of them will break as they are not intended to be reused.

You can get more here though--

$12 Rexka 20pcs Upper Quarter Trim Lower Overhead Console Clip Red Nylon 90467-09240 for Toyota Lexus Tacoma Camry C-HR Prius

https://www.amazon.com/gp/aw/d/B07R1QTSQ1/ref=ox_sc_saved_image_6?smid=A3T7YNU723BG3V&psc=1

 

Pull it, really easy to do.

 

All took out the back seats picked up the carpet and put Matt 66 sound deadening material over all of it from the back wall to the front seats, also done my doors huge difference. The vents are sealed and it has no noticeable effect other than being incredibly quiet. Now this is on a 2020 TRD off road which has more sound deadening and thicker Windows supposedly

 

Just thinking out loud here. There may be an issue venting large amounts of air extremely quickly if the air bag system is triggered, and the exhaust vents have been compromised. Just a few years back there were only 2 bags...drivers wheel, and front passenger. Now there are up to 8. drivers wheel, front passenger, 2 under dash, 2 on out board front seat backs, and 2 side curtains. That is a lot of air to vacate in just milliseconds. Thoughts?

 

Yup you never want to seal the vents. If they are sealed and you are lucky it’ll rupture your eardrums and blow out a window or seal. Unlucky they don’t fully deploy and aren’t strong enough to help. Just looking through this thread and seeing how covered some folks have them would make me nervous if only because I wouldn’t want to be deaf after a small accident.