what would be the best places to apply sound deadening on the XJ? to make it S class quiet

• doors;
• floor and wheel arches;
• firewall;
• trunk and trunk lid;
• ceiling;
• hood.

 

I did my XEs doors with dynamat - https://www.jaguarforums.com/forum/x...18-xes-274104/

Mass loaded vinyl isn't supposed to help much with road noise and it didn't, but it made a huuuuuge difference to the stereo performance which was my goal. I'm pretty sure a layer of sound insulation would have fit over the dynamat inside the doors, but I thought just doing the doors without anything else would be a bit of a waste.

You've covered pretty much all of the cabin in your list, apart from under and behind the back seats. Does your car have folding rear seats or are they fixed? A foam seal about 10mmx10mm around the portal into the boot often helps in cars with folding rear seats.

Please document your progress, I'm very interested in sound deadening

 

No I don't think the rear seat fold
I watched your before and after video of the sound system very nice too bad it did not make a difference in road noise that is what I am trying to do reduce road noise

 

If it's tire noise you are hearing, the best option is to try to find a quieter tire. If you happen to have runflats on your car, those are the worst for road noise and harshness. Some people add runflats to their car that didn't come with them, but if I buy a car that comes with them from the factory, I remove them on week 1 of ownership.

The other item is to make sure your alignment is perfect, because a bad alignment not only wears out the tires faster, but adds more tire noise.

And make sure all suspension bushings are good if you have an older XJ with more miles. Any metal on metal would transmit road noise into the chassis.

But when it comes to products like Dynamat, I have seen people rip their entire interior out to add those products on every inch of metal, and still get very little by way of results. Tesla's are incredibly horrible at isolating noise, and after many years, no one has found any meaningful solution on the owner's forums. The amount of road and wind noise seems to be a factor of the core engineering and design of the chassis that is very hard for you to reengineer in your garage. So if a car is too loud for you to enjoy, and it's not something broken, but just the way they all come from the factory, I have learned that you are better off cutting your losses by selling the car and buying one that you know meets your standard of quiet.

 

I keep a pair of Bose noise-cancelling earbuds in the car.
Complete silence.

 

I would agree with another poster that if you have noisey run flat tries you are in trouble. Also if you have 20" or 21 inch wheels - not good. Ideally you want 17 (wont fit) or 18 inch wheels with high profile sidewalls, like the old Jaguar XJS...

The quietest tire out there right now is the Pirelli Scorpion AS Plus 3
https://www.tirerack.com/tires/pirel...pion-as-plus-3

 

While I was researching the job I found there's two types of sound deadening - Mass-loaded vinyl (MLV) aka "Dynamat," and various insulating foam products such as Dynacore or Dynapad. MLV is used to add weight to things which helps to stop them vibrating and resonating, whereas the foam blocks some of the sound from passing through. The goal of my Dynamat install was to reduce vibrations and improve the sound which it did, but if I wanted to reduce road noise I would have gone with an insulating foam.

The ideal setup for sound would be to completely strip the interior, install MLV over anything that might vibrate, then install at least one layer of insulating foam over the top to try and keep the road noise out. Unfortunately my budget didn't allow both, but the MLV did a great job of improving the audio

 

My front tires are no name cheap HORACE a brand I never heard of tires that came with the car the rear tires are continental extreme contact all on 20" rims very harsh over potholes

I'm thinking of going with 245/45ZR20 for the front instead of the recommend 245/40ZR20 and 275/40ZR20 for the rear instead of 275/35ZR20

 

Seriously, do all you can to get down to 19 inch or even 18 inch. On the tire sizes you need to compensate - drop the width slightly and you can increase the sidewall. I did a ton of research on this - its all in my posts.

 

Do you know if XE or XF wheels will fit the XJ most XJ wheels are 20" I want the OEM look so I will get XF,XE wheels

 

Just started my sound deadening What do you think? Back seat and truck lid

 

Doors





What kind of speaker is this does not move in and out