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Open for suggestions on how to make my metal top quieter

Discussion in 'Intermediate CJ-5/6/7/8' started by sac13, Mar 12, 2010.

  1. sac13

    sac13 Come oooonnnnn summer....

    Ok. My aluminum half cab is not selling and I'm not giving it away so it looks like I'm going to use it. The biggest problem I have with these metals tops is the noise inside. Has anyone addressed this? I'm wondering if I can get some spray in flocking or foam or something to dampen the sound. I'm not an accoustic guy, but I believe most of the noise is strictly echo. Would a coat of spray on rubberized undercoating do the trick? I hate to go that route and have it not work. That stuff doesn't come off!!!

    Let me know if anyone has any ideas!!

    Thanks!
     
  2. Mike S

    Mike S Sponsor

    Dyna mat.

    Go to a car stereo store.
     
  3. dauntless_powered

    dauntless_powered SUB COB 2024 Sponsor

    Pretty pricey to do an entire top I would think in dynomat...there are a ton of options and I am sure there are guys here that have dealt with this
     
  4. bkd

    bkd Moderator Supreme Staff Member 2022 Sponsor

    I would think it's gonna take some sound deadening material of some sort......I had thoughts of doing that on my 6 top before I sold it, at least with a half cab it won't be nearly as expensive
    I'd google " sound barrier material" and see if you can find reasonable priced sheets
    Jim
     
  5. this may be stupid, but works in my head.....

    get some of those foam rubber "anti fatigue" mats, cut them to fit and glue them in. would dampen sound pretty well i would think, and if you cut and glued neatly would probably look decent.
     
  6. jpflat2a

    jpflat2a what's that noise?

    mat and carpet the floorboards and the firewall as much as you can
    that's where the noise is coming from
     
  7. Patrick

    Patrick Super Moderator Staff Member

    X2. The top is just reverberating the noise.
     
  8. unclebill

    unclebill Banned

    Peel & Seal is the cheap alternative to Dynamat. This is the stuff you get from Lowes Hardware. It is the same as the original Dynamat but a lot cheaper.
    $15.00 for a 6in. X 24ft. roll. It's very, very close to Dynamat other than the price. It has a 40 mil rubberized aspalt sticky back, two layers of high stregth polymer film over a reflective aluminum surface.
     
    Last edited: Mar 13, 2010
  9. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Carpet and padding on the floor is very effective. That will make a big difference. It is true that most of the noise is coming through the floor, from the engine (especially the exhaust and fan), gears and tires. I did that to two of my previous Jeeps, putting jute carpet underlayment under indoor/outdoor carpeting. The jute will soak up water though, so you want to be able to remove it if it gets wet. I would certainly try carpet and padding first.

    There is a flooring underlayment in the home centers now that is specifically intended to reduce the transmission of sound (for between floors in apartments and such). That might be a good alternative to the jute padding.

    Thinking about this, I wonder if a soft top seems quieter than a hard top because of the reflections. The soft top is more transparent to sound, which lets the sound out without reflecting it back into the cabin. After you insulate the floor, you could try something on the roof that both breaks up and absorbs the sound. Eggcrate foam would be particularly good for this; this stuff is used for hospital beds to help prevent bed sores.
     
    Last edited: Mar 13, 2010
  10. grannyscj

    grannyscj Headed to the Yukon

    I Hush matted the tranny tunnel and the angled portion of the firewall, then used jute backed carpet (I used snaps so I could remove it if needed).It basically got rid of the noise coming from that area. Now we just hear the soft top which isn't too bad until you get past 60 mph. I would do that first. There is undoubtedly noise coming from the top too. Pete used to have a full steel top and you'd get drumming from the metal flexing when you'd hit a good bump. Your half cab may not be as bad, so try the floor first. I'd think a rubberized undercoat would work but that's just adding more weight way up high and peel and stick stuff is not going to look too good.:v6:
     
  11. unclebill

    unclebill Banned

    i am going to glue thin carpet over it.
     
  12. $ sink

    $ sink Gazillians of posts

    Make sure all holes through the firewall are sealed, undercoat the front floorboards from the underside, make sure your shifers are sealed to the trans hump with good fitting boots and undercoat the underside of the trans tunel. you would be amazed at how much quieter it will be. as for the top, the wide sections of panel between supports are going to give you the most reverberation, even small areas covered with sound absorbant material in the middle of these areas will make a big difference.
     
  13. Cantilope

    Cantilope Member

    I used some Elemental Designs e-dead in my truck and it works really good. The stuff at the home store is most likely an asphalt backing. I would recommend this stuff instead as I hear the asphalt starts to melt and get a little soft in the summer heat. This also has an aluminum surface that is supposed to reduce reflective heat as well. I did a fair amount of research to do my truck and this was the best/cheapest stuff above the asphalt. I would maybe even use it on the floorboards and firewall. I took my brand new f-150 ripped out all of the carpet and seats and placed this stuff along the floor and walls inside the doors every flat steel surface. I have a db meter and dropped 5-8 db road noise after this stuff was installed. If you tap my door panel with your knuckle it sounds like a 1/4" plate not a tin can. Not sure if this would speed up rust in a Jeep... but on the bottom of a top such as this would I think it would be fine.

    Noise is transferred through materials from vibration. If you can keep the panel from vibrating in sympathy with the noise it will not transfer the sound wave and pass through. Couple this with a sound absorbing jute to catch the left over vibrations that do get through you would could make a considerable difference. The car audio folks are big into noise deadening, do some searching on that.

    One other thing to note too, not all foam is created equal. If I recall there is opened and closed cell, you need a closed cell and there is a special type for sound deadening. I believe the egg crate is open and does not absorb enough to bother.
     
  14. sac13

    sac13 Come oooonnnnn summer....

    Wow! I didn't expect so many good ideas to try. I was planning on using Herculiner on the floor like the last CJ since this will see more muddy boots than flip-flops, but I guess I can replace a $20 piece of carpet every couple years as it rots out from all the goop in the foot well and put that over the liner. I guess I never considered the fact that the noise is actually generated from outside the cab. Good points. I work in the auto industry, so I may be able to get access to some actualy accoustic sound deadener. A large piece spanning the top may be all I need on the top.

    Thanks again for all the great ideas! If anyone else has any good suggestions, keep firing away!
     
  15. coby61

    coby61 Stupidiotic Member

  16. jasonjp62

    jasonjp62 Member

    I have herd good things about the lizard skin
    Posted via Mobile Device
     
  17. Yankeefist

    Yankeefist Sponsor

    Just go to your local John Deere dealer and have him order you the material that is used inside the older tractor and combine cabs. It is a 3/4" or 1" foam with a black perforated vinyl cover bonded to it. They even handle the spray adhesive to glue it down with. I have used it to line the inside of a couple of old aftermarket tractor cabs and it really quiets things down. Looks good too.
     
  18. unclebill

    unclebill Banned

    http://www.tractorseats.com/c-94-cab-foam-and-adhesive.aspx
     
  19. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    I like the idea of carpet as long as it's shag.
     
  20. unclebill

    unclebill Banned

    yeah,
    i am going with avocado and gold paisley shag myself