Sound Damping a Cab

[the old grind]

GP, I have most of a twin bed sized 'waffle' foam if you don't mind pink to try it out, esp like on the cab roof or something. I agree with the others that the first few tricks won't show what effect the last few details will. (PM coming..)

 

[GPintheMitten]

GP, I have most of a twin bed sized 'waffle' foam if you don't mind pink to try it out, esp like on the cab roof or something. I agree with the others that the first few tricks won't show what effect the last few details will. (PM coming..)

Thanks for the offer but I'll pass on the pink. Let me know if you want help trailering or loading your rig.

 

[the old grind]

Sure. It's just 'test' foam (lab rat stuff) but expendable as such. Blue WF I have is much better, more dense, but smaller pieces, quantities. Would like to see how your cab turned out. Should I wait 'till you have the BH in hand too?

Haven't been by your place since warm weather (Fall sometime) & a new GF last Spring. My bad for not catching you home or inviting you to see my 10 by now. Will atone as best I can, with some stories and updates on new gear. (she moved on, btw .... whew!)

 

[GPintheMitten]

Stop over any time. I'll let you know when I get home with the backhoe. Probably get it next week sometime.

 

[PILOON]

I played with reducing noise in aircraft a bit.
Sound caused by large surfaces i.e. cab roof can be greatly reduced by taping a big X from corner to corner using self adhesive roofing membrane, Adding a liner with a foam backing also will help. Felt even better.
Rubber grommets wherever something penetrates the firewall helps also.
I鐡 suggest that the underlay material used for laminate flooring would also be a good sound killer, not foam type but the other denser materials.
High pitched sound like turbos benefit from lead shielding.

Bell 206 helicopters used dense quarter inch foam with thin laminate of lead to dramatically reduce turbine noise. The product was self adhesive.

My tractor cab has all these tricks and the noise level is most tolerable.

A cessna I once owned was treated this way and I could actually hear the valves when flying.

 

[locknut]

Some very good suggestions here.When I built my steel cab I couldn't believe how noisy it was-like sitting in a big drum.The roof was 5/8" thick roof underlayment with the bottom covered in gray speakerbox carpet.So,in tackling this problem I employed my old subwoofer building skills to tame the resonance. I added a center cross brace offset around 3" so as to make the two remaining areas resonate at different frequencies.It helped a bunch.


Edit;
I just checked over your cab-looks very nice.I see you have two braces on the roof so the three areas might be reinforcing each other.Three offset pieces may help here.The Plex panels are very large so I think I'd try the X taping thing and experiment with a roll of adhesive backed magnet tape for maximum mass dampener effect.

 

[tman1020]

i just installed a steel cab and was also surprised at how loud it was. mine is also mostly glass so what i did was buy about 6 rolls of 1/2 inch thick x aprox 1 inch self stick foam weather strip and and run it between all windows.then i bought air conditioner foam and used that to fill all little openings around all levers and stuffed under dash. lastly i put foam(kinda like eggcrate foam)around seat well. this all helped a lot i no longer need ear protection.. mine came with a sound deading head liner i think that this is a very large help also. hope this helps

 

[94BULLITT]

I built a cab this winter. Made out of steel and plexiglass mostly, with a plywood roof. There isnt any sheetmetal on the cab. Its totally covered in plex.

There's a lot of noise in this thing. It is solidly constructed and not rattling but its the engine noise that is amplified in the cab.

What have you guys with cabs done to reduce the noise level? I can put some kind of headliner in and can do something with the floor but the rest is plex. I wore hearing protection when I used it last week but would like to quiet the cab down as well. Any recommendations on what to do to the roof and floor?

Thanks.

The L4240 has a thin rubber mat on the floor, a piece of foam then the floor mat.

I don't know if undercoating or truck bed coating would help dampen the noise.

 

[jenkinsph]

The L4240 has a thin rubber mat on the floor, a piece of foam then the floor mat.

I don't know if undercoating or truck bed coating would help dampen the noise.

Forty years ago in the sound reinforcement business guys would use undercoating on the outside of Altec horns to reduce ringing. The undercoating can help but sure is messy to deal with when taking stuff apart. I suspect the multi layer approach with different materials that Kubota uses will work better to dampen a wider range of frequencies.