Excessive wind noise

[bvs]

I have a 03 United specialties on a Freightliner M2. It has loud wind noise at 65 mph from the upper sleeper area above the cab. I cant hear the radio so I shut it off. Does anyone have this problem? I am wondering if a visor or bug guard may direct the wind above the gap between the cab & sleeper. Thanks

 

[Bob86ZZ4]

It's a nice looking truck. Mine is similar. I don't notice a lot of wind noise. But my cockpit is very noisy. I wonder if you might want to do a sound deadening attack on the cockpit? Didn't Doc do one on his and document it pretty well here? I think he was pretty happy with his results. I wired up two headphone jacks to my cockpit stereo. And I use closed headphones which block out ambient noise. I only listen to the headphones when on the open road. I put a switch to shut off the speakers. That way I can listen to what I want to and the people riding can do whatever they want. It works well for me.

Welcome to the forum, great to see another United Specialties.

 

[Doc Weaver]

Bob, you are correct. One of the downfalls of a Freightliner is the noisy cab. Don't get me wrong, I prefer the Freightliner.

The doors, floor and ceiling can be dealt with, but the large windshield is just something we are stuck with. (excuse the grammar). The local car stereo store will try to get you to use dynamat everywhere. Although Dynamat is a decent product, there are different tools to use for different problems. Dynamat is great for noises from creaks and squeaks. There are barriers that are good for sealing out road noise and absorbers that are good for ambient noise. The one most miss in a truck is the rumble from the heavy duty parts under the truck. This is problem for a decoupler. A decoupler will stop the transfer of noise through the body parts.

I used Cascade Audio materials. In fact, I used their engine compartment material for my gen set box.

 

[bvs]

Thanks for the replies, I am pretty sure its wind noise because if there is a tail wind its acceptable. If there is a head wind its worse. My friend has a Columbia with a sleeper like Bob86zz4, sticks out a little over the cab, with a visor, his is quiet. I'm thinking its the design of the truck & sleeper but don't know what to try. I know its a truck but its really noisy. Thanks

 

[Gordy-TC]

My NRC/Century has a sleeper similar to your M2 configuration but does run the OEM windvisor. Mine doesn't seem to be too bad but I remember Freightliner suggesting double insulation in the firewall, cab and floor area, which it has.
So far the cab noise is acceptable and I drive it at or slightly above the posted road speeds of 75 mph.
I don't see how the visor would lessen the noise as all it really does is scoop the wind from the windshield and fire it between the cab and overhead bunk. I wonder if the noise is coming from the boot between the truck and conversion??

 

[bvs]

I put a pool air mattress between the cab & sleeper, went 65 mph and cant say it was much better. Maybe it is the area between the cab & box (boot) as you suggested Gordy. I will keep working on it. Thanks for the replies