Noise Reduction

[HoleshotHolset]

Good comment Colin... . this should help us save some $$, time, and weight!



Matt

 

[RedRamer]

You might be right CCahill, though I didn't want to take a chance once I got the cab mucked out I saw all kinds of Dodge stickies on panels and a large tar type one on the floor.

I laid / shaped / and glued 2 sheets of lead inside the cab and we pulled the trailer this week-end. The wife had this to say... It was a significant difference in sound... and I have to agree. The radio is at normal level and it sounds 200% better, we can talk at normal levels, I don't get that anoying harmonic noise at 2k revs, the Cummins still sounds good and basically that's all we hear. It does sound like it's in the basement in a closed room tho. Oh ya, and I can now hear my rear end humming tho I think that's about normal for the mileage, but I never could hear it before.

I had a friend who is an environmental engineer do a professional sound test before hand at highway speeds and I'll have him back in as soon as I get a chance, to see what the level is now.

When I get a chance I'll post the results and pictures I took.

goober

 

[HoleshotHolset]

Did those lead sheets have warning labels on 'em?



"This product contains substances that are known to the State of California to cause cancer... "



So long as you're not in CA, you're all set.



Nice work, I can't wait to hear about the results... (pun intended).



Matt

 

[Lsfarm]

I may have to..

I finally found the time to pull the back seat again, and added a sheet of lead to the back wall. I may need an EPA warning sticker for the cab window! This lead sheet came from Canada, [Goober's source] and probably would be difficult to find in the States. [because of the EPA]



The back seat area of the cab is noticably quieter than the front section of the cab. When driving on the freeway, if I recline my seat back and get my head into the back seat area, the drop in sound is quite noticable.



I guess this means that I need to do some sound reduction on the front door panels. I haven't decided what I will use on the doors, probably the 'dynamat type' bituminus sheet panel deadener first.



If I keep adding lead and heavy 'soundstop' foam I may have to upgrade to bigger injectors!! Oh wait, I did upgrade to stage 3's!! [I love them!]



A couple of other 'operation quiet Cummins' projects are going on right now, maybe they will report on their progress. Mike? Denis?



See Ya all in Muncie! [I got the time off work!]



Greg L [The Noise Nazi ]

 

[RedRamer]

I've been too busy to post, but here goes...

I got 2 sheets of lead put in and the cab is back in order.

The sound test came in at +- 2-1/2 db less than before on the low end and hardly any change at the top end of the frequency scale. The tester said that is a 75% drop in noise and according to him most of the noise drop is in the lower levels area.

He agreed that the cab noise was reduced substantially and that it was now a pleasure to ride in it.

What I covered was from the steering column to the rear panel window plus the 2 rear 1/4 panels.

It's a deadening sound now and I don;t think i need to do the doors. Most of the sound that it got rid of is exhaust sound and road noise vibrating through the cab. The cab acts like a speaker.

The engine sound is the same, just a deeper sound a bit muffled. At wot it's still load but only for short bursts.

He also said that there is no harm from the lead sheets. only when handling it, cutting and fraying, but I used a knife and gloves to cut it. It's only uncovered on the rear panel wall up to the window.

I'd post pictures but don't know how. Anyone know how to?

I could really tell the difference when I started the job. Cleaned out the cab of everything except for driver seat. Was it loud then.

As I covered areas, I could tell the difference. I could also tell where the noise was comming from and the rear 1/4 panels are a biggie. Floor over exhaust is also a big sourse of noise. Rear panel helps. You have to shape the lead into the panels. I used a roller for a basic fit. Then I contact cement the sides and roll it back on real well, hammer the sharp curves in and punch out the screw holes with a 1/2' copper water pipe.

Would I do it again... yep.

I love the sound of Cummins in the morning

 

[AlFischer]

I have been considering doing some noise reduction work on my new 2001 but I have also noticed that my wife keeps quiet instead of trying to talk over the noise. Not sure what the net result might be if I added noise reduction and she started talking again!!

 

[moparguy]

afischer, good one. I hadn't considered that possible downside of reducing the noise level in the cab.



Welcome aboard.



Ronnie

 

[HoleshotHolset]

It has been so long since I have driven with a full interior that I don't remember what it was like when I first bought the truck... .



My interior is totally stripped... . no floor covering or rear cab wall covering/'stuff organizers'... .



It's LOUD in the cab..... too bad I don't have an SPL meter..... would be interesting to see the reductions I get once I get my butt in gear and start buying the stuff to reduce the noise... .



I'm gonna try that stuff from Canada that rolls on... ...



Matt

 

[moon]

noise

Whats the address of that lead sheet from Canada that rolls on?

 

[sheldon]

I'm glad I don't have the noise problem... ... too many years of construction equipment and good rock and roll music

 

[RedRamer]

Hey, you guys are gonna need a special import license for this stuff. Glows in the dark, you know.



Canada Metal

8271 Lafrenaire

St - Leonard, PQ H1P 2B1

514-327-2011 FAX 514-327-7810



anyone know how to post pics?

 

[MikeBeggy]

Noise reduction project

I have followed lsfarms lead or lead and purchased my materials from the soundstop guys in Floida. I also bought a decibel meter from radio shack so I could measure any resulting changes. So far,I have only covered the cowl and firewall (on the engine side, what a pain). The results for such a small part of the overall project are amazing. I reduced my interior noise level by a solid 4 points on the A scale. This is a very noticeable change as noted by the wifes untrained ear. I am looking forward to pulling the interior and installing the rest of the foam. By the way, the soundstop products are really quality, probably why the results are so good.

 

[moon]

sound

Mike Beggy-whats the name of the product,whats the address or site?

 

[Lsfarm]

GSI

Yelloweyes:



Great Southern Insulation



www.soundstop.com Ask for Don.



TDR members get a 15% discount, just mention this site.



Email me for photos and info. About $300 of materials and a couple of days will make a huge difference in your truck.



Greg L. [The Noise Nazi]

 

[JGK]

Sound Stop on firewall/cowl

Mike Beggy,



I've considered the soundstop product on the engine side like you did. What was involved, how did you approach it, and what would you do differently?



My thought was to work out the stock foil-coated insulation and cut pieces to match using that as a pattern. That would go in first, then put the original insulation back in over the top. But maybe that can't be done with motor and/or transmission in place.



Thanks,

-Jay

 

[Powder Extreme]

So which is going to give you the best results vs ease of install and cost? I would think the lead would be the quietest, but is it alot more expensive and harder to work with?



Goober, how many sq ft. of the lead did you use? And did I understand correct that you used 2 layers?



Jerry

 

[RedRamer]

Powder... it's going to be tough comparing different methods.

Those noise meters don't tell the whole story. Your ears are 100's of time better than the machines and it's the type of noise that makes a difference. Only way would be to test run different rigs.

From everything I read, what it boils down to is adding mass to the panels. Whether you use lead or other commercial products, weight is what counts.

I used 2lb per sq. ft. lead. You can also get 1lb and doubleup here or there. I got 2 rolls of 4'x8' = 32 sq. ft x 2 x 2 = 128lbs and used about 110 lbs of it in the cab.

Now the reason I went to lead is. .

1) $400 bucks US for the coverage I wanted is at least $750. 00 Cdn after you add shipping, cross border duties and taxes... .

2) lead is very thin (1/32") and did not affect the fitting back of the trim and carpet at all.

3) It cost me about $110 Cdn for 2 sheets + another $50 for shipping.



If I was to do the firewall section either front or rear or outside panels (skins) I would not use lead as it's a pita to try and glue that stuff up in there with the wires and everything and probably a lot easier to peel and stick it in pieces... . but you know what, I ain't touching the firewall anyway cause I still want to hear that engine.

 

[Powder Extreme]

Goober, that settles it! The lead is the way I am going. Only 1/32" thick? Wow, I would think it would be pretty easy to install on the doors (all 4) right underneath the plastic door panels, which would be a heck of alot easier than trying to work the stuff inside the doors.



Also, I see you didn't add any to the roof liner, anybody have any comments on whether or not that would be beneficial?



LSFARM, did you have any issues with importing the stuff into the U. S. ?



Jerry

 

[RedRamer]

Can't help you with the doors as I haven't done them.

I'm opening them up soon for keylesss entry sys I'm putting in and might stick on a few pcs I got left over on whatever I see in there.

 

[Joel Richards]

I just received my b-quiet in the mail yesterday , but I have heard that doing the doors are a real PITA because of the clips that hold the trim to the door all break off - anyone have this problem??



Thanks

Joel