Has anyone put sound insulation in a 4th Gen? I've got a '96 Infiniti I-30t and ordered a big roll of Brown Bread, plus the Hoodliner, plus some Lcomp for the firewall area. The Greddy cat-back exhaust is loud, but engine noise and road noise seem to be the biggest annoyances at road speeds.

If I had enough stuff, I'd line all the doors, the floor, and the trunk twice. But, since there is only 70 sq. ft. of Brown Bread, what are the best areas to do? My plan is to do the doors, floors, and rear deck with the Brown Bread dampener, and add the Lcomp absorber (only 8 sq. ft.) at the front. The hoodliner goes under the hood and is supposed to help stop engine noise from coming up through the windscreen.

So, who has done this? Is it worth it? Would I get better results applying the Brown Bread somewhere else, like the trunk? Or two layers on the floor and skip the doors? ANY TIPS WOULD BE APPRECIATED.

I bought a decibel meter and will measure the existing noise levels on the highway, then will report back with photos and new noise measurements after the installation.

I cannot use the search feature on Maxima.org, but I would appreciate it if anyone could link me to a thread where this was already discussed. Thanks.

 

I am doing the same thing. But I am going to use two layers of peel and seal. I am going to put it behind the wheel wells( most noise comes from there) and under the carpet.

BTW, where did you buy a decibel meter? and how much.

 

I found one at Radio Shack for $50, but I signed up for a Radio Shack MasterCharge at the same time and got a $20 discount. It seems to work pretty well with a range from 50db to 120db. It also has two settings for decibel readings, a very wide range that hears almost all noise, then a narrower range that measures noises in the range that annoy humans most. On the narrower range, my car generates about 70db at 55 mph with the radio and A/C turned off. Again, my plan is to take more precise readings under various conditions, in both frequency ranges, before and after the insulation installation.

I agree with you about the wheel wells in the front. My plan is to take out the back seat and cover the whole rear area (leaving a hole for the ski pass-through). I hope that will block any noise coming from the rear of the car.

 

Where can I buy this peel and seal stuff? Thanks!

 

I guess I will take a laptop in my car and record the noise, LOL. I was hoping it would be like 10-20 bucks. I just want to know how hard it will be to put everything back in.

 

lowes or homedepot. 12.50 for a 6" x 25' roll.
I read that 2 layers of that is better than Dynamat Extrme.

 

The Brown Bread, which is a peel and seal, is available from

www.B-Quiet.com

What are you using Kevlo?

True, there should be a cheaper decibel meter out there, but I couldn't find one. My other plan was to take the video camera in the car, then dump it out onto my PC and watch the levels. But, I decided I really wanted to know what I was getting for my money. So, I bought the decibel meter. Later, I plan to change the tires to some B.F. Goodrich ultra-quiet rides.

 

Kevlo, is this what you mean?

http://www.mfmbp.com/peelseal/index.htm

 

Get some edead v.3

 

Many people have used it for sound damping, search for it on yahoo.

 

i have heard that peel and seal in the summer gives a asphalty scent... is this true?

 

I heard that too, I was a little hesitant about doing this. But then I read that those were lies and it doesn't smell at all. As long as you let it air out for a day or two. The smell will never come back.

 

i did soundproofing but i did it to make the stereo sound better but it does keep some of the noise out. i used dynamat all around i swear i must of added about three hunred pounds too the car. their are different grades of dynamat for the car i had to do the trunk because of bass rattle the doors and in little places but not the roof. the bass response is nice and solid. but the only bad thing is it's heavy.

 

Is this peel and seal stuff called peel and seal or is there a different name for it. I went to home depot and lowes and neither stores new what i was talking about. help would be appreciated. thanks guys

 

I couldn't find it, either. Based on the post above, it seems to be about the same cost per square foot as Brown Bread. I paid $2.34/sq.ft. for 70 sq.ft. from Brown Bread, including shipping. Still, it would be nice to know you can run out and buy some more on short notice. Some car stereo stores carry Dynamat (usually about $5/sq.ft.), and Circuit City carries some stuff called "Tsunami", which is sold in ten 1'x2' sheets (20 sq.ft.) for $109 (over $5 per sq.ft.)

Here is an interim report on my installation. First, this Brown Bread is thinner than I was expecting. It's basically sticky tar paper with a thin layer of aluminum foil. It sticks well, is pliable, and is easy to tear with my hands when necessary. I did the inside of my doors and the area under the back seat, with a double layer on the front side of the rear wheel wells (where the road sound seemed most likely to come into the passenger compartment). I also put a few pieces on the floor of the trunk where the metal would vibrate the most when I struck it. (I don't have enough stuff to do the whole trunk.) Also, I didn't completely cover the inside door frames. My Infiniti doors had some big holes in the metal frame, apparently to accomodate all different manner of potential stereo installations. I put the Brown Bread on the metal frame, but also reached through and put some pieces on the inside of the exterior sheet metal. I didn't cover it, but put on enough I hoped it would help stop vibrations and sound transference. (Brown Bread is a sound deadener, not a sound absorber.) Anyway, with just these changes, the car does sound quieter. At 55 mph, my decibel meter shows a drop of only 2-3 dB in the "human annoyance" frequency range, but I can tell a difference with the work done so far, particularly in keeping the growl of my Greddy cat-back exhaust out of the passenger compartment.

My hood liner came in yesterday and I applied it under the hood, directly over the liner that Infiniti already had in there. It seems to stick pretty well. My Lcomp sound absorption stuff also came in. (That stuff is much heavier than brown bread, and feels like two layers of foam with a thin layer of lead in the middle. (According to the website, that's exactly what it is.) It's only 8 sq.ft., which I plan to put at my feet and up the firewall.) There is no asphalt smell from any of these materials.

What's left to do now is remove the front seats, tear up the carpet, and to cover the floor with the brown bread, then add the Lcomp over it up by the fire wall. That should do the most of anything so far to keep out road an engine noise. Now that the doors are covered, the floor and the firewall sound and feel like the biggest source of noise and vibration.

(While the carpet is out, maybe I'll take it to a professional carpet cleaner for a better cleaning than it could ever get while still in the car.)

My investment for all this stuff is $300, plus many hours in the garage. Still, it was very interesting to take my Infiniti apart.

 

I found the Peel and Seal in the roofing section. i read it might under be the label Ice Guard too. But Lowes and Home Depot had it for me.

 

Final report: Last night I spent 3 1/2 hours removing the front and rear seats plus the center console, then putting Brown Bread and Lcomp down on the metal. I couldn't remove the carpet completely without removing the instrument panel, which I didn't want to do, so I just lifted the carpet up toward the center. That gave me enough room to work.

First, let me say that Infiniti/Nissan had a lot more cushion and soundproofing materials under the front carpet than I would have guessed. Still, adding the sound deadener, and especially the Lcomp, made a big difference. Even though that difference measures only 3 or 4 dB on my meter (in the narrow range), that is a surprising change when driving down the road. I particularly noticed how much better my stereo sounded on the way to work this morning. A lot of the noise from the tires and road has been absorbed or blocked.

It's amazingly simple to remove the front seats. I'll remember that in the future if I need to haul a big item. Removing the front passenger seat and the back seat creates a ton of extra cargo space.

So, was the change in cabin noise worth $300 and 7 hours of labor? Because I spend a lot of time in my car, including long road trips, it works for me.

 

Ok im kinda stumped on one thing here...
How is peel and seal or Brown Bread or whatever it is only 12.50 at Home Depot , Lowes but then on the internet its like 120. Should i just go with buying it off the internet? Thanks for the help guys

 

This makes me feel better. I wanted to hear that you could hear a noticible difference when you put this in. I will def do this soon.

 

I covered the floor and door panels in my old 3rd gen with Dynamat. The interior was definitely quieter and it gave the doors a satisfying thud when you closed them. I'd like to do the 4th gen sometime.

 

At Lowes I found some stuff called Tite Seal in the roofing area. It's a roll of adhesive tar paper with aluminum foil on one side, very similar to brown bread, but it was much thinner, so you would probably need two layers to match brown bread or dynamat. They had a roll that was only 4" wide by 30 feet long, but I couldn't find a price anywhere. I might go back and buy it just to finish my trunk.

Also, I did buy some new tires for the I-30t, and that also made a huge difference in road noise. My car is much much quieter now than it was two weeks ago. The main noise that is still bugging me is the exhaust growl from the stainless Greddy cat-back exhaust and muffler. I think I'll go back to stock on the muffler.

 

Remember, a +/-3 dB difference is either a doubling or halving of the sound level. If you cut 3 dB out of the in-cabin noise, you have cut in HALF the sound level. This is not only VERY likely given the materials that you have used, but it puts the sound level in the I30 on par with man true luxury cars, which strive to get below 62-65 dB.

This is very good work, and it is no doubt that you can hear the difference on the road. How much weight do you REALLY think that it added to the car?

Back when I was big into stereos, I used to read reports about this all of the time. To get the same effect as dropping 3 dB of ambient noise, you generally have to DOUBLE the output (wattage) of ALL of the amps in your system. This 3 dB increase will sound about 2x as loud as the baseline measurement. But if you can reduce the sound floor by 3 dB (as you have) it has the same perceived effect.

You have what, $250-300 invested? For a stereo guy to double wattage, even if he were working in the "theory" world where he was just calculating increased cost (amp A value difference as compared to the 2x-powered amp AA) and not actually replacing amp A with a brand new amp AA, it woudl cost thousands of dollars in many cases. On top of this, turining the volume up to double sound output is much, much more likely to damage your ears. (Sorry if that was confusing- I can clarify)

In your case, you have done things the smart way, increasing perceived output by dropping the sound floor. On top of that, you have done it far more cheaply than by replacing your ams, AND in this case you can enjoy the fruits of your labor even when NOT listening to the stereo.

Nice job. Get some pics up!

 

What tires did you get?

Also, by all accounts you lose only 2-3 HP by going back to stock muffler on aftermarket y/b/cat setups.

I did that with my WSP Y & B combo, and with the aftermarket muffler it was loud, droning, and obnoxious, but with the stock it is almost as quiet as stock.

 

Guys sounds like your on the right track.

From my experiences....dont use Dynamat, your paying for the name. There are other products like the Tsunami from Circuitcity which are just as good. I did not pay that much for my Tsunami, as said in before in this post, it was rather cheap. As for the Lowes and Home Depot ppl, the guys there arent going to know what ur talking about, you have to look around for their version of this product. I would assume its in or around the insulation area. What your looking for(as described earlier) is a thick tar paper with a aluminum foil side on it. Its like aluminum foil with a thin lining of black clay on it.

One more thing, this make be very easy to do and install and looks harmless but take my words of advice and use gloves when working with what i described. It will cut you like a razor blade if it hits you the wrong way.

GL

 

This is exactly what the Crutchfield website said, too, though I still don't understand it. If I had 70-71 dB of cabin noise at 55 mph (A/C and radio off), then why is a drop to 68 considered half the sound level? I haven't measured the sound since the new tires, but would guess it is now close to 65 dB at 55 mph. The change in tires made a huge difference.

The tires are Toyo Proxes TPT's. They were $400 installed.

As for weight, the 70 sq.ft. roll of Brown Bread weighed 20 lbs., according to the UPS slip. The Lcomp probably weighed about 10 pounds. (It's only 8 sq.ft., but has a layer of lead in the middle.) The hood liner didn't weigh very much.

The strange thing is, I drive a five-speed and had become very accustomed to listening to the engine as my cue to shift. Now I can barely hear the engine (except the exhaust drone), so my shifting is off a little. It's nothing major.

GL is right. I cut my finger tips three times installing the brown bread. This usually happened when I rubbed my fingers along the edge while pressing against the metal.

 

3 dB is a doubling or halving of SPL. That is just how it is done.

It is like the Richter Scale (earthquakes)- the increase is not such that a 4.0 is twice the magnitude of a 2.0, it is 100X (I believe).

Anyway, take it for what it is that a 3 dB increase or decrease is a doubling or halving.

 

Here are links to the only pics that show anything worthwhile:

http://www.carylawoffice.com/images/door.jpg

http://www.carylawoffice.com/images/interior.jpg

And here's the car itself:

http://www.carylawoffice.com/images/NewI30t2.jpg

I can't figure out how to get the pictures themselves inserted in this post.

I just checked the dB level with new tires. At 55 mph with no radio, no A/C, and no exhaust noise (while coasting), it was 65 dB at the lowest point, but that fluctuated a lot because of other cars going by me.

 

I edited the tags in your quote to show the pics.

That 5 dB drop is significant. Good work!