Objective analysis of cabin noise solutions

SeattleLion

There is general agreement that the 370Z is noisy. The sport package versions appear to be the loudest. There also is agreement that reducing the road noise would be a good thing.

Several solutions have been tried by members. Members report different results applying the same solution. Since "loud" is subjective, I suggest that members preparing to perform cabin sound reduction provide some objective data.

If you have an iphone, a droid, or a Windows phone, you can download an app (99 cents I think) for measuring sound levels. Since we are interested in "before" and "after" numbers, we are not really concerned with how accurate the absolute values are; just the difference between before and after.

How to do the measurements
Download the app and familiarize yourself with how to use it.
Before you install the material:
Find a road you can easily reach that you consider noisy. Measure the sound level between two points you can find again. Drive at a constant speed. Note that level. It should be in db (decibels).

After the material is installed:
Return to the exact spot you measured the first time. Take a sound reading at the same speed you drove before the installation. Note the sound level.

Post the readings as well as what you did to reduce noise in this thread.

Some notes on sound readings
The decibel scale is logarithmic. That means that changes are not linear...for example if you measured 85db before and 75db later, you didn't reduce noise by 12% (the difference 10 divided by the original 85). You actually reduced the sound level by 1/2. A 10db change down is 50% of the original.

So if you reduce the noise by 10db, you have cut it in half. However, that does not mean the sound is half as loud to you. The human ear is not linear either; so reductions in sound level do not necessarily sound quieter to the ear. This is one reason why subjective reports are hard to understand.

If you can help with this, we can compile some objective expectations for various noise reduction solutions.

FuszNissan

It's a sports car.

__________________
Mods: Too Many to list!
LouFuszNissan
ZDAYZ 2012

Dwight Frye

Yes it is a sports car. Bad answer, narrow thinking, and acceptance of something that is unnecessary. High cabin noise does not a sports car make, any more than putting a big-*** wing and loud exhaust on an FWD Accura makes it a sports car.
I would enjoy my Z on road trips immensely more if the road noise was reduced and it would take nothing away from the rest of the sports car experience. I don't expect it to have an interior noise level like a high end Mercedes, but I don't think that some effective engineering by Nissan to reduce the noise level of the car would have compromised anything else in the overall performance of the car either.

theDreamer

Sports car.....

__________________
theDreamer's Z // Fast Intentions // Uprev // GTM // HKS // TEIN
theDreamer's Silvia // URAS // GREDDY
Houston Zs // Facebook // Twitter // Instagram

m4a1mustang

They made the G37 for this reason.

__________________
- Steve

Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!)
LIKE us on Facebook!

phelan

...? I don't remember agreeing to that.

Like the others say - it's a sports car. If you wanted a quiet, easy ride...Infiniti dealership was probably right next door?

Chriz

get a new car

__________________
PW 7AT w/Sports Pkg
Hook Em!

VCuomo

Really, how did you come to that conclusion?

I've owned mine for almost a year and a half - it is not noisy.

And, as others have pointed out, it's a sports car...

BrianMSmith

Bloody hell, it is noisy. Maybe you don't notice so much if you're 20 something....I don't even like driving with the windows down anymore, because it's too noisy, but then again I LOVE quiet (when I can get it) because I have 3 young boys (Larry, Curly, Mo) who are very good at generating tremendous noise for long periods of time, and MY EARS are TIRED. That must mean I am old.

I am looking forward to putting quieter tires on this machine, but if I were that bothered I'd spend $800 on a professional dynamat job. No big deal. I've found that most cars and motorcycles need a bit of custom work to make them what you really want. Whether that's quieter, louder, smoother, or faster.

VCuomo

Well, I'm 50 something and I don't think that the Z is noisy - and it's my DD. If I run over loose gravel, sure all hell breaks loose. And it's a low-to-the ground sports car, so it's going to be louder than a sedan, even during "normal" driving.

It's not a quiet car, but it's not a NOISY car either - know what I mean? That's why I (and, I suppose, most of the others) objected to the OP's blanket statement that there is "general agreement" that the Z is noisy.

whoady4shoady

My ears are still ringing from my ride to work today.

c41006

I don't mind the noise

waaaasabi

I've actually done some research and discovered that the faster I go, the more noise the car produces - any solutions for this?

__________________
That's SOOOO not Raven!

Xan

Drive slower...


To the OP:
I have no issue with any noise, so it's not a general agreement, it's the opinion of a few.... As you stated, it's subjective...

Just out of interest, outside of applying noise absorbing material, what are these several solutions you are referring to?

__________________

SkyZ

i think that those buying this car knew full well what they were "getting into" and as such noise is not a problem for us. the reviewers might have a different opinion and thats they're problem, but i'm also perfectly happy with my car.

those who didnt like the loud noise pretty much just dynamatted it.