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B-Quiet install and dB results

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9.3K views 14 replies 8 participants last post by  B18cRturbo69  
#1 ·
I Just got done installing B-Quiet sound insulation in my 2000 Insight. The noise was making me crazy....I am a little less crazy now. First, the instructions on this sight explaining how to remove the door panels are right on! Don't worry about it, just follow the instructions exactly how they are written. I had no broken clips or misfit panel when done.
I am an Audiologist and have a good sound level meter I used to take the following readings.
Before the install of B-Quiet in the doors and in the rear well, the sound level reading are as follow. All measurements are in dBA, the correct setting for the sound level meter.

Before the B-Quiet:
At 30 mph it was 70dB at my right ear in the cabin
At 55 mph it was 79 dB """"" """"""
" 65 mph "" '' 75 db
" 73 mph it was 78 dB

It was over 80 dB hitting bumps

================================

After the B-Quiet install

At 30 mph it was 63 dB
At 55 mph it was 74 dB
At 65 mph it was 72 dB
At 73 mph it was 76 dB

So....it can be seen that B-Quiet does help some with the cabin noise. It appears to help the most at lower speeds and can be subjectivly notice at the lower speeds. At higher speeds, it seems harder to notice. I also stuffed "eggcrate" foam in the viod at the right of the well when standing in the back of the car looking forward, as well as around the spare tire. I also bought a cargo mat and intalled it over the rear cargo area. I did not insulate the surface behind the seats or the floor as I read this makes little difference. Please let me know it this is so. I bought 50' of B-Quiet and have over half of the roll left.....so.....buying 2, 12' rolls is enough to do the job I show here. You do not need the 50' roll......
Now....I have 50 psi in all tires and the reading are subject to different types of road surfaces. On smooth asphalt it is much quieter than on the rough, older grooved roads. Most reading were taken on the rough roads.
I have attached some pictures....I look forward to any comments on my job or on tip on how to further improve the dB level in the cabin.
 

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#2 ·
PS......I also have and use custom musicians ear plugs with both 9dB or 25dB filters in them. They are great and are a much easier way to get some quiet in the cabin. Go to an Audiologist and have a pair made for you. They are great if you can get used to wearing earplugs. They are also great for loud music. They preserve the sound spectrum and lower all frequencies equally. Not like the yellow foam EAR plugs. You can still hear the person next to you clearly as well as the stereo. Everything is just a little lower.

Hb
 
#4 ·
Yes....the earplugs are high tech. They are made for musicians so they can hear all the frequencies from their insturments evenly. Just like without them. A 9 dB attenuation is not much. Just enough to make you feel like you brain has not been on the cheese grater after a few hours of driving.....you can hear everything, just quieter...

Hb
 
#5 ·
So, the question is..... In your opinion, was it worth the expense and labor?
Also, what would it cost to purchase 2 12' rolls of B-Quiet?
-Don
 
#6 ·
I have no idea if it would be worth it to you. It was to me as I like doing stuff like this and I don't really worry about the money........What is your tolerance for constant loud noise....Mine is quite low...almost enough to not want to own a Insight. Almost.......

As far as the cost of B-quiet...goggle it.....

Hb
 
#7 ·
honeyboy said:
I have no idea if it would be worth it to you. It was to me as I like doing stuff like this and I don't really worry about the money........What is your tolerance for constant loud noise....Mine is quite low...almost enough to not want to own a Insight. Almost.......
I wasn't expecting you make a decision on my part, I wondered if YOU were satisfied with the result. I too have a problem with the noise level in the car, especially with the tires pumped up for max mileage. I'm not familiar enough with db ratings to get a feel for the difference just looking at the numbers. I suspect a large portion of the readers of this thread are in the same boat.

I'm most bothered though with wind noise. If Honda had just made the rear windows so they'd hinge outward a little it would have provided the occupants with much better ventilation without having to crack the side windows and suffer the associated wind noise. I realize B-quiet won't do anything to help this.

honeyboy said:
As far as the cost of B-quiet...goggle it.....Hb
Okay, sure, I can do that. I just thought since we share information with each other here and YOU just bought 5 rolls, mentioning what half your cost was (2 1/2 rolls worth) would be of general interest to anyone who is considering this project. :roll:
-Don
 
#8 ·
Devin, The Decibel scale is non linear but essentially 10 Decibels equals one Bel which sounds twice as loud but is infact 10 times as powerful. At 30 MPH there is a 7 Db decrease which will sound significantly quieter but not quite half as loud.

There is a comprehensive explanation of the decibel system here.

http://www.micworks.com/freeinfo/decibel.htm
 
#9 ·
it looks like you got the b-quiet "ultimate"?

....doesn't seem like the b-quiet made a significant, noticeable improvement....
......but since you have so much left....why not try 2 or 3 layers where its possible to do so????????

I wonder if the dynamat would be any better (since price is of no concern to you).
 
#10 ·
Hi,

Sorry I was gone from the board for so long.......Well....Yes...I do feel it was worth using the B-Quiet. As for putting 1 or 2 modre layers, I think I will not. It seems my mileage has dropped a bit from installing the mat in back, the B-quiet, the arm rest...Maybe the extra weight?? It is quieter in the car since the B-quiet install. I was thinking about doing the floor panels but was not confident about getting the rugs removed and replaced and having it look the same. Any advice on this? I also read that the floors do not make much difference. Please advise.

Thanks
 
#11 ·
Science teacher here, so bear with me. :D

The sound you hear in the car is not so much sound coming in from the outside.
Is it jackhammers, trucks, or large flocks of birds bothering you? I doubt it.

Most of the sound is the sound generated by the car itself.
Most of the sounds you hear are coming from the INSIDE of the car.
Most of it is vibrations that are transfered by the metal ( and glass ) of the car itself.
The body of the car is a giant resonator.
A deaf person would be able to "feel' all those vibrations, no matter how much foam or "B-Quiet" stuff you put into your car.
You can't stop the whole car from vibrating.
Softer tires would be 10x more effective ( probably ) than all the padding in the world.
A better, isolating engine mount would help a lot too, but at what cost?

The ear plugs are the #1 best way to go, hands down.
I applaud your testing with the dB meter.
Unfortunately, in my book, you clearly proved the efforts you took were... nearly... useless.
2 or 3 dB either way is within the realm of testing error / average variations also.

Thanks for sharing. I always like a good experiment!
:) -John

P.S. dB scales are always relative scales, not absolute scales. dB means "x compared to y". They never tell you how much of something there is. The orginal "Bell" ( later shortened to Bel ) was the amount of voltage drop through 1 mile of telephone wire, back in the day.

The "number" is really 10x the exponent. So 120 db means "x is 10^12 times more powerful than y".
120 dB is 1 trillion times more powerful than some reference, y.

With sound, the threshold of human hearing is given a value of 10^1 or 10 dB.
A sound of 75 dB is 10^7.5 times as powerful ( energy wise ) as the smallest sound you could possibly hear.

We could just as easily measure earthquakes in dB and it would be just as meaningful.
It's just not traditional to do so.
 
#12 ·
Hi Honeyboy. You managed to reduce the power of the sound by 3 dB at 65 and 4 at 55. 3 dB is the half power point so you actually reduced the force on your ear drums by half. I'd say that is worthwhile. The added weight should not really change your mileage, but you may be driving faster now that the car is quieter, and that would. ;) The sound proofing would likely decrease the higher frequencies more readily whereas the meter would likely sense a different range unless specifically designed to respond to the Equal-loudness contour*. Likely the percieved benefits are greater than the measurements indicate.

See: http://en.wikipedia.org/wiki/Equal-loudness_contours
 
#14 ·
I agree with gpsman1 about where the sound is coming from but feel road noise is the most prominent especially on coarse surfaces.
When I slip onto a silky smooth surface the car goes extremely quiet indicating this to be the main culprit.With the hard tyre compound,light weight suspension components this road noise is fed directly to the shell.
Without adding weight or a complete redesign only changing the tires to a softer compound would give a result.
Other manufacturers have solved the problem with heavy subframes or suspension components that act like an anvil thus absorbing and canceling the sound/vibration before it reaches the shell where its amplified.
Vibration dampers are put on driveshafts and even the ends of crankshafts to cancel unwanted noise and vibration so maybe something could be added to the lower suspension arms.

DGate