Dynamat

No I was too cheap to get a noise meter (cheapest was $75). However, I can make comparisons with my wife's Prius (completely stock).

The only thing I have to base off of is my current volume settings for my radio. Currently, I have it set at 25-30 on the highway and 20-25 in city with the windows rolled up. My biggest noise problems are other cars with loud engines and noise from the road (my tires are the next upgrade).

 

<div class='quotetop'>QUOTE(Tadashi\";p=\"84047)</div>

Hi Tadashi,

It would be awesome if you could borrow an SPL meter from a store (try the shops that do surround sound system calibrations, you might get a tech to do side by side comparisons just for rining around in the Prius and a mention on the site). Human ears are not reliable test instruments unless the differences are gigantic.

Looking forward to hearing your results.

 

I will see if there is a store around here that might have a meter. I think they say that a human can differentiate the change in 3db. If it is like my F250 diesel sound proofing, it will be a gigantic difference in sound. It went from a rumble of the truck to sedan like quiet. It really eliminated driver's fatigue on my 24-36 hr cross country trips.

 

Do you have a Radio Shack near you? They sell a decent analog SPL meter for $40. I use one to calibrate home theater setups all the time. Here is a link: http://www.radioshack.com/product.asp?cook...duct_id=33-4050

 

<div class='quotetop'>QUOTE(Tadashi\";p=\"84140)</div>

The smallest change a theoretical human can hear is 1dB. 3dB is half the power/noise. The problem is that we are trying to evaluate bang for the buck and if you only get a 1 dB reduction then its just not worth it. A 10 dB reduction (one tenth the power/noise) would be something truly impressive. Trucks are notoriously noisy but they are easy to quiet down. Cars have already gone through an NVH (noise-vobration-harshness) design stage at the factory and it ususally takes more work to get a meaningful reduction in noise (hence the heavy weight of the traditional dynamat).

My hope is that you will confirm an enourmous reduction in noise and we will all run happily down to the shop and get Dynamat Extreme installed in our Prii so we may cruise in bliss.

 

Human ears also perceive sound differently at different frequencies, we're especially bad at low frequencies.

If you have any friend with good home theater systems , a SPL meter is a must if they calibrated it themselves (vs. a home theater installer). They might have one. I find cool uses for my meter every day, though you run the risk of appearing unusual bringing it in public. :wink:

 

<div class='quotetop'>QUOTE(gschoen\";p=\"84191)</div>

That's funny. I live in the heart of Silicon Valley in California where no one would even notice if you were to wave around an SPL meter in public. In fact if you did it long enough you probably would get two or three people telling you better ways to do what they imagine you to be doing.

Also, gschoen is absolutely correct about the nonlinearity of human hearing. To get a better idea of how we would perceive the improvement that the Dynamat installation will bring, I recommend that you set the meter to the "C" scale or "C weighed", etc. This will set it to "listen" more like a human ear would hear the changes. That way of the change is small to us, we might not necessarily decide that it is a good investment. Conversely, if the noise reduction is huge in the part that we do hear then we would be more likely to get the installation done ourselves.

 

lol, Best Buy was cleaned out. I bought the last of their stock here in El Paso. You should have seen the tech's face when I got ordered it. "You want the ENTIRE cabin done?" he said they only usually do the trunk.

I will check out radio shack. They say they have one in stock and it is on my way home.

When they took off the doors, there was no insulation. Only a thin plastic covering (like a see through plastic bag) attached to the door by a black tar like substance. There were 2 sytrafoam blocks one in the door and one in the top of the inner panneling.

The reason why I do not think they did a very good job is there was one post where a deaf woman said the vibrations of the Prius drove her nuts.

 

<div class='quotetop'>QUOTE(Tadashi\";p=\"84198)</div>

Your description of the construction sounds quite standard for the automotive industry in this price/category range. No surprise there.

As for the deaf woman, I missed that post so I am glad that you mentioned it. It seems to me that the biggest factor in noise is what comes from the tires. There have been posts here that the Prius has quieted down dramatically after a tire change. My interest in the DynaMat is to quiet the cabin down regardless of tires so I can choose a superior performing tire without worrying about the noise factor. i will look for the deaf post and see what she had to say. Thanks!

 

Yep, tire changes are next month or the wife will kill me. I better get at least a 8 db drop or she will kill me once she finds out how much I spent. hhhmmm maybe I should not get the sound meter.

"But honey the box says 8-10 db drop." /runs from airborne household items

 

<div class='quotetop'>QUOTE(Tadashi\";p=\"84211)</div>

Oh man, sticky situation. Maybe one of your friends has a laptop with a microphone. I'm sure that you can find a free application that will display sound levels.

 

<div class='quotetop'>QUOTE(RBW111\";p=\"84219)</div>

That is definitely impressive. Which Dynamat did you have installed in each area?

 

I wish we could get it like the commercial for the luxury car under the waterfall and you do not hear any noise inside.

 

<div class='quotetop'>QUOTE(Tadashi\";p=\"84232)</div>

You can probably get a similar effect by using a combination of DynaMat products (this is the method recommended by DynaMat). It just takes a dedicated installer who knows her stuff and the appropriate financial commitment.

 

RBW111 - did they do any part of the rear door on your Prius?

 

update: It took another 7 hours to line the floor. There is still about 4 sq ft left to do in the trunk and back side wheel well. Total it took about 68 sq ft of dynamat. I got another 24 sq ft (92 sq ft total, about 50 lbs) to finish the trunk and roof for a grand total of $1010. My sound readings in the car in city (with gas engine and elec engine running) is about 50 db. The highway at 60 mph is about 60 db (smooth surface roads). The type of road makes a big difference so (I can really see the meter needle jumping around when the roads get bad). The tires will be changed next month. The tech took pictures so I will post them as soon as they print me up a set.

They did not dynamat the spars running across the floor nor did they dynamat under the battery. They were not comfortable with messing around with that. It was pretty neat to see my Prius taken apart to see where stuff was.

 

I'd love to have this done to my car, but I don't know if I can find anyone in this area that I would trust to do the install.