Should have put this in another section ... nobody sees this! Oh well

 

All this information is great!

Though, I didn't understand what you were talking about with regards with the rear seats.

I wish this thread got more exposure!

 

I have to say its nice to see it piece mealed together to find the differences in noise. But I also have to say you said you didnt wanna gut the car, but you pretty much are 80% the way there once you have the door panels, console and rear cargo panels out. A few seat bolts and pull the carpet out and its pretty much gutted, you could have gone full bore and done all the sound deadening you need. Noise in this car aside from the motor is mine and my wifes biggest complaint. Its not quiet at all.

 

Update: Had the front cowl off last week to change the spark plugs - while I was there I put dynamat on the underside of the firewall that is under the base of the windshield. Goal here was to reduce noise coming off the top of the strut towers.

The actual separation of engine from cabin is the cowl tray, but that is also a drainage tray. For that reason I recommend not putting any insulation on the back of that, and also not putting any on the front as that is very very close to the hot exhaust and cat.

It makes a big difference! Glad my suspicion was right. I think it could be good to spend more time getting more coverage, but I was rushed and the surface is not very uniform. I'm happy with the sound reduction. You can still hear the engine and the valvetrain, which is good IMO - in a car this slow, I wouldn't want the engine to be silent, that works better in large luxury cars- but road noise and potholes thumps intrude into the cabin less. Worthwhile doing.

 

Awesome! Though I'm having trouble picturing where that is - any chance you have a photo?

 

When I'm posting from my phone, yes. In this photo you can see the base of the windshield and also the tray below it. When the cowl is off like here, you can see between them, for example you can see the strut tower top. Above that you can see one piece of dynamat*. That's against the firewall which curves up and forward to meet the base of the windshield.

From a noise perspective, it would be best to have the strut tower and firewall in front of the windshield ... But that decision is one reason for the Fit's compact design. Especially the GE.

 

Thanks for the detail, fujisawa! I see how a lot of road noise would come up the strut - interesting that such a small piece of matting would help dampen it. I'll have to try it out.

 

Oh you maybe misunderstand a little, there are a lot MORE pieces that are up underneath and can't easily be photographed! but yes if you made them contiguous that would be more effective.

 

Updaaaaate

Insulation up under rear seats today. Found a good material for this. Think I've Included enough of the seat you can get a sense what I'm talking about.

Although there IS padding beneath ones feet there are also areas of the floor pan that are nothing but a single layer of metal. These I imagine do interior noise no favors...

 

A good deal of the reason luxury cars are so quiet is they have about 400 pounds of sound deadening material in them. Now, Lotus invented a cool way to quiet their cars decades ago: they effectively made the whole interior the equivalent of noise cancelling headphones. A microphone listens to the ambient noise and speakers put sound out that's 180 degrees out of phase with it, cancelling it out.

 

That's old news.
Years ago a co-worker purchased an Acura ILX with that tech.
After a week with her new car, she was furious. The car was as noisy as a base model Civic.

 

Yeah, the tech doesn't work. Dad has it in his CR-V and we have it in our 2020 Accord. If it's doing anything, I'd hate to know how loud those two vehicles would be without it. Our 2020 Accord is already louder than my F150 on 34" offroad tires.