I installed sound isolation to my rear wheels.

Thanks for the tip. I just ordered some. I'm going to double layer the wheel wells. I'll do the inside of the wheel wells inside the car as well as the outside of the car

 

Real sign of the times, that when I glanced at the title of this thread I read " I installed SELF Isolation to my rear wheels".

 

Actually no big deal....I think people get it...
But isn't the more correct term Sound Insulation?
Even with the linked post, a box refers to the materials as sound INSULATION.

I think sound ISOLATION is a padded cell.

 

That's so funny that you thought you read it but later realized that you read it correctly.

 

As you discovered, you can't change the title, but if you click on the "report" button you can ask a moderator to change it. But then that would take a lot of the fun out of this thread. We all make typos and most of us make fun of them. Including me.

 

Actually, for electrical/electronics/audio applications, both terms are quasi-interchangeable (but are often misused ).

In audio applications "insulation" refers solely to the use of absorptive materials. In RF (electronics) engineering applications absorptive materials are used to "attenuate". In both audio and RF applications, "Isolation" refers to the use of both absorptive and reflective materials to block/absorb sound or electromagnetic energy before it can propagate to, or intrude into, a volume. E.g. a Screen Room or Faraday Cage "isolates" enclosed electronics under test from external noise sources.

In electrical and thermal applications, "insulation" refers to material/components used block or restrict current/thermal energy flow to a load or volume. "Isolation" refers to blocking DC current with a transformer or electrical isolation via optical coupler(s).

So, technically, the title is correct, since the material chipinopo uses blocks sound from penetrating into the vehicle cabin by stiffening the vehicle structure to keep it from resonating. The stiffened structure reflects more sound energy away from the cabin, and dissipates sound energy the structure absorbs as heat.

 

I wouldn't worry about it.
I mean you had the whole thread up until I mentioned it and NOBODY was confused or didn't understand what you were doing or talking about.
None of these papers get handed in or are graded.

 

There's nothing confusing about the fact that terminology can sometimes be confusing and counter-intuitive... ...It just is. Besides. As you suggest, the point of digression begins where the comments become irrelevant. If you want to laugh at it, fine... ...It's funny... ...but there's no need to jump salty.

 

Without consulting the forums, on a whim I added some 157mil sound deadening / thermal insulation to mine this weekend. Like others, the effect was minimal. I could immediately tell that one tone was lessened on the drive in, but this seemed to make the tire road noise even worse to deal with.

I tend to believe that even if I only changed out the rear two tires for quieter ones, I would notice a vast improvement now.





That's not rain. That's sweat from a 'feels like' of over 100 degrees. This is why the job isn't perfect - I was doing my best to keep going out there.

 

Nice job.

As far as results go, it's easy to get discourage, but don't.

Any passengers in the rear cabin will notice a significant improvement. However, as you have observed, the driver and front passenger experiences only a slight reduction in noise, if any. This is because most of the road noise reaching the front cabin originates from the front wheel wells (see my previous comments in this thread).

Depending on what sound deadening you used, the most noticeable thing should hear is not a reduction in road noise, but a change in the perceived direction from which the road noise originates. Before sound deadening the cargo area, you should have noticed some noise coming from the rear cabin area and from the front wheel wells, plus wind noise from the doors. After sound deadening, you should no longer be able to discern road noise coming from the rear cabin area, but the over-all noise level will be reduced by only 1 or 2 dB (for the reasons stated above). It's not that the rear cabin noise is no longer there, but that the rear cabin noise has been reduced to a level where it is no longer perceived by the driver or front passenger. If it were possible to eliminate all noise except for the rear cabin noise, you probably would have noticed about a 50% reduction in noise resulting from your sound deadening efforts... ...not bad, considering that you only got a little more than half of the rear wheel well surfaces.

As you probably noticed, you cannot completely cover the rear wheel wells with interior sound deadening material without removing the rear seat and flooring material. This means additional sound deadening of the rear cabin can still be obtained by applying additional sound deadening the forward part of the rear wheel wells - either by removing the rear seat and carpet, or you can apply spray-on / paint-on sound deadening, like Second Skin Spectrum, as an undercoat to the wheel wells.

As you suggest, you can get additional reduction in road noise by installing quiet tires, such as the Bridgestone Turanza Quiettrack. However, as stated above, even if you completely eliminated road noise from the rear wheel well, the driver will still notice only a slight reduction in noise levels for the reasons mention above.

Keep in mind that the noise that you perceive originates from multiple locations, and the source of noise that has the most influence on your perception will always be the noise source that is the closest. You probably will start to notice a significant reduction in road noise only when you replace all four tires - even more so if you apply sound deadening to the forward cabin area as well.

 

Thank you.

It did isolate the noise, but I believed it isolated it to coming from primarily the rear tires. I completely believe that it is coming from many points, though. You wrote some nice follow-up posts on the effects.

I have seen pictures of people doing sound deadening inside the doors, and on the floors. I'd be willing to try that when the temps aren't over "feels like 110 degrees" like today has been.