How to Cut Road Noise in Our Corvettes

Everybody in the world knows modern Corvettes are the best Supercar for the money, absolutely!

But, they tend to be a bit too loud for most of us owners so I have worked out what it takes to make them far more comfortable with reduced road noise and cabin heat (they are known to be quite warm inside as well)

A great by product of this effort is improved audio systems response whether or not you have upgraded the sound system. Conversely, doing this for audio takes care of road noise and thermal issues, they go hand in hand.

A major part of why these cars are so incredible performers is the low weight so we must take that into account when deadening. By adding only add what is absolutely needed, wihin each individuals particular requirements, minimalist approach which is mostly the track oriented owners, middle ground, what most chose or going all out, but still not a huge added amount of weight we can make the car much more comfortable with little sacrifice in performance.

In most vehicles the doors are the number one place to start and very important in the Vette but the rear of the car is even critical.

C6 Example, C5 are very similar, earlier Corvettes require a few different methods but the end results are the same.

The large middle area of the rear floor is very flexible and thus very resonate so it needs a some mass loading and stiffening provided by a mat based product like BXT II. We do not have use full coverage in most vehicles but in the Vette at bit more than most cars, at least 70% for the mid-level install. The edges are pretty stiff and can be left without being matted.

This shows a C6 tub with the going all out install with more coverage of the BXT II, most installs will stop short of going out to the edges, etc…(see note at the end, need a free deadening install? We need better pictures;)

c6tubBXTII

Next I line the wheel well and 40-50% of the sides and rear wall, focused on the middle of those areas then cover every square inch possible in the Ensolite foam.

Ensolitefloor

Ensolite is very low in weight, less than ½ lb per sq yard, yet is a superb thermal and acoustical barrier developed for the space program and extensively in the aircraft industry. Ensolite works mainly in a higher frequency range than mat type products, decouples acoustical energy, the rough surface breaks up waves that hit it and helps prevent panels from resonating that contact it. The combination of adding mas and the foam provides a dramatic increase in performance over using just one type of material, nearly doubling the results.

We can next consider the area behind the seats, it is rather thin sheetmetal and prone to resonance so a bit of mat and foam can do wonders yet not a great deal of effort or material needed. Just focus on the middle areas, 50% coverage with the mat, full coverage with the Enoslite, done!

Doors, these are tricky in the Vette to keep weight down and deaden them well. I recommend adding some thin wall aluminum channel available at most any hardware store, double face tape to hold it in place and then mat up and onto the edges. The channels I use are 3/8×1/2X3/8x24”, two per door. Less mat is needed to get the desired deadening, less weight added!

c6doorchannel

I then add more mat to the exterior skin of the doors, around 40% coverage, in the middle and resonate prone areas only.

BIG access holes in these doors allows a great deal of road noise into the car, Alumalite filler plates weigh just 11 oz yet are very stiff and seal up the area which also improves mid bass speaker response.

More Ensolite, add a layer as shown, then a patch behind speaker. An 8x8” area inside the door is all you want to use as this material is so effective it literally kills the midbass response if you add to much!

Cover the door with Ensolite as shown.

c6doorfoam

Upgrading the stock speakers, I hope so as we can do much better, Alumalite baffles weigh just 4 oz and are not effected by moisture as other lessor materials often can be. The ensolite wrap seals the honeycomb edges to keep moisture out and act as the speaker gasket.

c6speakerbaffle

Door panels, many parts, many potential resonance issues. Near the speaker grill on the back of the door panel add a few patches of mat then Ensolite all around it, leaving the grill open of course. This will help break up any audio energy that escapes to the sides and reduce distortion and door panel resonance.

That covers the middle level of deadening which is the sweet spot for the majority of us Vette owners.

Minimal installs will just use less mat everywhere, carefully focused on the most resonate prone areas, if it flexes, it will resonate in the frequency range we are concerned with reducing.

Maximum installs, more coverage with the mat, tunnel and floors done as well.

Added weight? Minimal install, approx. 10 lbs, mid level, 18-20, all out, 26-28 lbs.

Some pictures shown are not of great quality so we need a volunteer to come to Utah and get their car done right, working together, on us, so we can take some better photos for the official deadening guide we are producing.

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During the next segment we are going to cover the use of compact, very low weight, superior sounding high power amplifiers, neo magnet mids and tweeters and low weight subwoofer enclosures as well as setup to get the best realistic sound stage.

The bottom line is:

We can have our supercars with reduced road noise, greatly improved stock or better yet upgraded audio systems and not add a great deal of weight, we truly can have it all if we do it right and that is why I do what I do for our sweet cars and my fellow enthusiasts.

www.raamaudio.com

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