Many people ask “What is an acoustic windshield?” This article aims to answer this question. An acoustic windshield is just like a regular windshield, with the added benefit of blocking outside sounds from coming into the cabin. Acoustic windshields look the same as regular windshields but the construction of them is quite different.
How exactly is an acoustic windshield constructed?
To understand the construction of acoustic windshields let’s first briefly look into how the regular windshield is made. Regular windshields work to protect people inside vehicles from the effects of the road. And to accomplish that, they need to be constructed to resist the elements of nature at high speeds.
At the basic level, they are constructed from two layers of shatter-resistant laminated glass. These two glass layers are held together by a compound called PolyVinyl Butyral or PVB in short form, which prevents them from breaking into smaller shards in case of an object hitting the windshield.
For the acoustic glass, this PVB compound is a little different. A special type of insulation is used which is called acoustic PVB compound that gets placed in between two laminated layers of glass.
How do acoustic windshields work?
As you can imagine, in passenger cars as well as most other types of vehicles, the biggest surface that hits the surrounding air is the windshield along with the front grill of the vehicle.
As much as we think air around us has a uniform density, it is far from it. Air pressure is different in air pockets as we move along the road. The faster we move faster this change occurs. Due to these changes, your windshield vibrates, causing the noise.
The PVB layer’s molecular structure is designed to convert these vibrations, not into sound, but another form of energy, namely heat. When the laminated glass in the front vibrates, the acoustic layer disrupts this vibration and prevents it from passing to the passenger cabin of the vehicle. Instead disburses it in the form of heat.
As a result, the sound waves which otherwise pass through the windshield, into the cabin get blocked. This special PVB compound is designed to filter out sound waves between 1500 and 5000-hertz frequencies, which is the main frequency range any regular person hears naturally.
Are there other benefits of having acoustic glass?
In addition to soundproofing vehicles, acoustic glass material provides a couple of additional benefits. The addition of an acoustic vinyl layer makes the windshield stronger and longer-lasting. The same vinyl layer also filters out the UV rays, which is another concern for all of us who have to sit in our cars for a long duration of time, exposed to the sunlight.
How do I know if I have an acoustic windshield or not?
A laminated acoustic windshield is not a very new concept Concept is around for quite a long time but in the last decade, most new cars, especially the higher-end models started to come equipped with acoustic windshields out of the factories.
In case you are in doubt about if you have an acoustic windshield or not, all you have to do is checking the windshield identification markings on your vehicle. Different manufacturers use different markings to identify acoustic windshields but, upon looking at the words or symbols, it is pretty easy to figure out if you have it or not. Some of the words or letters to identify acoustic windshields are:
- The word “Acoustic”
- The word “SoundScreen”(*)
- A logo in the shape of an ear with a curved arrow around it.
- The letter “A”
(*) SoundScreen is a trademark of Ford Motor Company
You can also check your car’s owner’s manual and look for any of these letters, strings, or symbols to figure out the type of your windshield. This might especially be a good idea, if you have purchased your vehicle second hand and not sure if it is replaced or not and if replaced, did the right OEM replacement part get installed per manufacturer specifications.
What are the additional benefits of having an acoustic windshield?
Acoustic glass does much more than blocking out noise. Let’s see what some of those benefits it can provide to you and your vehicle.
Reducing Ambient Noise
Of course, this is a no-brainer. The first and foremost reason to have such a windshield is to reduce the noise coming to the car cabin. As it was mentioned previously, the soundproofing technology found in the acoustic glass blocks the sounds between 1500 Hz and 5000 Hz frequency range. Most road noise, wind noise, or the noise generated by car engines fall in this range. Hence, it will be reduced by your acoustic windshield by 3 decibels.
The value 3 decibels may not sound like much but once you get used to the acoustic glass and switch to a different car without it, you can’t help but notice the difference how quieter it was. When you are sitting in traffic, your windshield can filter out that engine noise.
Also, one must not forget the wind noise while driving at a high speed. Just roll your window down to realize how loud it can be.
Additional strength for windshields and windows
The standard windshield manufacturers use a technology called safety glass, which is made to be hard to break. When an object hits the windshield, safety glass distributes the force of impact and instead of the glass dismantling it into smaller shards immediately. Safety glass tends to crack from the point of impact, spreading outwards in a spiderweb-like pattern.
This breakage pattern makes the difference between glass shrapnel hitting the passengers’ body vs. windshield staying in one piece. This is why it is called safety glass.
The design properties of acoustic windshields are very similar to that of safety glass. But the molecular structure of the acoustic vinyl layer adds extra strength. It still is may not totally shatterproof but added shatter resistance and durability is a highly desired benefit.
Also, the windshield is the most vulnerable part of a vehicle when it comes to break-in attempts. The additional strength of the acoustic windshield given by the acoustic vinyl layer will make it much harder to break the glass and get in. Therefore, it will become a deterrent against break-in attempts.
Most modern acoustic windshield manufacturers build their products with UV blocking technology because UV rays are harmful to the layer of acoustic vinyl. The fringe benefit of this technology is the reduction of incoming UV rays.
UV radiation is known to cause skin problems in people as well as being harmful to the vehicle’s interior surfaces. Therefore using an acoustic windshield is like hitting two birds with one stone.
Thinner and lighter windshields
Exterior noise is not a new problem. Manufacturers have been dealing with soundproofing issues for a long time.
The sound permeability of the glass is very high. To reduce the notoriously high sound transmission properties of glass, a lot of different methods have been employed in the past.
Thicker glass panels and double glazed glass windshields are a couple of them to mention. But the other downside of the glass is being too heavy. So, having two pieces of glass instead of one, to make the car soundproof, ends up adding to the weight of the car, which impacts the fuel economy negatively.
On the other hand, an acoustic glass used in today’s windshields uses two pieces of thinner laminated glass with sound blocking layers between them instead of double pane glass. Such construction yields a much thinner and lighter windshield than the windshields of the past.
The soundproofing capabilities of the acoustic glass made out of two layers of thinner glass are far better and lighter than its older counterparts, helping fuel economy.
Availability of acoustic windshields
If your car has been manufactured recently, maybe within the last decade or so, it is more than likely that the windshield repair and replacement companies have an acoustic windshield for your car. Most well-known windshield repair and replacement companies, carry these windshields.
When replacing a windshield of this type, ask for the OEM replacement part instead of an aftermarket variety, if you enjoy the quieter ride.
Although, if you own a late model Ford vehicle, your OEM replacement will be a SoundScreen windshield and due to licensing, it might be more expensive. Yet, there are other acoustic windshields available for your vehicle, without the SoundScreen inscription on them, which might be more cost-effective.
Aren’t there any pitfalls?
So far, we have talked about the advantages of acoustic windshields. They reduce outside noise, stop UV rays from coming in, make the windshield stronger and deter vehicle break-in attempts. Having one installed on your car sounds like a great idea.
Although, there is one drawback to acoustic windshields: the cost factor. The technology used in acoustic glass is rather new. Hence, the manufacturing costs have not come down enough to mass production pricing. Today, getting an acoustic windshield installed, costs the car owner $400 and upwards.
If something happens and it needs to be replaced, the same cost will be faced again by the car owner. Currently, no regular windshield rider clause in insurance policies covers the replacement of acoustic windshields. The full replacement cost must be paid by the vehicle’s owner.
Is the acoustic windshield enough?
Reducing noise is something important an acoustic windshield does but it is not the complete solution to soundproof your vehicle.
Your daily drive in regular traffic exposes you to an average of 75 decibels of noise. As previously mentioned, 3-decibel noise reduction by the acoustic windshield is a great help but for a quieter ride, some additional measures can be taken.
Additional soundproofing for your vehicle
There are additional steps that you can take for additional noise reduction in addition to installing an acoustic windshield. Let’s take a look at them.
Noise reduction in a car requires a holistic approach. Having a windshield of acoustic glass is just part of the process. It is an important part but it still is just one of the many things to consider.
All of your vehicle’s surroundings are subject to all sorts of sounds. it may be not as much as the windshield but noise levels are still high. Therefore, to reduce the noise level, all of the exposed surfaces of your vehicle should be soundproofed. And this can be as easy as opening up the interior coverings and lids and installing some kind of soundproof material.
The noise originating below the floor is another culprit. Vehicles have a lot of moving parts that generate a variety of sounds. As a matter of fact, most noise coming into the car originates from the undercarriage.
Nowadays, almost all vehicles come out of the dealerships with floor mats installed. And yes, a thick carpet can muffle sound to a certain extent but the regular floor mats are not there to reduce noise. On the other hand, there is a different type of floor mat called “damping floor mats”, which are specially designed to reduce the noise coming from the undercarriage.
Replace your tires
Tires are the only part of the vehicle that makes contact with the ground and the vibrations generated by this contact get transmitted into the car through all the solid parts, causing maybe the biggest contribution to the noise levels inside the vehicle.
Smaller the circumference of the tire or wider the contact surface, the noisier it gets in the cabin. Choosing narrower tires with larger diameters tends to reduce the noise they generate.
Also, before buying tires, check the manufacturer-provided sound ratings. Most manufacturers provide this information in the form of decibels generated while the tires are being tested. Going with lower decibel-producing tires will contribute to the reduction of noise.
Are acoustic windshields really worth it?
It really comes down to a judgment call here. Acoustic windshields most definitely have their advantages for reducing the noise outside, providing extra durability as well as added UV protection compared to their regular counterparts.
On the other hand, they are not as cheap as a regular windshield and the insurance coverage is nearly nonexistent due to the cost factor.