Although vehicle interiors are generally quite good at blocking out sound, there has been a surge in popularity for acoustic windshields in recent years. Since then I’ve regularly had people asking me how acoustic windshields work, and, more importantly, whether they’re worth the investment.
Acoustic windshields are windshields having an extra layer of soundproofing material (such as vinyl) between the layers of glass. This provides the windshield with noise damping properties, which results in a quieter vehicle interior.
While this is a basic explanation of how acoustic windshields work, it’s worth understanding the technology in more detail. In this article I look at the science behind acoustic windshields, along with the main pros and cons of installing one in your vehicle.
How do acoustic windshields work?
A normal vehicle windshield is made of several layers of laminated safety glass. As many may already know, safety glass is designed to not shatter when broken, making it a good choice for vehicles.
In addition to 2 outer layers of safety glass, there will also be an internal layer of material that provides structural integrity to the windshield. Typically this will be made from either polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA). For the purposes of this article, we’ll be talking about PVB.
Laminated safety glass already does a fairly good job of insulating the vehicle interior from sound, as it’s generally thicker than normal glass. However, as many soundproofers will know, glass is one of the weaker materials in a soundproofing project. Therefore there’s always room for improvement.
When it comes to an acoustic windshield, an extra layer of acoustic PVB is added into the middle of the lamination. This PVB is designed with acoustic dampening properties, and is usually intended to work against frequencies between 1500 and 5000 Hz.
Normal vs laminated vs acoustic glass
While the main purpose of an acoustic windshield is to reduce the level of noise experienced inside the vehicle, they also help with improving overall comfort while driving. For example, acoustic windshields can also help to reduce heat loss, vibration level, and air resistance.
In the past, the standard way to make a windshield more insulated was to make it thicker. This has obvious drawbacks when it comes to vehicle production, as most manufacturers are always looking for ways to reduce the overall weight of the vehicle. Luckily acoustic windshields manage this quite well.
A good comparison would be if you were soundproofing a wall and you decided to add several more layers of normal drywall. While this would make a difference, you’ll end up with a thick wall and minimal noise reduction. A better solution would be to use a specialist product, such as mass loaded vinyl, which does a better job and uses less space.
Several studies have been done on the performance of acoustic windshields compared to normal versions. These studies found that, on average, acoustic windshields reduce noise pollution inside the vehicle by 2-3 decibels.
Although this doesn’t sound like a massive reduction in noise, it’s enough to make a noticeable difference inside the vehicle. Similarly, the benefits of an acoustic windshield do extend beyond just reducing noise levels, as we’ll see below.
How to tell if you have an acoustic windshield
Acoustic windshield technology has been growing in popularity in recent years as manufacturers realize there’s a demand for it. For this reason, it’s worth checking if you already have an acoustic windshield fitted in your car, as some models come with it as standard.
Generally speaking, there should be an indicator in the front driver’s side corner of your windshield. This will most likely be an “A” or the word “acoustic”, or possibly a picture of an ear. Alternatively, some manufacturers use a brand called SoundScreen, which would also be stated on the windshield.
If you can’t see any obvious indication on your windshield, then check the owner’s manual before you go any further. It might say in there as part of your windshield care, or you could speak to the dealer who sold you the car.
The benefits of acoustic windshields
As we’ve established, acoustic windshields seem to offer a range of benefits for the driver. However it’s worth looking into these benefits in a bit more detail to understand whether it’s worth making the plunge.
1. Improved noise reduction
This is of course the most obvious benefit and the one already stated here. Reducing internal noise levels by 3 decibels might not sound like much, but you will notice a difference when driving the car. Much noise pollution simply comes from the wind, and this will definitely be reduced.
Similarly, having a frequency range of 1500 to 5000 Hz covers plenty of different everyday sounds that you’ll experience when driving. These include things like wind and the noise of other cars, while still allowing you to hear important sounds such as other cars’ horns.
Acoustic behavior of laminates and float glass (source)
2. Reduced chance of vehicle theft
One of the most common ways for someone to gain access to a vehicle is to smash the windshield. Gone are the days when a door lock could be easily picked, which has resulted in thieves taking advantage of a vehicle’s structural weakness, the windshield.
Although normal safety glass is designed not to shatter, it can still be broken with a bit of force. If someone is looking to steal something from your vehicle, a simple windshield smash will usually get the job done.
Surprisingly, a benefit of an acoustic windshield is that it makes it harder for someone to gain entry. This is because the acoustic PVB layer is very sturdy, which makes the glass much harder to break.
While an impact would still crack the glass, the acoustic PVB will prevent it from smashing or shattering. Although this might not necessarily stop people from trying to gain entry to your vehicle, it’ll make it harder, hopefully meaning they’ll give up.
3. A thinner windshield means better fuel efficiency
As you may already know, the reason manufacturers are always looking to reduce the weight of a vehicle is to improve fuel efficiency. A lighter vehicle needs less fuel to move itself, which is simple physics.
Using an acoustic windshield is therefore much more efficient because it saves you having to use a thick piece of glass. The PVB layer provides better sound blocking while also being lighter.
A good comparison is the surge in popularity of carbon fiber body parts, rather than traditional metal parts. This makes the vehicle much lighter while not sacrificing structural integrity. Although petrol vehicles are mostly on their way out, this same logic will apply to electric vehicles in the future.
4. Improves structural integrity of the windshield
This benefit has been mentioned already in a different context, but you can never be too conscious of road safety. Although normal laminated safety glass is designed to not shatter, it can still break. The difference is that normal glass will break into shards, whereas safety glass breaks into tiny pieces that aren’t as sharp.
Realistically, any broken windshield is a safety hazard in a collision. Small pieces of broken glass can cause damage; although you’re at a much lower risk than if you had normal glass in your windshield. This article explains in more detail the different ways glass breaks.
Acoustic windshields, however, add another layer of structural integrity to the glass, which makes it much harder to smash in the first place. It would require a very heavy collision to smash an acoustic windshield.
While this doesn’t give you an excuse to drive more recklessly, having peace of mind in a generally safer vehicle does make a difference when out on the road. Similarly, if the windshield does break, the PVB layer helps it remain in one piece rather than falling into the vehicle.
5. Improved UV resistance
Another almost hidden benefit of an acoustic windshield is that the PVB layer also usually has UV reducing properties, which is helpful for anyone who does a lot of driving in the sun.
Normal windshields often have a level of UV blocking already, but acoustic windshields have more. Not only does this make it safer for you to be in the vehicle, but it also prevents the sun from bleaching the vehicle’s interior, which is always helpful.
While the benefits of reducing UV rays might seem obvious, normal glass can actually magnify the intensity of the sun’s rays, leading to higher rates of sunburn and other skin problems.
Therefore including UV blocking technology in a vehicle’s windshield makes it much safer for you to be in the vehicle. Considering driving is when many of us are exposed to the sun without a choice, reducing UV levels inside the vehicle is an obvious benefit.
The cons of an acoustic windshield
You might think that acoustic windshields are the perfect improvement to any vehicle, and realistically this isn’t far from the truth. However, there are some downsides that you should consider before you jump into buying one.
1. Cost
The biggest drawback of an acoustic windshield is the cost. As the technology is still fairly new, there’s often a large price tag attached to reflect this. For example, a manufacturer approved acoustic windshield will be at least $400, although this will depend on the vehicle.
It’s worth bearing in mind that, like any other technology, the price will only go down as it becomes easier to manufacture. The price of acoustic windshields has already dropped considerably since they were introduced to the market, so if you can’t afford one now then wait a while for them to drop more.
2. It might not be covered by windshield cover
It’s fairly typical nowadays that vehicle insurance will offer some kind of windshield cover in the event of a chip or crack. Rather than paying the full cost, this cover allows you to only contribute a small amount.
However, an acoustic windshield may not be covered under this, as it’ll depend on the extent of the damage. Luckily this is a fairly easy thing to confirm, and you’ll just need to speak to your insurance provider first.
An alternative is to see if you can get windshield cover from the manufacturer or provider instead. This might not be the biggest drawback in the world, but it’s definitely worth looking into before you make the upgrade.
Are acoustic windshields worth it?
So now that we’ve dissected the pros and cons of acoustic windshields, along with looking in detail at how they work, it’s time to ask the most important question: are they worth it?
In short, acoustic windshields are definitely worth the investment if you want a quieter and more comfortable driving experience. You don’t have to be a soundproofing aficionado to want one, as I imagine everyone would prefer to drive in comfort.
An acoustic windshield is an obvious advantage if your vehicle has a loud engine or if you’re looking to improve its overall fuel efficiency. However, these don’t need to be the only situations in which it proves beneficial, as almost everyone will notice an improvement.
However, if you’re looking for a complete soundproofing experience inside your vehicle, then consider installing some sound deadening mats too. A good brand is Dynamat, whose products are designed specifically for use in vehicles. They help to reduce vibration and also insulate against engine heat.
Some final thoughts
Overall, acoustic windshields will make a noticeable difference to noise levels inside your vehicle. Along with this, they also improve safety and fuel efficiency, which are all good things, right?
The main thing to remember is that this will be a financial investment, as acoustic windshields don’t come cheap. And, as with any other product, the more advanced you go, the more expensive things get.
Regardless, it’s worth doing a bit of research into your options for your specific vehicle. Speak to your dealer or manufacturer to see what they can advise, but also do plenty of research online before making a purchase.