Sound Deadening Material Independent Testing Data

First up, and the product that will act as the reference for the rest of the comparisons, ResoNix Mega CLD Squares. As you can see in the before/after measurement, the test panels resonance has a 19.75dB reduction with the application of ResoNix Mega CLD Squares, and is nearly eliminated entirely. As mentioned earlier, this is going to be our reference. So from here on out, if another product has a 3db difference from ResoNix Mega CLD Squares, performance would increase or decrease by a factor of 2x. If it had a 6db difference, a performance difference of 4x. If there is a 9db difference, that difference would be 8x. 12db difference, 16x difference, and so on. Remember, the db scale is logarithmic.

ResoNix Mega CLD Squares vs. Original ResoNix CLD Squares performance

Up against them first, our original product, the ResoNix CLD Squares. This is our original CLD since day 1, and has remained the same ever since. It was the best product on the market when it was released, and is still only bested by our Mega CLD Squares.

As you can see in the before/after measurement comparing the original ResoNix CLD Squares to Mega, the original has a panel resonance reduction of 17db. This 2.75dB increase in resonance reduction ResoNix Mega CLD Squares puts it as 1.9 times better than the original ResoNix CLD Squares. The Mega CLD Squares currently come in at $14.25 per square foot (a larger package offering coming soon will put this even lower), and the original CLD Squares come in at $8.50. This allows the original CLD Squares to have an equal performance value of $16.15 vs the ResoNix Mega CLD Squares. Looks like our newer ResoNix Mega CLD Squares is not only a better performer than our original CLD Squares & the rest of the products out there, but also a better value than all of them as well.

ResoNix Mega CLD Squares sound deadener performance vs. other popular brands

The ResoNix Mega CLD Squares stand out as the highest performing sound deadener in the market. They are 1.9 times more effective than the original ResoNix CLD Squares, offering an additional 2.75dB reduction in resonance on the given test panel. Compared to Dynamat Extreme, which reduced resonance by 11.75dB less, ResoNix Mega CLD Squares is 15 times more effective. Against Soundskins Pro 3-in-1, which showed a 10.75dB lesser reduction in resonance, ResoNix Mega CLD Squares proves to be 12 times more effective than the Soundskins Pro 3-in-1 sound deadener.

NOTE: This product was tested when it was offered in 90-mil thickness. It is now offered in only 70-mil thickness. The test results and data shown here are no longer viable for the product that they currently sell.

Another random product that I haven’t heard of that Chris’s managed to get his hands on to test. Looking into it, it looked oddly familiar. I did some digging and found out that this seems to be from the same manufacturer of KnuKonceptz sound deadener, which has a bad history of melting product, so buyer beware. Anyways, on to the testing results.

Also like Knu Konceptz, while having very poor resistance to heat and melting, it has decent resonance control. It is actually the best product for resonance reduction at room temperature behind ResoNix Mega CLD Squares and original CLD Squares. It reduced the resonance peak of the test panel by 13.75db, which puts ResoNix Mega CLD Squares as 4x  better in resonance control performance. Coming in at $5.14 per square foot, it puts its price to performance ratio at $20.56 versus ResoNix Mega CLD Squares $14.25. It is one of the better values of the bunch when it comes to resonance control, but like Knu Konceptz, I am very skeptical for how it will hold up in an automotive environment long term, and how that resonance control will perform once it is above room temperature. Once again, I cannot wait to see Chris’s results from heat testing.

Harmony vs. other popular brands

Harmany sound deadener is outperformed by ResoNix Mega CLD Squares, with ResoNix reducing resonance by an additional 6dB (making it 4  times more effective), Harmony excels against other competitors. It outperforms Dynamat Extreme significantly, reducing resonance by 5.7dB more, making it 3.75 times better. Compared to Soundskins 3-in-1, Harmany is more effective, achieving a 4.75dB greater reduction in resonance, which makes it 3 times better. Against Kilmat 80-mil, Harmany shows even greater superiority, reducing resonance by 6.5dB more, making it 4.5 times more effective.

STP Gold is the same product, just a thicker version, of STP Silver. STP Gold reduced the test panel resonance by 12.5db, making ResoNix Mega CLD Squares 5.3x more effective with its 19.75dB reduction in the test panels resonance peak. STP Gold is no longer available in the US since it is Russian made and there is currently a ban on importing Russian products, but it previously had a price of $4.13 per square foot, which gives it a price to performance of $21.89 vs ResoNix CLD Squares $14.75. Considering it is the same butyl formula as STP Silver and my experiences with that, I would not recommend it (it melted into a Vaseline-like consistency in my old car when I used it before I started ResoNix)

STP Gold vs. other popular brands

STP Gold sound deadener performs a bit better than the STP Silver, but still varies between other popular brands.

ResoNix Mega CLD Squares, however, outperforms it by reducing resonance by an additional 7.5dB, making ResoNix 5.3 times more effective. In contrast, STP Gold excels against Dynamat Extreme, outperforming it by 4.5db and thus being 2.8 times better. When compared to Soundskins, STP Gold is more effective, reducing resonance by 3.5dB more, making it 2.25 times better. Against Kilmat 80mil, STP Gold shows even more superiority, achieving a 5.25dB greater reduction in resonance, which makes it 3.4 times more effective.

Next up is NVX 90mil. In both the original and more recent testing, it reduced the resonance peak by 11.5db. Not bad. Let’s see how it compares in value to ResoNix Mega CLD Squares. We were able to find NVX 90mil for as low as $3.96 per square foot when buying a bulk pack. Remember, ResoNix Mega CLD Squares reduces the test panel’s resonance by 19.75dB. Based on this, we can calculate that ResoNix is 6.75x as effective as NVX. This means you would need to, in theory, apply 6.75 times as much NVX 90mil to the test panel to get the same reduction as a given piece of ResoNix CLD Squares. 

Taking that 6.75x multiplier to their $3.96 per square foot price, we can calculate its price to performance would be $26.75, vs. ResoNix Mega’s $14.75. We have something close, but when using this product, you would then have to go through the additional work of applying 6.75x as much product vs. ResoNix Mega CLD Squares to get the same performance, or, be okay with a lower performance ceiling.

NVX vs. other popular brands​

NVX Sound Deadener performs variably compared to other popular sound deadening products. It is less effective than ResoNix Mega CLD Squares, which reduced resonance by 8.25dB more, making it 6.75 times better for resonance reduction. However, NVX outperforms Dynamat Extreme by reducing resonance 3.5dB more, making it 2.25 times better, although Dynamat Extreme has superior heat resistance. NVX is also more effective than Kilmat 80-mil, offering a 4.25dB additional reduction in resonance (2.7 times better). When compared to Soundskins 3-in-1, NVX performs 1.8 times better by reducing resonance by an extra 2.5dB.

NOTE: This product used to be 90-mil in thickness and was so at the time of testing. They now only offer it in 55-mil and 70-mil thicknesses. The test results and data shown below are no longer viable for the product that they currently offer. There is currently no data on the new, thinner offerings. 

Next up, the king of consumerism, Amazon Basics. A few years ago, Amazon decided to get their skin in the sound deadening game. Many are weary, as we know it is most likely that they didn’t have a smidge of care and just found the cheapest thing they can put their name in mass volume on and distribute worldwide, as with all things they put under the Amazon Basics name. So let’s see what the data says.

Up next is Second Skin Damplifier Pro. This is regarded as one of the better CLD’s on the market, and they have very strong marketing materials claiming as such. Since we know marketing means squat when it actually comes to the performance of any product, let’s see what the data says. In Chris’s testing, Second Skin Damplifier Pro reduced the test panels resonance peak by 11dB. ResoNix Mega CLD Squares reduce the resonance peak of the test enclosure by 19.75dB. This puts our Mega CLD Squares performing 6.7x better than the Damplifier Pro. This puts it about middle of the pack in terms of resonance control performance. Damplifier Pro also costs $7.95 per square foot, making its equivalent price to performance $53.27 in comparison to ResoNix Mega CLD Squares $14.25 per square foot. Respectable company, good people, but the performance claims just are nowhere near where they claim. Sorry guys. 

Second Skin Damplifier Pro vs. other popular brands

Second Skin Damplifier Pro sound deadener demonstrates varied performance when compared to other popular sound deadening products. It is much less effective than ResoNix Mega CLD Squares, which reduced resonance by an additional 8.25dB, making ResoNix 6.7 times better. However, Second Skin Damplifier Pro outperforms Dynamat Extreme, reducing resonance by a further 3.5dB, making it 2.25 times more effective. Against Kilmat 80-mil, it is significantly more effective, with a 4.25dB additional reduction in resonance, translating to 2.7 times better performance. When compared to Soundskins 3-in-1 sound deadener, Second Skin Damplifier Pro is more effective, reducing resonance by an additional 2.5dB, making it 1.8 times better.

Canopus is apparently a new sound deadener brand on the market that is made in asia. How long they have been around for exactly, I can’t say as this test was the first time I had heard of them. Looking into them, I really can’t find much info. So anyways, on to its testing results. Canopus reduced the resonance peak of the test panel by 11db, so not terrible, but definitely not great. ResoNix Mega CLD Squares come in at 7.5x as effective with its 19.75db resonance reduction versus the 11dB reduction of the Canopus. The pricing I managed to find for Canopus puts it at $4.40 per square foot, which gives it a price to performance ratio of $20.63, vs ResoNix $14.25. Once again, I am curious to see its heat testing results as many of these asia produced brands have so few real world, long term reviews since they are so new.

Canopus vs. other popular brands

Canopus sound deadener shows varying effectiveness when compared to other popular brands. It is outperformed by ResoNix Mega CLD Squares, with ResoNix reducing resonance by an additional 8.5dB, making ResoNix 7.5 times more effective. However, Canopus outperforms Dynamat Extreme, achieving a greater resonance reduction of 3dB, making it 2 times better in performance. Compared to Soundskins, Canopus is more effective, reducing resonance by 2dB more, which makes it 1.7 times better. Against Kilmat 80mil, Canopus shows superior performance, reducing resonance by 3.75dB more, making it 2.4 times more effective.

Another product coming from Asia that I haven’t personally heard of, so let’s dive into the data. Koxuyim reduced the test panels resonance peak by 11db, which is about average, but puts ResoNix Mega CLD Squares as 7.5x better with its 19.75dB reduction in the test panels resonance peak. 

Koxuyim came in at $2.33 per square foot when it was still available, which gives it a price to performance ratio of $17.48 vs ResoNix Mega $14.25. Another close contender for value, but once again we have no idea how well it holds up to heat and will have to wait until Chris heat tests it, and it’s also no longer available last we checked.

Hushmat is another American-made CLD that is known in the car audio industry. This is something I have had my hands on in the past, and honestly, I really expected this to do pretty poorly. Well, According to the results, I wasn’t exactly wrong, but it did better than I expected (goes to show that anyones subjective interpretation can be off from the truth, and it also shows how much these differences in testing really are in real use applications). It did about average, which was honestly much better than I expected. It came in at 10.25db of panel resonance reduction. This puts ResoNix CLD Mega Squares at 9x better with its 19.75dB resonance reduction in the test panel.

Hushmat comes in at $6.94 per square foot, which gives it a price to performance ratio of $62.46 versus ResoNix Mega $14.25. While it obviously isn’t a great performer or a great value, I am still wondering how it did as well as it did considering my subjective experiences with it. 

Hushmat vs. other popular brands

Hushmat sound deadener displays varied effectiveness compared to other popular sound deadening products. It is significantly outperformed by ResoNix Mega CLD Squares, with ResoNix reducing resonance by an additional 9.5dB, making it 9 times more effective. However, Hushmat exceeds the performance of Dynamat Extreme, reducing resonance by 2.25dB more, which makes it 1.7 times more effective. Compared to Soundskins, Hushmat is also more effective, with a 1.25dB greater reduction in resonance, making it 1.35 times better. Against Kilmat 80-mil, Hushmat shows superior performance, reducing resonance by 3dB more, making it 2 times more effective. 

STP Aero is marketed as the even bigger and badder brother of STP Gold. Well, data shows otherwise. STP Aero reduced the test panels resonance peak by 10.25db, so its “little” brother, STP Gold, is actually a better performer with a 12.5dB reduction. Relative to ResoNix, our Mega CLD Squares proves to be 9x more effective than the STP Aero. STP Aero is no longer available in the US as it is a Russian manufactured product, but it had a price per square foot of $6.00 per square foot. Doing the price to performance calculation, turns out to be $54.00 relative to ResoNix Mega CLD Squares $14.25. Average performer, poor value, and no longer made due to import restrictions on Russian goods. 

STP Aero Sound Deadener Performance vs Other Popular Brands

STP Aero sound deadener goes a bit backwards in performance and is less effective than its STP Gold counterpart. 

It is also outperformed by ResoNix Mega CLD Squares, with ResoNix reducing resonance by an additional 9.5dB, making our Mega CLD Squares 9 times more effective than STP Aero. However, STP Aero exceeds the performance of Dynamat Extreme, reducing resonance by 2.25db more, which makes it 1.7 times better. Compared to Soundskins, STP Aero is also more effective, with a 1.25dB greater reduction in resonance, making it 1.35 times better. When pitted against Kilmat 80-mil, STP Aero shows superior performance, reducing resonance by 3dB more, making it 2 times more effective.

Up next is 3M’s EDM. This is a new product that is different from traditional Butyl/Aluminum CLD’s. Its purpose is to be extremely light yet practical. The downside is, you pay a premium for the lightweight for average performance. We are leaving the ResoNix Mega CLD measurement visible to use as a visual gauge, but remember, another product being visually halfway in between the “before” peak and the ResoNix measurement does not mean the other product is half as good. Remember, every 3db difference is 2x the energy. In the latest testing, our Mega CLD Squares reduce the test panel by 19.75dB, while the 3M EDM1029 reduces it by 10.25dB, making ResoNix 9x as effective per square foot.

We were able to find this product for as low as $9.02 per square foot. We can calculate that, in theory, you would need to spend $82.08 to get enough of the 3M product to achieve the same result as the $14.25, 1 Square foot of ResoNix Mega CLD Squares. In the original testing, this is the worst value product in the entire test regarding resonance reduction. In the new testing that features more products, it still doesn’t fare well, but there are some that are grossly more overpriced.

3M EDM vs. other popular brands

The 3M EDM Sound Deadener performs variably compared to other popular sound deadening products. It is significantly outperformed by ResoNix Mega CLD Squares, which reduced resonance by 9.5dB more, making ResoNix 9 times more effective. However, 3M EDM outperforms Dynamat Extreme, with a 2.25db greater reduction in resonance, making it 1.7 times better. It also shows better performance than Kilmat 80-mil, achieving a 3dB additional drop in resonance, resulting in 2 times better effectiveness. Additionally, 3M EDM is 1.35 times more effective than Soundskins, with an extra 1.25dB reduction in resonance.

Moving on, we have the original king of Amazon sales, Noico 80-mil. In its testing, Noico shows to reduce the test panels resonance peak by 10dB. Comparing it to ResoNix Mega CLD Squares which lowers the resonance peak by 19.75dB, another 9.75dB further than Noico. This equates to ResoNix being 9.5x more effective at reducing resonance in a given panel.

Noico can be found for $6.11 per square foot (prices drastically went up since the war in Ukraine). Price to performance vs. ResoNix CLD Squares, you would spend $58.05 to get enough Noico to, in theory, be as effective as ResoNix. This is also not a good value, especially when you consider the extra work required to apply all of that additional product to reach any level of performance somewhat close to ResoNix. 

Noico vs. other popular brands

Noico Sound Deadener shows mixed performance compared to other popular sound deadeners. It is significantly less effective than ResoNix Mega CLD Squares, with ResoNix performing 9.5 times better due to its 19.75dB drop vs Noico’s 10dB drop. However, Noico outperforms Kilmat 80-mil by reducing resonance by an additional 2.25dB, making it 1.7 times better. It also slightly exceeds Soundskins 3-in-1 by reducing resonance by 0.5dB more, translating to a 1.15 times better performance. Against Dynamat Extreme and the similar performing Soundskins sound deadener, Noico has a slight edge with 1.5dB more reduction in resonance, making it 1.4 times better. However, while Dynamat Extreme is better known than Noico for its reliability in hot climates, as there are reports of Noico failing under high temperatures.

Another random constrained layer damper from Amazon it seems, Smartmat 90-mil seems really fancy looking and looks like a good budget to those who aren't as educated on the subject.

It turns out its resonance control performance is average at best. Smartmat reduced the test panels resonance peak by 9.75dB, which makes the 19.75dB reduction by ResoNix Mega CLD Squares 10x as effective. Smartmat 90-mil comes in at $2.43 per square foot, which gives it a price to performance equivalence of $24.30 vs. ResoNix Mega CLD Squares $14.25. This is another product that I am very curious to see how it does in long-term heat testing. 

Smartmat 90mil vs. other popular brands

Smartmat 90-mil sound deadener shows lower performance compared to better popular brands, but does better than some of the low performing but popular products. ResoNix Mega CLD Squares greatly outperforms it by reducing resonance by an additional 10dB, making ResoNix 10 times more effective. Dynamat Extreme on the other hand performs worse than Smartmat 90-mil, with a 1.75dB reduction in resonance, making Smartmat 90-mil about 1.5 times better. Soundskins also falls under Smartmat 90-mil as well, with a 0.75dB lower reduction in resonance, making Smartmat 90-mil 1.2 times more effective. Kilmat 80mil also shows lower performance than Smartmat 90-mil, reducing resonance by 2dB Less, making it 1.7 times more effective than Kilmat 80mil.

Next, we have Roadstage Audio, which is a “3-in-1” product that is now no longer sold. It is  butyl, foil, and foam all in one package. I suspect it was coming from the exact same factory that is making the new version of Soundskins “3-in-1” product. Lets see how effective it is at reducing panel resonance. As you can see on the graphs, Roadstage reduced the resonance peak by 8.5db, making it nearly identical in performance as the aforementioned Soundskins product. My money is on that they are the same thing. ResoNix Mega CLD Squares 19.75dB reduction allows us to calculate that ResoNix is 13.5x more effective per given amount compared to Roadstage Audio. I cannot find a website for Roadstage, let alone pricing, so we have no way to calculate the price to performance ratio, especially now that they don’t exist. That said, I have a hard time believing that was cheap enough (especially considering it’s a 3-in-1 product) to be anywhere in the ballpark of the value of ResoNix CLD Squares.

Roadstage vs. other popular brands

So how does Roadstage Audio Sound Deadener perform against the more popular sound deadener brands? Roadstage Audio Sound Deadener heavily underperforms compared to ResoNix Mega CLD Squares, with ResoNix achieving 11.25dB more in resonance reduction making it 13.5 times better for resonance reduction. Roadstage marginally outperforms Kilmat 80-mil by 1.25dB, making it 1.35 times better.

It also slightly exceeds Dynamat Extreme by 0.5dB, translating to a 1.15 times better performance. However, Soundskins, made in the same factory as Roadstage, performs slightly better than Roadstage by 0.5dB, ranking it 1.15 times better. This performance variation could be due to minor differences in material thickness or variations in manufacturing batches. 

Next up is Boom Mat. Honestly, I’m not really sure what to say about them as I havent paid much attention to them at all and have never seen their products in person. So, lets dive into the test results.

For resonance reduction, Boom Mat reduced the resonance peak of the test panel by 8.25db, so this is a pretty low performer. ResoNix Mega CLD Squares being at 19.75dB resonance reduction puts it as 14.25x better than Boom Mat. This gives Boom Mat, which comes in at $8.40 per square foot, a price to performance ratio of $100.18. So not only is it a low performer, it is also a poor value. 

Boommat vs. other popular brands 

Boommat sound deadener has mixed results when compared to other popular brands. It is significantly outperformed by ResoNix Mega CLD Squares, which reduced resonance by an additional 11.5dB, making ResoNix 14.25 times more effective. Against Dynamat Extreme, Boommat performs almost equally, with Dynamat reducing resonance just slightly less by 0.25dB. However, Soundskins is more effective than Boommat, reducing resonance by 0.75dB more, making Soundskins 1.2 times better. When compared to Kilmat 80-mil, Boommat shows better performance, reducing resonance by an additional 1dB, which makes it 1.25 times more effective than Kilmat 80-mil.

The last of the bunch that Chris tested was the Siless 80mil and 50mil. These are also becoming very popular options in the car audio, van build-outd, and general automotive worlds. And like many of these other products, it’s due to their cheap price. Well, yes it may be cheap, but does it actually get you your moneys worth? Let’s see. 

The Siless 80mil reduced the resonance peak of the test panel by 8.25db, which is definitely on the low side of the bunch. This makes the 19.75dB reduction by ResoNix Mega CLD Squares 14.25x more effective. Siless 80mil has a price of $2.22 per square foot, and doing the math to give us its price to performance vs our Mega CLD Squares, it comes out at $ 31.64 per square foot. So, while it may be cheap, it is definitely not a good value, and is definitely a very poor performer. Considering this is 80mil thick butyl it makes me wonder how much this product is loaded with fillers, and if the aluminum is even aluminum (some lower end products have used mylar in the past). Who knows, but it is a poor performer. 

Note: We have not had our hands on this product personally, but we have had many customers tell us that it smells like asphalt. Beware.

Siless 80mil vs. other popular brands 

Siless 80mil sound deadener demonstrates varying performance levels compared to other popular sound deadening products. It is significantly outperformed by ResoNix Mega CLD Squares, with ResoNix reducing resonance by an additional 11.5dB, making our Mega CLD Squares 14.25 times more effective. However, Siless 80-mil slightly outperforms Dynamat Extreme, with a 0.25dB greater reduction in resonance, making it 1.05 times better. It is less effective than Soundskins, which reduces resonance by 0.75dB more, making Soundskins 1.2 times better. Against Kilmat 80-mil, Siless 80-mil shows better performance, reducing resonance by 1dB more, making it 1.25 times more effective.

Next up is the Kleenex of sound deadener, Dynamat Extreme. This is the most popular product for aftermarket automotive use worldwide, and they have been around for decades. They were probably even the first proper constrained layer damper available in the aftermarket industry. But just because they were the first, does it mean that they are the best? Does it mean that they even have a product worth using in todays world?

Looking at the measurements from the original test, Dynamat Extreme drops the peak in the resonant frequency only 8db. This is an extremely disappointing level of performance for the “Kleenex” of the industry. ResoNix Mega CLD Squares being at a 19.75dB reduction in the test panel, is a whopping 15x more effective than Dynamat Extreme per given amount (11.75dB more equates to 15x the amount of energy). So, for every square foot of ResoNix Mega CLD Squares, you would need 15 square feet of Dynamat Extreme to, in theory, yield the same result.

At the time of writing this, we were able to find Dynamat Extreme online for as low a $6.67 per square foot. This generates a price-to-performance of $100.05 vs. ResoNix Mega’s $14.25. In theory, to get the same end result as ResoNix, you would be paying 7x the overall price and installing 15x more product. In reality, it wouldnt be possible to match the performance of ResoNix CLD Squares with Dynamat Extreme since the performance ceiling is so much lower on Dynamat Extreme. While it’s the name everyone knows, it is not a good performer or a good value.

Dynamat Extreme vs. other popular brands 

Dynamat Extreme shows varying performance levels compared to other popular sound deadeners. It is significantly less effective than ResoNix Mega CLD Squares, which reduced resonance by an additional 19.75dB (11.75dB more than Dynamat), making ResoNix 15 times better in performance. Dynamat Extreme performs about equally with Kilmat 80-mil in terms of resonance reduction, but it has a much better heat resistance. In comparison to Soundskins 3-in-1, Dynamat is slightly outperformed in resonance reduction. However, Soundskins, like Kilmat, is known to have issues with heat resistance and has multiple reports of melting.

STP, short for Standartplast, is a Russian manufacturer that is the company that seems to make some of the other Amazon-sold products that are popular such as Noico, Kilmat, etc. (before said amazon products moved to Chinese manufacturers). Since the start of the Ukranian war, STP products are no longer imported into the US, but we figured the data can be useful. I also have a lot of experience using this product since a shop I worked for years ago used it, and I always had a hunch that STP silver was the very same product as older versions of Kilmat or Noico, especially considering Standartplast makes both. Let’s see what the data says. According to Chris’s testing, STP Silver reduced the test panel resonance peak by 7.75db, close enough to Kilmat to say that they are or were probably the same product. With a reduction of only 7.75db, it puts ResoNix Mega CLD Squares as 16x better due to its 19.75dB test panel resonance reduction. According to the price sheet, it came in at $2.71 per square foot, which gives it a price to performance of  $43.36 compared to ResoNix Mega CLD Squares $14.25. Another thing to note, considering I have a lot of experience with this product from years of installing it while working at another shop, it does not hold up well to heat over time. It tuned into a vaseline-like consistency after a couple years of being in my doors. I used a large spoon to remove the goop that its butyl turned into.

STP Silver vs. other popular brands

STP Silver sound deadener has varying results when compared to other popular sound deadening products. It is significantly outperformed by ResoNix Mega CLD Squares, with ResoNix reducing resonance by an additional 12dB, making it 16 times more effective. However, STP Silver is slightly less effective than Dynamat Extreme, with Dynamat reducing resonance by only 0.25dB more, which makes Dynamat 1.05 times better in performance. Compared to Soundskins, STP Silver is also less effective, with Soundskins reducing resonance by 1.25dB more, making it 1.35 times better. When pitted against Kilmat 80mil, STP Silver performs slightly better, reducing resonance by an additional 0.5dB, making it 1.12 times more effective.

Note: The SoundShield that was tested was their standard product, not the slim version, or vinyl-based product. I would be lying to say I wasn’t anticipating seeing this product tested. SoundShield has become extremely popular in the inner circles of the car audio industry in recent years after the owner parted ways from distributing SoundSkins in the US. 

Frankly, the only thing that appeared to be new were the logos. SoundShield is another one of the “3-in-1” products made overseas by a less than reputable manufacturer that has a history of producing some of the worst performing sound deadeners available today (as you will see), both from a resonance control standpoint, as well as their resistance to melting, which there is a long history of complaints for. But how does it actually perform on paper? Let’s find out. 

In the testing results seen in the photo below, SoundShield reduced the resonance peak by only 7dB, much less than the ResoNix Mega CLD Squares 19.75dB. This puts our Mega CLD Squares at a whopping 19 times more effective than SoundShield’s flagship product, and that doesn’t even begin to discuss the resonance decay performance. Not only that, but SoundShield is the worst value by far out of the entire test. It’s a very expensive product for how cheap it really is, and comes out to a price to performance equivalence of a whopping $259.16 versus the ResoNix Mega CLD Squares $14.25. Sheesh. Considering the resonance control performance, history of melting from the manufacturer, and price to performance ratio… I have no words.

Also, considering they have the same results and same manufacturer, I think its safe to say the only difference between this and Sonic Barrier is the logo. 

SoundShield vs. other popular brands

SoundShield 3-in-1 sound deadener shows some very unfavorable effectiveness when compared to other popular brands. It is significantly less effective than ResoNix Mega CLD Squares, which reduced the test panels’s resonance by 12.75dB more than SoundShield, making ResoNix 19 times more effective. Against Dynamat Extreme, SoundShield is slightly less effective, with Dynamat reducing resonance by an additional 1dB, resulting in Dynamat being 1.25 times better. In comparison with Soundskins, a similar product with a shared business history, SoundShield is outperformed as Soundskins reduced the test panels resonance by 2dB more, making it 1.6 times more effective. I’m sure we can all guess why a business using the same original manufacturer of both would opt for a lower performing product, but that’s probably pretty easy to guess and for you to decide.

Another “3-in-1” product from “that” manufacturer and is another popular option among car audio shops. Due to the history of SoundSkins/Soundshield in the US, I always suspected they were identical products. While I don’t expect much from the aforementioned manufacturer or the brands that order from them, they can still request different thicknesses in butyl, aluminum, and foam, which can change performance. It’s hard to say because these companies don’t even seem to care enough to put thickness specs in their literature. Let’s see if my suspicions were correct.

Turns out, I was wrong. Spoiler alert, it looks like SoundSkins is a slightly better performer than SoundShield. There is most likely a difference in butyl thickness. The word is, Soundskins changed to the other usual manufacturer that produces the popular 3-in-1 products due to the poor history of melting and overall performance by the previous manufacturer. According to public import records, SoundShield still uses the original manufacturer that has the history of melting products.

Next up, we have Sonic Barrier MX-4. Another 3-in-1 product similar to SoundShield, Soundskins, Roadstage, etc. Frankly, there are a LOT of products like this nowadays. Almost all of them are made by one manufacturer overseas with a different logo applied for each brand. Sonic Barrier is one of the ones in the “same as the rest” group. The only difference you can really get is butyl and foam thickness.

So, getting into the test results. Sonic Barrier MX-4 reduced the panel resonance by 5.75dB, the second lowest of anything tested so far. ResoNix Mega CLD Squares being at 19.75dB in reduction of resonance on the test panel puts it at a staggering 25.5x better than Sonic Barrier MX-4. The price, when it was still sold was $2.85 per square foot, giving it a price to performance ratio of $72.68 against ResoNix Mega CLD Squares $14.25.

Sonic Barrier vs. other popular brands 

Sonic Barrier MX4 Sound Deadener heavily underperforms compared to other popular sound deadening products. Against ResoNix Mega CLD Squares, it performs significantly worse, with ResoNix reducing resonance by 14dB more, making it 25.5 times more effective. When compared to Soundskins 3-in-1, Sonic Barrier reduces resonance by 3.25dB less, resulting in Soundskins being 2.1 times better. Against Kilmat 80-mil Sound Deadener, Sonic Barrier also falls short, with Kilmat 80-mil reducing resonance by 1.5dB more, making it 1.4 times as effective. Finally, when compared to Dynamat Extreme, Sonic Barrier is less effective, as Dynamat reduces resonance by 2.25dB more, making it 1.7 times better in performance. 

Note For Buyers & Users Of Sonic Barrier, and other "3-in-1" Sound Deadening Products: Something to take note of regarding the info above, while they don’t have the same thickness specs, the manufacturer of Sonic Barrier also makes pretty much all of the popular “3-in-1” products, such as Soundshield, Sound Skins, SQL Sound Mat, Sky High 3-in-1, GP STFU, Siless Hybrid, Focal, Blackhole, Morel Accudamp, DC Audio, Sundown, B2, and more. These all use the same butyl formula that is known for poor resonance control, failure of performance due to heat cycles, as well as completely melting (as seen in the Reference Information & Guide page). Buyer beware.