Blackhole Tiles or ResoNix Guardian - Which Sound Absorber To Use Inside Of Your Car Door

Blackhole Tiles or ResoNix Guardian

Which door cavity rear-wave sound absorber is right for you?

     Blackhole Tiles or ResoNix Guardian. Which sound absorber is best for your car doors, and why? Well, first we need to discuss what they are, and why it is important to have a sound absorber inside your door cavity, especially in car audio installations that feature a door-mounted midbass driver.

       You can read about sound absorbers and noise barriers and composites that are comprised of the two, and how they work in our Reference Information & Guide article. A quick summary, sound absorbers made out of fibrous materials absorb sound by deforming randomly at a microscopic level as sound passes through, converting sound energy into mechanical and thermal energy. The porous materials absorb sound by creating friction against sound waves as they pass through. Noise Barriers are a limp, inert mass that reflects sound away, preventing it from entering the targeted space. Both Blackhole Tiles as well as ResoNix Guardian feature foam-based acoustic absorbers, as well as a floating layer of MLV noise barrier. They both feature a peel-and-stick adhesive backing for easy installation. They both come in at a similar price point per square foot. So which one should you use? 

The Differences Between ResoNix Guardian & Blackhole Tile

       The main difference between the Blackhole Tiles and ResoNix Guardian is the sound absorbing foam layers. Blackhole Tiles feature a standard polyurethane open-cell foam with embossed facing. The bottom layer is 1/4" thick, while the top layer is 1" thick. It also features a sealing agent around its sides to help prevent water intrusion into the foam. While it does feature this sealant, we had to make the decision to stop selling it after many customers mentioned that they were absorbing and holding water. 

       ResoNix Guardian is mostly the same, in that it is the same thickness, features 1lb/square foot Mass Loaded Vinyl, and peel and stick adhesive for easy installation, but takes things in a different direction with the composition of the foam. Instead of the standard polyurethane open-cell foam, it uses a Hydrophobic Acoustic Melamine Foam. Melamine foam offers many benefits over more common polyurethane foams, but for our purposes, we are mostly concerned with the better acoustic absorption performance, as well as the fact that it is able to be manufactured in a way that is completely hydrophobic throughout its entire volume. This ensures that no matter where you install or, or what shapes and sizes you cut it to, water will never be able to absorb inside of the material. This means it'll remain free of mold and mildew, and the products sound absorption performance won't be affected by water clogging the open pores of the foam. 

       The adhesive is also notably different. While we cannot speak for the Blackhole tiles, but we have also had customers report them falling off. We decided to go with an extremely strong acrylic-based adhesive that can withstand the rigors of the automotive environment: heat, cold, moisture, chemicals, you name it, ResoNix Guardian's adhesive will never let go.

       ResoNix Guardian also features polyester acoustic facing. This is the black fabric on the face of the product. While some may think this layer is for looks, it actually serves multiple purposes. This specific material provides a very specific acoustic impedance to further help sound absorption of low frequencies, particularly in the midbass region. Many versions of the same material are available, but since we are mostly using this product for midbass absorption inside of door cavities, we opted to go with the version that targets the best performance under 120hz. This facing is also meant to help stabilize and protect the top layer of the Hydrophobic Melamine foam. If you have ever worked with Acoustic Melamine, you know it is a bit brittle and can be fragile. This layer helps ensure your ResoNix Guardian will not end up damaged.     

       We opted to offer ResoNix Guardian in a 12" x 12" size piece so customers can easily cut them into their desired size and shape to fit anyone installation needs. Both sound absorbers for your car doors work well, but ResoNix Guardian is a clear winner in performance, longevity, reliability, and value. If you have any further questions about ResoNix Guardian or any of our other offerings, please feel free to reach out anytime. Thank you!