It is a scientific fact that water vapor in the air scatters or refracts Radio Frequency (RF) energy. With the proliferation of audio streaming services and devices, this scattering effect, previously only an issue to the scientific and military communities, is now a common source of disappointing audio playback, particularly in areas that have humidity.

Let’s take a look at the following equation: 


  • n = index of refraction 
  • T = temperature (°K)
  • P = localized atmospheric pressure (mbar)
  • e = water vapor pressure (mbar)


One can clearly see from this equation that humidity (e) wreaks havoc on Wi-Fi and Bluetooth audio streaming. Of course, not everyone will hear the differences but to those of you who can, humidity cannot be understated.

There are three types of scattering that can affect wireless streaming audio:

  • Lambertian (aka isotropic reflectance) which occurs when rays are equally reflected in all directions, (e.g., fog).
  • Specular reflectance occurs when rays are scattered in a specific direction, such as over a smooth body of water.
  • Diffuse reflectance occurs when RF energy is diffused.


To prove this further, let’s look at another equation:


  • T is temperature (°K)
  • p is atmospheric pressure (mbar)
  • e is partial water vapor pressure (mbar)
  • z is height above surface (meters)


With the introduction of the modified refractivity parameter, M, in the above equation, one can clearly see that this is a problem.KEF Hydro Blaster

As the audio world forges on into unknown territory, relying more and more on science to deliver us clean, enjoyable wireless audio, problems like the ones illustrated above are only going to increase. That’s why we here at KEF are so excited to announce Hydro Blaster, a new product that is going to revolutionize Wi-Fi and Bluetooth wireless audio streaming.

This outstanding solution effectively removes unwanted water vapor from the air. As we now know, environmental conditions such as high ambient humidity can have negative effects on the quality of RF signal transmissions (as proven by the equations above and by anyone who has tried to use their cell phone in a rain storm). By removing unwanted water vapor the wireless audio signal transmission in the listening area is vastly improved.

Exhaustive blind listening tests have proven conclusively that the quality of sound received once the room has been sprayed with KEF Hydro Blaster is sharper, clearer and more dynamic. Prior to this amazing development, results like this were only possible in highly controlled humidity-proof wireless listening rooms that were affordable to only a few audiophiles world-wide. Now with KEF’s Hydro Blaster, enhanced humidity-free wireless listening is available to anyone with just a few quick sprays.

As if all of this weren’t enough: several wireless carriers are looking at Hydro Blaster technology for large-scale use in humidity-prone geographic areas with inherently poor cell phone reception.

Please check out our video demonstration of Hydro Blaster. We think you’ll be well convinced of its efficacy.