Sound Storm Laboratories Marine speakers feature poly-injection cones, mylar dome tweeters, and aluminum voice coils. The H2O9 is Sound Storm’s flagship marine speaker boasting 400 watts of peak power handling. This 4 ohm marine speaker possesses a 50 ounce magnet structure and one inch voice coil. This is an efficient speaker (at 92dB W/M) that has a frequency response range from 60Hz to 20kHz. The custom plastic grilles aggressively protect the cone from injury while simultaneously providing smooth channels for the drainage of water. Wet or dry, SSL Marine speakers are creating quite a splash in the industry. For technical questions about this product please visit our website, www.soundstormlab.com, or call a technician at 888.38.STORM. Let us prove to you that when it comes to building an impressive and affordable home-quality theater in your vehicle, Sound Storm is your mobile entertainment solution…and everything else is just noise.