Wet Sounds™ Hydro-Tech™ X (HTX) Series Amplifier. Wet Sounds represents the ultimate in High Performance Marine Audio. Wet Sounds HTX Series Marine Amplifiers are designed to be a complete solution for every type of extreme marine application. HTX amplifiers use superior performance circuitry by utilizing Class D Power Supplies. These amplifiers have extreme power output packed inside a small chassis, thermal overload protection, flexible crossovers, extended inputs. HTX amplifiers are a well balanced match for all of the Wet Sounds™ products.