Crutchfield offers the Kicker 400-watt Mono Subwoofer Amplifier, model no. 40KX400.1, bundled with a pair of Kicker Phenom Talk In-Ear Headphones, model no. EB92MB, for $249.99 with free shipping. (Add the amplifier to your cart and the headphones will be automatically included.) That's the lowest price we could find for these items sold separately elsewhere by $30. The subwoofer features variable low-pass filter, Kick EQ, parametric bass boost, front-mounted controls, variable subsonic filter, wired remote level control, and 4-gauge power and ground leads. The headphones feature a frequency response of 10Hz to 50,000kHz, 8mm dynamic drivers, and two ohms impedance.