The S10.4 powered studio subwoofer builds upon KRK’s legacy for sonic accuracy and performance. The custom-voiced, glass-aramid woofer delivers tight, defined bass, while the Class-D power amplifier dramatically increases transient response, control and punch. The four-position selectable crossover makes it easy to adjust the subwoofer setting to your existing monitors. Pairing the S10.4 with KRK or another studio monitors delivers an optimized listening and mixing experience with extended low end, while the exclusive bypass-control feature provides full range audio to the monitors without switching off the subwoofer. KRK's S10.4 subwoofer doesn’t just deliver precise bass and a rich feature set: it’s the next dimension in subwoofer performance. S10.4 Features 10" glass aramid composite woofer Bass extension to 28Hz with a max SPL of 117 dB Footswitch control enables/disables sub and crossover filter (footswitch not included) Curved design with front-firing bass port for placement flexibility Powerful, lightweight Class D amplification Optimized four-position crossover control Universal connectivity: XLR, 1/4" TRS, and RCA inputs and outputs Polarity and input sensitivity controls All-steel grill and 15 mm reinforced MDF enclosure provide maximum strength and protection Ground lift switch prevents ground loops