Studio sub from day one. Moved to a live room mixing format and a lot of mobile recording and I’ve learn to work without the Sab one less thing to bring. Sounds great I bought a new from guitar center.

From the website

The 10s 10" 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 powered Amplifier dramatically increases transient response, control and punch, allowing you to properly engineer the low-frequency portion of the mix. The 4-position selectable crossover makes it easy to adjust the subwoofer setting to your existing monitors. Pairing the 10s 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 if needed, without switching off the subwoofer. KRK’s 10s subwoofer doesn’t just deliver precise bass and a rich feature set: it’s the next dimension in subwoofer performance.

10" glass aramid composite woofer Bass extension to 28Hz with a max SPL of 117dB Footswitch input 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 grille and 15 mm reinforced MDF enclosure provide maximum strength and protection Ground lift switch prevents ground loops