Check the listing for details. JBL LSR310S 10-inch Powered Studio Subwoofer. Condition: Very Good - Refurbished. Listed at 398.65 USD. Designed as a companion to JBL's LSR active studio monitor series, the LSR310S powered subwoofer takes the low-end load off of your nearfields. A 10" down-firing driver delivers tight and focused bass, so you get truly balanced 3-way sound. Onboard the LSR310S, you'll find a selectable crossover that sports JBL's XLF Extended Low Frequency Setting, giving you plenty of flexibility to get the low-end contour you need. Ask anyone at Sweetwater: adding a subwoofer to your studio, such as the JBL LSR310S, makes is easier to create great-sounding productions. JBL's Slip Stream port ensures that the LSR310S provides tight and focused bass at any volume. A wide selection of inputs and outputs let you integrate this sub into your studio quickly. Hear what you've been missing in your studio with the JBL LSR310S active studio monitor.