Roland's newest and most advanced bass amplifiers employ proprietary FFP and Active Speaker Control technology for fast response and high-quality bass tone. Two combo models (115 and 210) offer different wattages and speaker configurations to accommodate a variety of needs and tastes. A powered extension speaker (model 115X) adds another layer of punch for performers who play larger venues. To achieve their sound, the new D-Bass amps employ two Roland technologies: FFP and Active Speaker Control. Active Speaker Control allows the D-Bass to reproduce the incoming signal of the original bass, controlling its speaker movement to match the input signal, according to Roland. This "true input matching" technology allows sounds to be much tighter, much clearer, punchier, and the overall feel to be more direct than with other bass amplifiers.