a stronger and more solid tone. Some players use the more nimble tips of the fingers to play fast-moving solo passages or to pluck lightly for quiet tunes. Using amplification gives the player more control over the tone of the instrument, because amplifiers have equalization controls that can accentuate certain frequencies (often the bass frequencies) while de-accentuating some frequencies (often the high frequencies, so that there is less finger noise). While jazz double bass players use amplification, they typically use much smaller, lower-powered bass amplifiers and smaller speaker cabinets than those used by an electric bass player playing in a jazz fusion show. An upright player performing at a small club may only bring a 1x12" combo amp to the gig. When a small jazz combo is playing in a small jazz club, the double bass player may use only a modest amount of amplification, so that the audience is hearing a mixture of the natural acoustic tone and the amplified sound; if that same band were to play on a huge jazz festival mainstage, all of the bass tone reaching the audience's ears will be from the sound reinforcement system. An unamplified acoustic bass' tone is limited by the frequency responsiveness of the instrument's hollow body, which means that the very low pitches may not be as loud as the higher pitches. With an amplifier and equalization devices, a bass player can boost the low frequencies, which evens out the frequency response. As well, the use of an amplifier can increase the sustain of the instrument, which is particularly useful for accompaniment during ballads and for melodic solos with long held notes. Like other acoustic instruments used with amplification, such as the jazz violin, a double bass is often plugged into a preamplifier, impedance-matching device, and/or a Direct Injection (DI box) box before it is routed to the PA system, electronic effects, or the bass instrument amplifier. In traditional jazz and swing it is sometimes played in the slap style. This is a vigorous version of pizzicato where the strings are "slapped" against the fingerboard between the main notes of the bass line, producing a snare drum-like percussive sound. The main notes are either played normally or by pulling the string away from the fingerboard and releasing it so that it bounces off the fingerboard, producing a distinctive percussive attack in addition to the expected pitch. Notable slap style