The HyDrive Design The HD150 boasts Hartke's patented HyDrive speaker technology, offering a expertly designed hybrid (half paper, half aluminum) bass speaker. Combining the warmth and mellow characters of paper with the punch and attack of aluminum, the HyDrive design delivers serious tone perfect for bassists of any genre or style. Solid... With Style With a bevy of professional features, the HD150 combo was designed with ease of use and reliability for players of all skill levels in mind. The combo features Volume, Bass, Middle and Treble controls on a top-mounted panel, along with a powerful 7-band graphic EQ for simpler adjustments. Includes a full effects loop, a 1/8 aux input for jamming along with your favorite songs on a MP3 player, and a 1/4 headphone output for silent practice sessions. The HD150 also has an XLR direct output for sending the signal to a mixers in both live and studio environments. Additionally, the HD150 features an integrated limiter to keep the amp response consistent and safe at any levels. A robust and elegant enclosure rounds out the experience with a stylishly finished perforated metal grille, side carrying handles, and castors. Hartke's HD150 Bass Combo goes far beyond typical bass combo amps on the market, with the incredible and unique character of HyDrive speakers housed in a durable and very portable cabinet. Features and Specs 150 watts of output power 15 HyDrive paper and aluminum cone driver 1 tweeter Top-mounted amplifier with Volume, Bass, Mid and Treble controls 7-band graphic EQ 1/4 input for active and passive bass guitars 1/8 stereo Aux input for stereo line level devices (MP3 players, drum machines, etc.) 1/4 headphone output XLR direct output Built-in limiter Effects loop Perforated metal grille Side carry handles Casters included