The HD15 Bass Combo by Hartke incorporates a 15W amplifier and a 6.5" Hydrive series hybrid cone bass speaker within a sturdy, portable enclosure. The hybrid cone speaker is constructed using an outside paper cone for warm low frequencies, and an inside aluminum cone for punchy mids. The Combo's top-mounted amplifier panel offers bass, mid, treble, and overall volume controls. A further feature of the HD15 Combo is a dedicated 3.5mm line input for hooking up a portable CD or MP3 player to practice along with. A 1/4" headphone output is also provided for quiet practice sessions; when a plug is inserted into it, the speaker output is disconnected, allowing you to use your HD15 at any time without disturbing others. A built-in limiter ensures constant amplifier operation at safe levels. The enclosure is designed with a perforated metal grill and a molded strap top carry handle. The HD15 Bass Combo is ideal for use in rehearsal spaces, private practice sessions, and small venues, and accommodates all musical styles.