if a bassist was driving his bass amp speaker stacks into clipping to create a fuzz bass tone, if the audio engineer wished to have a "clean" bass sound, this could pose a challenge. As a result of requests by audio engineers to reduce onstage volume, in the 2010s, in many large venues. much of the on-stage sound reaching the musicians now comes from the monitor speakers or in-ear monitors, not from the instrument amplifiers. Stacks of huge speaker cabinets and amplifiers are still used in concerts in some genres of music, especially heavy metal, but they tend to be used more for the visual effect than for sound reproduction. In some small to mid-size venues, such as bars and nightclubs, the PA system may not have the capacity to provide the bass sound for the venue, and the PA system may be used mainly for vocals. Bass players in bands that play at a variety of venues, including these types of small to mid-size venues, may need to be able to provide the bass sound for the venue, and so they will require a large combo amp or bass stack with this capability. Types Different types of equipment are used to amplify the electric bass and other bass instruments, depending on the performance setting, style of music, the sound desired by the bassist, the size of the venue and other factors, such as whether a bassist is an amateur or professional musician. Professional bassists are more likely to have expensive "boutique" amps and cabinets. All types of bass amps and cabinets are designed to be transportable to shows and recording studios, and as such, most have various features to protect the cabinet (e.g., metal or plastic corner protectors) and speakers (a plastic screen or metal grille) during transportation and move the equipment (a single carry handle is standard for practice amps and combo amps and two handles are sometimes provided for two-handed carrying of large cabinets, and wheels are mounted on some large combo amps and cabinets). Amplifier "heads" may be sold mounted in a wooden cabinet with a carrying handle, or they may be sold as rackmount-able components, which can be screw-mounted in a 19" road case for protection. The speaker enclosures for combo amps and speaker cabinets are typically covered in stiff vinyl, carpet, felt or other sturdy fabric, or painted. Practice amps The smallest bass amps