the live drummer can play along with them. Sound system Some electronic drum manufacturers sell electronic drum-specific combination amplifiers, which contain a power amplifier and one or more speakers in a wooden, wedge-shaped cabinet. The wedge shape is designed so that the speaker is directed at a seated drummer, much like a vocalist's monitor speaker will often be wedge-shaped. Some electronic drummers use keyboard amplifiers or PA systems (both of which are full-range systems). For individual practice, headphones can be connected to the drum module's headphone jack. Other gear A bass drum pedal may be needed in some kits. As well, some electronic cymbals can be mounted on regular cymbal stands. Drummers also use accessories, such as a drum throne, which is a small padded stool. Variations Table-top electronic drum A table-top electronic drum (or portable electronic drum) is an electronic drum that has all of its pads (except foot pedals) and the electronic sound module combined in a single table-top unit. It may have a small amplifier and small loudspeakers incorporated so that it can be used at jam sessions without plugging into a PA system. The sound generation is generally simpler (single-layered samples) when compared to more expensive, full-size electronic kits. Also, the feel when playing a table-top drum/pad is very different from using a full-size electronic kit or an acoustic kit. The advantages of table-top drums are their portability and the relatively lower price. Some acoustic drummers use a table-top electronic drum as their first foray into electronic drumming, since purchasing a single table-top unit and setting it up alongside an acoustic drum kit is much cheaper and simpler than fitting an entire acoustic kit with sensors and connecting them to a "drum brain" module. With a table-top drum mounted on a stand, a drummer who has an otherwise acoustic drum kit could add different drum and percussion sounds to her playing, such as synthesized drum sounds, or samples of a percussion instrument that would otherwise be impractical to have onstage (e.g., a large gong). Acoustic triggered drum kit An acoustic triggered drum kit is a regular acoustic drum kit coupled with drum trigger/s (sensors) on the drums and cymbals. The triggers can be "built inside" or permanently fixed on to cymbals–so that they are necessarily either: fixed triggers (electronic kit essentially), removable (can be either acoustic or electronic by default of purpose at the time), or