Bass amplifier in the context of Sound pressure level

The bass guitar, also known as the electric bass guitar, is the lowest-pitched member of the guitar family. It is similar in appearance and construction to an electric guitar but with a longer neck and scale length. The electric bass guitar most commonly has four strings, though five-, six-, and seven-stringed models are also built. Since the mid-1950s, the electric bass guitar has often replaced the double bass in popular music due to its lighter weight, smaller size and easier portability, most models' inclusion of frets for easier intonation, and electromagnetic pickups for amplification.

The electric bass guitar is usually tuned the same as the double bass, corresponding to pitches one octave lower than the four lowest-pitched strings of a guitar (typically E, A, D, and G). It is played with the fingers and thumb or with a pick.

Audio crossovers are a type of electronic filter circuitry that splits an audio signal into two or more frequency ranges, so that the signals can be sent to loudspeaker drivers that are designed to operate within different frequency ranges. The crossover filters can be either active or passive. They are often described as two-way or three-way, which indicate, respectively, that the crossover splits a given signal into two frequency ranges or three frequency ranges. Crossovers are used in loudspeaker cabinets, power amplifiers in consumer electronics (hi-fi, home cinema sound and car audio) and pro audio and musical instrument amplifier products. For the latter two markets, crossovers are used in bass amplifiers, keyboard amplifiers, bass and keyboard speaker enclosures and sound reinforcement system equipment (PA speakers, monitor speakers, subwoofer systems, etc.).

Crossovers are used because most individual loudspeaker drivers are incapable of covering the entire audio spectrum from low frequencies to high frequencies with acceptable relative volume and absence of distortion. Most hi-fi speaker systems and sound reinforcement system speaker cabinets use a combination of multiple loudspeaker drivers, each catering to a different frequency band. A standard simple example is in hi-fi and PA system cabinets that contain a woofer for low and mid frequencies and a tweeter for high frequencies. Since a sound signal source, be it recorded music from a CD player or a live band's mix from an audio console, has all of the low, mid and high frequencies combined, a crossover circuit is used to split the audio signal into separate frequency bands that can be separately routed to loudspeakers, tweeters or horns optimized for those frequency bands.

Bass pedals are an electronic musical instrument with a foot-operated pedal keyboard with a range of one or more octaves. The earliest bass pedals from the 1970s consisted of a pedalboard and analog synthesizer tone generation circuitry packaged together as a unit. The bass pedals are plugged into a bass amplifier or PA system so that their sound can be heard. Since the 1990s, bass pedals are usually MIDI controllers, which have to be connected to a MIDI-compatible computer, electronic synthesizer keyboard, or synth module to produce musical tones. Some 2010s-era bass pedals have both an onboard synth module and a MIDI output.

Bass pedals serve the same function as the pedalboard on a pipe organ or an electric organ, and usually produce sounds in the bass range, which, in organ terminology is the 16′ stop. Some bass pedals have an 8′ stop (an octave higher) which can be used by itself or combined with the 16' stop. Bass pedals are used by keyboard players as an adjunct to their full-range manual keyboards (the keyboards played with the hands), by performers of other instruments (e.g., electric bass or electric guitar), or by themselves. Bass pedal units usually have a smaller range (13 notes) than a church pipe organ's pedal keyboard (32 notes for an American Guild of Organists standard pedalboard). Bass pedals with larger ranges are less common, but do exist, such as 17 notes (C to E), 20 notes (C to G), and 25 notes (C to C two octaves higher). As well, bass pedals usually have shorter pedals than those on a church pipe organ's pedalboard.

A keyboard amplifier is a powered electronic amplifier and loudspeaker in a speaker cabinet used for the amplification of electronic keyboard instruments. Keyboard amplifiers are distinct from other types of amplification systems such as guitar amplifiers due to the particular challenges associated with making keyboards sound louder on stage; namely, to provide solid low-frequency sound reproduction for the deep basslines that keyboards can play and crisp high-frequency sound for the high-register notes. Another difference between keyboard amplifiers and guitar/bass amplifiers is that keyboard amps are usually designed with a relatively flat frequency response and low distortion. In contrast, many guitar and bass amp designers purposely make their amplifiers modify the frequency response, typically to "roll-off" very high frequencies, and most rock and blues guitar amps, and since the 1980s and 1990s, even many bass amps are designed to add distortion or overdrive to the instrument tone (for bass, this is called "fuzz bass").

Keyboard amplifiers differ from guitar amplifiers and bass amplifiers in that whereas guitar and bass amps are usually designed for use with one guitar at a time, keyboard amplifiers almost always have a mixer with inputs for two, three, or four keyboards, because many performers often use multiple keyboards. For example, a single player may perform with a stage piano, a keytar and a synthesizer keyboard. Each channel input typically has its own pre-amplifier and volume knob. Keyboard amps in the lower cost range and power output range may only provide equalization controls (for modifying the bass and treble response) for the overall mix. Higher-priced, higher power output keyboard amps designed for professionals may have equalizer controls for each channel. Keyboard amplifiers also differ from guitar amps and bass amps in that whereas many guitar and bass amplifier companies often sell standalone amplifier units (which contain a preamplifier and power amplifier) for use with one or more separate speaker enclosures, keyboard amplifiers are almost always combination (or "combo") amplifiers, so-named because they combine a preamplifier, power amplifier, full-range speaker, and a horn-loaded tweeter, all in a single wooden speaker cabinet.

A professional audio store is a retail business that sells, and in many cases rents, sound reinforcement system equipment and PA system components used in music concerts, live shows, dance parties and speaking events. This equipment typically includes microphones, power amplifiers, electronic effects units (e.g., reverb and compression effects), speaker enclosures, monitor speakers, subwoofers and audio consoles (mixers). Some professional audio stores also sell sound recording equipment, DJ equipment, lighting equipment used in nightclubs and concerts and video equipment used in events, such as video projectors and screens. Some professional audio stores rent "backline" equipment used in rock and pop shows, such as stage pianos and bass amplifiers. While professional audio stores typically focus on selling new merchandise, some stores also sell used equipment, which is often the equipment that the company has previously rented out for shows and events.