Bi-amping and tri-amping

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Bi-amping - An active crossover with two amplifiers. Active Crossover.svg
Bi-amping - An active crossover with two amplifiers.

Bi-amping and tri-amping is the practice of using two or three audio amplifiers respectively to amplify different audio frequency ranges, with the amplified signals being routed to different speaker drivers, such as woofers, subwoofers and tweeters. With bi-amping and tri-amping, an audio crossover is used to divide a sound signal into different frequency ranges, each of which is then separately amplified and routed to separate speaker drivers. In Powered speakers using bi-amping, multiple speaker drivers are in the same speaker enclosure. In some bi-amp set-ups, the drivers are in separate speaker enclosures, such as with home stereos that contain two speakers and a separate subwoofer.

Contents

Description

Illustration of tri-amping, using three amplifiers to amplify different parts of a sound. Tri-amping.svg
Illustration of tri-amping, using three amplifiers to amplify different parts of a sound.

Bi-amping is the use of two channels of amplification to power each loudspeaker within an audio system. Tri-amping is the practice of connecting three channels of amplification to a loudspeaker unit: one to power the bass driver (woofer), one to power the mid-range and the third to power the treble driver (tweeter). The terms derive from the prefix bi- meaning 'two', tri- meaning 'three', and amp the abbreviation for amplifier.

Crossover

It differs from the conventional arrangement in which each channel of amplification powers a single speaker. Bi-amping typically consists of a crossover network and two or more drivers. With ordinary loudspeakers, a single amplifier can power the woofer, mid-range and tweeter through an audio crossover, which filters the signal into high- medium- and low-frequencies (or high- and low-frequencies in 2-way speakers) a mechanism that protects each driver from signals outside its frequency range. However, the passive crossover itself is inefficient, so splitting the frequencies electronically before these are amplified is a way to avoid this problem. In such a case, an amplifier each powers a frequency range determined by an active crossover to each of the drive units. The technique is primarily used in large-scale audio applications such as sound amplification for concerts, in portable powered speakers and by hi-fi enthusiasts.

Wiring

A speaker system has to be wired to accommodate either configuration, typically with two sets of binding posts, one set for the bass and one set for the mid-highs. A single amplifier can usually power a woofer and a tweeter only through a post-amplifier crossover filter, which protects each driver from signals outside its frequency range.

Bi-amping of speakers requires double the channels of amplification and can be accomplished using two ordinary amplifiers in either a vertical or horizontal arrangement.

Benefits

Most audible differences are subtle. If at all noticeable, many benefits of bi-amping cannot be realized if passive crossover networks of a speaker system are not removed. [1] Benefits include transients are less likely to cause amplifier overload (clipping) and/or speaker damage, and reduced intermodulation distortion, elimination of errors introduced by low frequency passive crossover, reduction of load presented to the power amplifier, better matching of power amplifier and speaker driver and others. [2] In large professional sound systems, Bi-amping is pretty much the norm with the greater benefits easily outweighing the costs. All speakers are two-way transducers and can introduce current back into the driving circuit from ambient sound. The driving amplifier tries to control the effect of this with its damping factor (having a high resistance to such current), but with a passive crossover, this current can still leak across to the other driver units in the circuit. A Bi-amped system is therefore able to better resist ambient sound feeding back into the circuit. With high volumes and larger venues, such ambient feedback can have a significant damaging effect to the overall sound.

See also

Related Research Articles

<span class="mw-page-title-main">Loudspeaker</span> Converts an electrical audio signal into a corresponding sound

A loudspeaker is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A speaker system, also often simply referred to as a speaker or loudspeaker, comprises one or more such speaker drivers, an enclosure, and electrical connections possibly including a crossover network. The speaker driver can be viewed as a linear motor attached to a diaphragm which couples that motor's movement to motion of air, that is, sound. An audio signal, typically from a microphone, recording, or radio broadcast, is amplified electronically to a power level capable of driving that motor in order to reproduce the sound corresponding to the original unamplified electronic signal. This is thus the opposite function to the microphone; indeed the dynamic speaker driver, by far the most common type, is a linear motor in the same basic configuration as the dynamic microphone which uses such a motor in reverse, as a generator.

<span class="mw-page-title-main">Audio crossover</span> Electronic filter circuitry used in loudspeakers

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 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.

<span class="mw-page-title-main">Tweeter</span> Type of loudspeaker

A tweeter or treble speaker is a special type of loudspeaker that is designed to produce high audio frequencies, typically deliver high frequencies up to 100 kHz. The name is derived from the high pitched sounds made by some birds (tweets), especially in contrast to the low woofs made by many dogs, after which low-frequency drivers are named (woofers).

<span class="mw-page-title-main">Mid-range speaker</span>

A mid-range speaker is a loudspeaker driver that reproduces sound in the frequency range from 250 to 2000 Hz.

A woofer or bass speaker is a technical term for a loudspeaker driver designed to produce low frequency sounds, typically from 20 Hz up to 80 Hz. The name is from the onomatopoeic English word for a dog's deep bark, "woof". The most common design for a woofer is the electrodynamic driver, which typically uses a stiff paper cone, driven by a voice coil surrounded by a magnetic field.

<span class="mw-page-title-main">Guitar amplifier</span> Electronic amplifier for musical instruments

A guitar amplifier is an electronic device or system that strengthens the electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which are typically housed in a wooden cabinet. A guitar amplifier may be a standalone wood or metal cabinet that contains only the power amplifier circuits, requiring the use of a separate speaker cabinet–or it may be a "combo" amplifier, which contains both the amplifier and one or more speakers in a wooden cabinet. There is a wide range of sizes and power ratings for guitar amplifiers, from small, lightweight "practice amplifiers" with a single 6-inch speaker and a 10-watt amp to heavy combo amps with four 10-inch or four 12-inch speakers and a 100-watt amplifier, which are loud enough to use in a nightclub or bar performance.

<span class="mw-page-title-main">Sound reinforcement system</span> Amplified sound system for public events

A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds to a larger or more distant audience. In many situations, a sound reinforcement system is also used to enhance or alter the sound of the sources on the stage, typically by using electronic effects, such as reverb, as opposed to simply amplifying the sources unaltered.

Klipsch Audio Technologies is an American loudspeaker company based in Indianapolis, Indiana. Founded in Hope, Arkansas, in 1946 as 'Klipsch and Associates' by Paul W. Klipsch, the company produces loudspeaker drivers and enclosures, as well as complete loudspeakers for high-end, high-fidelity sound systems, public address applications, and personal computers.

Celestion is a British designer and exporter of professional loudspeakers.

<span class="mw-page-title-main">Powered speakers</span> Loudspeaker that have built-in amplifiers

Powered speakers, also known as self-powered speakers and active speakers, are loudspeakers that have built-in amplifiers. Powered speakers are used in a range of settings, including in sound reinforcement systems, both for the main speakers facing the audience and the monitor speakers facing the performers; by DJs performing at dance events and raves; in private homes as part of hi-fi or home cinema audio systems and as computer speakers. They can be connected directly to a mixing console or other low-level audio signal source without the need for an external amplifier. Some active speakers designed for sound reinforcement system use have an onboard mixing console and microphone preamplifier, which enables microphones to be connected directly to the speaker.

<span class="mw-page-title-main">Loudspeaker enclosure</span> Acoustical component

A loudspeaker enclosure or loudspeaker cabinet is an enclosure in which speaker drivers and associated electronic hardware, such as crossover circuits and, in some cases, power amplifiers, are mounted. Enclosures may range in design from simple, homemade DIY rectangular particleboard boxes to very complex, expensive computer-designed hi-fi cabinets that incorporate composite materials, internal baffles, horns, bass reflex ports and acoustic insulation. Loudspeaker enclosures range in size from small "bookshelf" speaker cabinets with 4-inch (10 cm) woofers and small tweeters designed for listening to music with a hi-fi system in a private home to huge, heavy subwoofer enclosures with multiple 18-inch (46 cm) or even 21-inch (53 cm) speakers in huge enclosures which are designed for use in stadium concert sound reinforcement systems for rock music concerts.

<span class="mw-page-title-main">Bass amplifier</span> Electronic amplifier for musical instruments

A bass amplifier is a musical instrument electronic device that uses electrical power to make lower-pitched instruments such as the bass guitar or double bass loud enough to be heard by the performers and audience. Bass amps typically consist of a preamplifier, tone controls, a power amplifier and one or more loudspeakers ("drivers") in a cabinet.

<span class="mw-page-title-main">Studio monitor</span> Speaker designed to reproduce sound accurately

Studio monitors are loudspeakers in speaker enclosures specifically designed for professional audio production applications, such as recording studios, filmmaking, television studios, radio studios and project or home studios, where accurate audio reproduction is crucial. Among audio engineers, the term monitor implies that the speaker is designed to produce relatively flat (linear) phase and frequency responses. In other words, it exhibits minimal emphasis or de-emphasis of particular frequencies, the loudspeaker gives an accurate reproduction of the tonal qualities of the source audio, and there will be no relative phase shift of particular frequencies—meaning no distortion in sound-stage perspective for stereo recordings. Beyond stereo sound-stage requirements, a linear phase response helps impulse response remain true to source without encountering "smearing". An unqualified reference to a monitor often refers to a near-field design. This is a speaker small enough to sit on a stand or desk in proximity to the listener, so that most of the sound that the listener hears is coming directly from the speaker, rather than reflecting off walls and ceilings. Monitor speakers may include more than one type of driver or, for monitoring low-frequency sounds, such as bass drum, additional subwoofer cabinets may be used.

<span class="mw-page-title-main">Guitar speaker</span>

A guitar speaker is a loudspeaker – specifically the driver (transducer) part – designed for use in a combination guitar amplifier of an electric guitar, or for use in a guitar speaker cabinet. Typically these drivers produce only the frequency range relevant to electric guitars, which is similar to a regular woofer type driver, which is approximately 75 Hz — 5 kHz, or for electric bass speakers, down to 41 Hz  for regular four-string basses or down to about 30 Hz for five-string instruments.

<span class="mw-page-title-main">Bi-wiring</span> Method of running wires to speakers

Bi-wiring is a means of connecting a loudspeaker to an audio amplifier, primarily used in hi-fi systems. Normally, there is one pair of connectors on a loudspeaker and a single cable runs from the amplifier output to the terminals at the loudspeaker housing. From this point, connections are made to the loudspeaker drivers – usually through audio crossover networks.

<span class="mw-page-title-main">Electrodynamic speaker driver</span> Individual transducer that converts an electrical audio signal to sound waves

An electrodynamic speaker driver, often called simply a speaker driver when the type is implicit, is an individual transducer that converts an electrical audio signal to sound waves. While the term is sometimes used interchangeably with the term speaker (loudspeaker), it is usually applied to specialized transducers which reproduce only a portion of the audible frequency range. For high fidelity reproduction of sound, multiple loudspeakers are often mounted in the same enclosure, each reproducing a different part of the audible frequency range. In this case the individual speakers are referred to as drivers and the entire unit is called a loudspeaker. Drivers made for reproducing high audio frequencies are called tweeters, those for middle frequencies are called mid-range drivers, and those for low frequencies are called woofers, while those for very low bass range are subwoofers. Less common types of drivers are supertweeters and rotary woofers.

<span class="mw-page-title-main">Stage monitor system</span> Sound reinforcement for performers

A stage monitor system is a set of performer-facing loudspeakers called monitor speakers, stage monitors, floor monitors, wedges, or foldbacks on stage during live music performances in which a sound reinforcement system is used to amplify a performance for the audience. The monitor system allows musicians to hear themselves and fellow band members clearly.

<span class="mw-page-title-main">Equalization (audio)</span> Changing the balance of frequency components in an audio signal

Equalization, or simply EQ, in sound recording and reproduction is the process of adjusting the volume of different frequency bands within an audio signal. The circuit or equipment used to achieve this is called an equalizer.

<span class="mw-page-title-main">Keyboard amplifier</span>

A keyboard amplifier is a powered electronic amplifier and loudspeaker in a wooden 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.

<span class="mw-page-title-main">Linn Isobarik</span> Loudspeaker designed and manufactured by Linn Products

The Linn Isobarik, nicknamed "Bariks" or "Briks", is a loudspeaker designed and manufactured by Linn Products. The Isobarik is known for both its reproduction of low bass frequencies and being very demanding on amplifiers.

References

  1. An article from Audioholics online A/V magazine, 30 August 2004 , The Difference Between Biamping vs. Biwiring
  2. Elliott, Rod (7 July 2017) [Originally published 1998]. "Benefits of Bi-Amping (Not Quite Magic, But Close) - Parts 1 & 2". Not Quite Magic, But Close). Elliott Sound Products. Archived from the original on 17 July 2019.