Powered speakers

Active speaker system or powered speakers (English powered speaker ) denotes an integrated unit from the speaker and amplifier in a housing ( box); the contrast is a passive box that does not contain amplifiers.

Begriffsetymologie

In the original sense are referred to as active speaker system speaker systems that are equipped with active crossovers, several external or internal amplifiers and speaker cabinets. A built- in one or more boxes amplifier is not necessary in this original sense.

With the increasing penetration of broadband systems with built-in amplifier, the term was extended to those systems that do not use active crossover, but instead are characterized by an integrated amplifier. In this sense, these boxes amplify the input signal is active.

History

Some of the first active speakers were monitor speakers from JBL. Of 1964, JBL in front of the speaker amplifier SE401 Stereo Energizer. Through its installation any pair monitor speakers could be converted into a pair of active speakers and an operated by the passive cabinet.

An early example of a studio monitor speakers with bi-amplification and active crossover is the Altec 9846B from the year 1971. This combines the passive speaker Altec 9846 -8A with the new 771B Bi -Amp. This provides 60 watts for the woofer and 30 watts for the tweeter ready.

Internal structure

The integrated amplifier requires its own power supply, which is why powered speakers are always operated with AC adapter or batteries ( or rechargeable batteries ). An external amplifier is eliminated.

In Multi-way active speakers the necessary frequency division can take place both before and behind the amplifier. In simpler systems - only one amplifier needed - a passive crossover between the power amplifier and the chassis is usually used. ( The phrase " passive " here refers only to the internal structure of the switch itself, and otherwise has little to do with the active or passive mode of speakers. ) For more complex or professional systems, however, each speaker is powered by its own amplifier; signal processing - frequency filtering, etc. - is then before the relevant final amplification. And various combinations of these systems are possible.

Pros and Cons

The relevance of the advantages and disadvantages will depend in part on the intended use.

  • Easy to use, since one or more additional devices (amplifier ) account
  • Precise adjustment of the amplifier to the speakers used Accurate power rating of the amplifier to the speaker
  • Avoid damage to the amplifier or loudspeaker volume by mismatched or overloaded components
  • Possibly lower costs than the combination of passive speaker and amplifier, as the cost of the passive lying in the power range crossover can be saved
  • Reduced flexibility; Amplifier and speaker unit (s ) can not be replaced individually
  • In case of failure of a part (speakers or amplifier) ​​, the entire unit must be replaced
  • Higher costs for many of the same speakers, as each box has its own amplifier

Area of ​​use

The most common active speakers are used for the following purposes:

Monitor speakers, studio speakers as a high quality single speaker

  • Crossover to the disentanglement of the bass frequency range
  • Level adaptation for connection to the speaker outputs of an amplifier without matching subwoofer output
  • Merging of stereo signals into a mono signal
  • Phasen-/Pegeleinstellung to adapt to the other speaker
Bi-amping and tri-amping Motional Feedback
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