stereo system

from Wikipedia, the free encyclopedia
Stereo system from Sony from the 1990s with the individual components integrated amplifier , CD player and cassette deck (from below)

The term stereo (from the procedure Stereofonie , rarely, hi-fi system , from the English. High Fidelity for "high fidelity") refers to a collection of devices of consumer electronics for sound reproduction of media such as compact discs and other, mostly digital media . Until the prevalence of CD in the 1980s were only as source media analog media such as the vinyl record , cassette and tape used. The term is justified if two simultaneous but separate sound signals ( channels ) are processed and reproduced for the purpose of binaural spatial listening, which is also known as stereophony.

Colloquially, the term is now used more generally for devices for higher-quality, multi-channel sound reproduction in the private sector . In the case of systems for public stereo reproduction or sound reproduction in general (at concerts , in discotheques, etc.), on the other hand, one speaks of sound systems . Classic stereo systems in households are increasingly being replaced by so-called home theater systems, which were originally developed for playing back the multi-channel sound formats supplied by DVD and Blu-ray Disc .

A stereo system today typically consists of at least one player or source device, e.g. B. a CD / DVD or MP3 player , an amplifier component and at least two spatially separated speaker boxes .


Stereo combination RR 126 (Italy, 1966)
Vision 2000 (Germany, 1971) Design Thilo Oerke

Forerunners of the stereo systems were the music chests of the 1950s (among others von Braun ), which meant combinations of turntables , radio and possibly also home tape recorder and television in a common housing. As a rule, however, they only had monophonic , i.e. single-channel, sound. Stereophonic , i.e. two-channel records , have been sold since 1958; the radio radiates in West Germany since 1963 stereophonic broadcasts. Since the same time stereo-compatible record players, radio receivers and tape recorders have also been available. From the first half of the 1960s onwards one can speak of stereo systems in the modern sense (single or combination devices with speakers that can be set up separately). In the late 1960s and 1970s, compact systems in the form of top loaders were very common. They were operated from above, were flat and wide, mostly had a cover made of acrylic glass and often a stand. Usually they included turntables, radio receivers and amplifiers , and often a cassette deck . From the 1980s onwards, they were replaced by hi-fi towers made from individual components. In the 1970s, so-called quad- phonic systems with four channels or loudspeakers came onto the market, but these did not catch on.

Top loader by Braun , 1964/65, exhibited in the Pinakothek der Moderne in Munich

Up until the 1980s, stereo systems were so large for technical reasons that they were also their own (sometimes decorative) pieces of furniture . They were also comparatively expensive, so that their own stereo system was one of the first major purchases in the lives of many teenagers and represented a status symbol . At that time, a typical investment of a consisted record player , a FM - broadcast receiver , a booster , a cassette deck (rare: tape recorder ) and a pair of speakers . CD players came onto the market in the early 1980s and became increasingly popular around the middle of the decade. Ever since video recorders and television sets became stereo-compatible, they were increasingly interconnected with hi-fi systems, which later became even more pronounced with the increasing spread of digital home theater systems from around the 2000s.

Since the 1990s, other (mostly digital) sound carrier and reception formats came on the market in quick succession, the playback devices of which were integrated into existing stereo systems. Most formats, however, could not establish themselves on the market (such as digital satellite radio and the digital compact cassette ) or quickly disappeared again after moderate success, such as MiniDisc and DAT . In many cases, the personal computer (PC) has also been integrated into existing systems thanks to its audio capabilities that are now suitable for HiFi . This development was mainly driven by the triumphant advance of the MP3 format from the beginning of the 2000s.

Since the spread of home cinema systems with more than two channels (mostly 5.1 surround sound systems) have played an increasing role. Therefore, the term stereo system, although it is also used in everyday language for multi-channel systems, is often actually no longer applicable.


The loudspeaker boxes are a necessary component .

A stereo system comprises the entire signal chain for sound reproduction, consisting of at least one source component, one amplifier component and one loudspeaker component:

Source components are responsible for reading out the (analog or digital ) audio signal.

Amplifier components amplify the analog signal from the source device and can change it if necessary. In addition to integrated amplifiers, there are also preamplifiers and power amplifiers as separate devices. There is also a receiver , a combination of amplifier and tuner (receiver). There is also the option of using an equalizer to adapt the sound to personal preferences or the acoustics of the listening room.

The loudspeaker components are responsible for converting the electrical signal into sound. Depending on the number of channels, several loudspeaker boxes are required.

  • Most hi-fi loudspeakers are currently passive , so they do not have their own power output stages and must be operated on external amplifier components ("output stages").
  • Active loudspeakers have an active loudspeaker crossover which divides the audio signal at line level into the frequency ranges required for the individual loudspeaker chassis. The necessary power amplifier components and sometimes even digital-to-analog converters are already integrated in active loudspeakers. Loudspeakers equipped with amplifiers, in which the different frequency ranges are divided up in the power range behind the output stage outputs, are often incorrectly referred to as active loudspeakers.
  • Due to their fundamental technical and constructive superiority, studio loudspeakers prevail in the field of recording studio technology from around 1967.
  • Subwoofers are loudspeakers that are specially designed to reproduce low frequencies.
  • Headphones can also be used instead of the loudspeakers .

In addition to these main components, the components, connecting cables, connection terminals, power supply units, active sound filters, housings and installation elements also have an influence on the quality of the playback.


Hi-Fi tower
In the classic hi-fi tower, all stand-alone devices are stacked on top of each other. This often happens in a separate piece of furniture ( hi-fi rack ). The turntable then automatically occupies the top level. Devices from different manufacturers can be combined. The loudspeakers are placed a few meters apart.
Compact system
In a compact system, all devices are combined in one housing with a uniform user interface. Without a turntable, they usually have space on a shelf. A distinction is made between front loaders , which visually resemble a hi-fi tower, and flatter and wider top loaders that are operated from above. These were particularly common in the 1970s. Here, too, the loudspeakers are set up separately; In the case of later compact systems, a flush installation with a permanent mechanical connection to the system was also common. The development of smaller but almost equally powerful speakers also contributed to this.
Car hi-fi
System built into the car, the components of which are housed in different parts of the car. The loudspeakers are often integrated in the front doors, in the A-pillars and the bass loudspeaker mostly in the trunk.
Digital minimal system
Hi-Fi configuration that has become more and more common recently, in which a computer or network player is used as the source and either only active speakers or an amplifier with a D / A converter are connected.

Home theater system

An AV receiver with a DVD player . In many households, such home cinema systems connected to the television with surround sound via up to eight or more loudspeakers are also used to listen to music, so they have replaced the classic two-channel stereo system.

Due to the widespread use of DVD players that deliver surround sound in the Dolby Digital 5.1 DVD sound format , the classic stereo system and so-called home theater systems grew together in the 2000s . The amplifiers for the 5.1 sound - so-called AV receivers - and the loudspeaker system were increasingly used for listening to CDs or MP3 files stored on a PC or hard drive . Later, the receivers were also connected to the Internet via LAN or WLAN and also served as playback devices for music streaming services such as Spotify . About the introduction of the Blu-ray disc for Full HD -Video in 2005 were also more complex for their new audio formats 7.1 - multichannel sound systems with seven speakers plus a bass loudspeaker ( subwoofer ) on the market.

Since the systems described above are just as suitable or better than conventional stereo systems for normal listening to music and, in addition, for example, coupling with online music services from providers such as Apple Music or Amazon Music is usually easily possible or prepared in the device, such systems are increasingly replacing classic stereo systems with two channels. This is also promoted by the fact that significantly more loudspeaker boxes are required, but because of the individual subwoofer, which can be positioned almost anywhere in the room, the remaining loudspeakers of the surround sound system are rather small. Therefore, in order to achieve a very good sound impression, especially in the low-frequency range, medium or large volume hi-fi boxes are no longer required, which, in addition, can only be set up at certain points in relation to the sitting position because of the compliance with the stereo triangle .

The term "Hi-Fi"

From the 1960s onwards, high fidelity or hi-fi indicated that a device (e.g. amplifier) ​​met the requirements specified in DIN 45500. Practically all high-quality electronic devices meet these requirements today; the standard has thus lost its function and was replaced in the 1990s by the European standard, which only specifies the measurement methods.

Today, the term hi-fi in connection with stereo systems rarely includes a quality label. A stereo system made up of high-quality individual components is also called a high-end system . The term “ state of the art ” is rarely used in the hi-fi sector.

High end

The Transrotor company is one of the best-known manufacturers of high-end turntables , some of which cost several 10,000 euros.
While they are practically not used in the normal hi-fi area, horn loudspeakers in the high-priced area are still sometimes used for the mid and high frequency ranges.

The term HiFi claims to be able to reproduce music exactly as it was created by the interpreter and recorded by the sound engineer . Some audiophiles - a name often used in hi-fi specialist magazines for hi-fi and high-end enthusiasts - have spent decades looking for a system that meets these requirements and invest large sums of money in equipment. Five-digit euro amounts for individual components such as a turntable are not uncommon. The term high-end has established itself for this area of ​​hi-fi .

Once a year there is a high-end trade fair in Munich; another in Zurich.

Active components

In the high-end scene there are sometimes lively debates about what constitutes a good system or recording, as the high-end devices, which usually have their own sound, sometimes differ very clearly. In general, within the high-end scene, technical measurement values ​​are found to be largely inadequate to describe the “musicality” of a system, which already indicates that the - actually undesirable, s. u. - specific sound influence by a component plays a role. As a result, often only a part of the measured values ​​of the components is observed or published. In addition, in the high-end industry, no uniform measurement standards, such as those stipulated by the Institute for Broadcasting Technology for radio equipment of the public broadcasting corporations , have been adopted. In order to generate meaningful measured values, however, it is always necessary to specify the measurement method, the reference level and the measurement procedure. The cause of subjectively slightly deviating sound assessments can lie in the non-linearity of the human hearing as well as in psychoacoustic effects, as well as the enormous acoustic influences of the listening room. In the past few decades, the Institute for Broadcasting Technology has undertaken extensive listening tests to determine which measured values ​​must not exceed which limit values ​​so that the audio components in the signal path do not appear in their own way. If audio components move above these limit values, they audibly change the audio signal to be reproduced and thus create their own "sound". Above these limits, the sound experience becomes a purely personal and subjective matter of taste.

Such rendering is said to be "non-neutral". In particular, the sound spectrum (frequency response), the dynamics and the type of non-linear distortion (occurrence of certain harmonics ), and less often the channel separation , play a role. The design of the frequency response (Instrument or channel-specific), the stereo Kanaltrenung and the dynamics responsible for the sound recording already involved recording engineers , sound engineers and the conductors designed consciously and musicians and will. On the other hand, additional harmonics , difference tones and phase errors ( phase response in the frequency range) are undesirable per se, but they play a major role in subjective sound assessment. While many tube amplifiers have relatively high distortion factors, phase errors and differential tone factors can be lower with them than with transistor amplifiers. Bad difference tone measurements lead to disharmonies (additional non-harmonic tones), and phase distortions lead to location errors. These readings can be considered the only real differences - they are easier to achieve with tube amplifiers. A not inconsiderable proportion of high-end fans prefer tube amplifiers and the record , which they consider to be superior in some respects to the newer technologies (especially the digital technology introduced with the CD). The view that these techniques are superior to transistor amplifiers and CD players cannot be proven.

Passive components

Tube amplifiers are audio amplifiers with tubes that are actually obsolete for this purpose instead of the transistors that have been common since the 1970s .

In the area of ​​accessories, attempts are made to improve the sound of the playback chain with additional items such as expensive thick cables made of oxygen-free copper or even solid silver , bi-wiring , bi-amping , and various other components such as gold-plated chassis or specially manufactured capacitors. Most of these measures do not affect the sound or have an insignificant effect on the sound. Some measures are therefore also controversial within the scene and are often referred to as " voodoo ".

The loudspeaker boxes , on the other hand, have a very significant influence on the frequency response, the phase response and the non-linear distortion. Here, careful development by the manufacturer and the use of high-quality components have a decisive influence on the listening experience.


The design of high-end devices and the use of “noble” materials is inherent in the division. Often the design is retro- oriented and the components are consciously shown in their technical function. These include B. the system of electron tubes visible through the glass bulb, including their hot cathodes . The aim is to create long-lasting, valuable products.


  • Robert Harley: The Complete Guide to High-End Audio . 4th edition Acapella Publishing, Carlsbad 2010, ISBN 0-9786493-1-1 .
  • Robert Harley: Introductory Guide to High-Performance Audio Systems. Stereo - Surround Sound - Home Theater. Acapella Publishing, Tijeras 2007, ISBN 0-9786493-0-3 .

Web links

Wiktionary: Stereo system  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Retro stereo system: Test & recommendations (06/20) . February 14, 2020. Accessed June 21, 2020: "Did you know that the forerunners of stereo systems were so-called music chests in the 1950s?"
  2. DIN norm and IHF norm, what is the difference. In: May 21, 2011, accessed August 21, 2011 .
  3. What does audiophile mean? Headphones tested, accessed on May 12, 2020
  4. Impedance & Intelligence. Test: Technics SU-G700 , fairaudio, accessed on May 12, 2020
  5. High End Munich
  6. HIGH END SWISS October 2010
  7. ^ Project "Black Cat" ( Memento from May 10, 2017 in the Internet Archive ) of the TU Berlin
  8. ABX Test Data ( Memento of March 27, 2010 in the Internet Archive ) - test results of blind tests for various components (English).
  9. The wonderful world of hi-fi esotericism , quote: "Classic examples of voodoo in hi-fi devices are, by the way, sinfully expensive amplifiers whose power supply would also do welding devices credit.", May 2, 2016