Sound card

A sound card (also sound card, sound card rare, Eng. Soundcard ), in its own housing also audio interface is the part of the hardware of a computer system which processes analog and digital audio signals. One of the tasks of a sound card will include the recording, synthesis, mixing, editing, and playback of audio signals.

The connection is now (2014) internally via the PCI or PCI Express bus or externally via the USB port, PCMCIA or ExpressCard slot, in the professional field via FireWire. Older sound cards are connected via the ISA bus. Some sound cards support the connection box in a front module (5.25 "slot ) or an external housing, the so-called " breakout box ".

In the 2000s, the typical sound card changed in the course of progressive electronic integration of a physically interchangeable card at a pre - soldered microchip. For users who require a higher standard of sound quality or performance or require extensive connection possibilities, but dedicated sound cards are still in use. However, the performance advantage exists only in sound cards have their own processor as it relieves the CPU.

  • 2.1 Inputs and outputs 2.1.1 analog 2.1.1.1 Microphone Input
  • 3.1 Consumer Cards
  • 3.2 Professional cards
  • 3.3 Onboard Sound Chip

History

First sound cards appeared in 1983 for the Apple II on the market (for example, Mockingboard ), but were still niche products that were only supported by relatively few games. There were pure synthesis cards, play samples was not appropriate to be implemented because of the small memory of that time. In the PC area they became popular from around 1989/90, as developed with the AdLib and Sound Blaster cards first time over and beyond the simple system speaker standard.

Holten, the first models nor the already years before accomplished in the home computer field development in the PC sector after, the sonic capabilities of the PC sound cards were already with the appearance of the Roland LAPC -I, however, also cost about $ 1000, which over the home computer also. This was a major factor in the collapse of the home computer market and the acquisition of market position " computer game " by the previously serving almost exclusively as an office computer PC.

The ISA sound cards of the first generation often have additional IDE connectors for CD -ROM drives, also emerged at this time. In addition to connections for proprietary CD -ROM drives, usually "Sony ", " Mitsumi " and "Panasonic" is often an IDE connector (secondary IDE, IRQ 15, IO base 0x170 ) exists, then what in modern PCs, the are already equipped with two IDE ports, often leads to problems, since now the resources for the second IDE connector must be doubly occupied. Later ISA sound cards without these connections, but are already offering plug -and-play capable. Only one connector for analog transmission of audio signals from CD -ROM drive to the sound card is still present.

The beginning of the 1990s, published the PC sound card Gravis Ultrasound offered hardware mixing with up to 32 hardware output channels and panning on, but could not prevail in the market (except in the demoscene and tracker ). This is because she was the one not fully compatible with the prevailing sound cards, and also because with increasing computing power the cheaper software mixing the Soundblaster cards by set, hardware mixer have since uncommon.

Goods out the most sound cards more or less direct copies of a few common models, this changed after the introduction of Microsoft Windows 95 because Windows - based games did not have to speak directly to the hardware of the sound card, as before, the MS -DOS-based games, but this was done using standardized drivers were hardly set the hardware structure of the map boundaries.

There are many more different sound cards as sound chipsets on the market. Many high-quality sound cards from different manufacturers, for example, use the chipset envy24 which is produced largely unchanged since the late 1990s.

Since about the year 2000, the basic audio functions in most motherboards have been integrated so that separate (dedicated ) sound cards were used only at higher standards of quality and functionality. Meanwhile, even HD audio codecs - such as the ALC888 and the IC manufacturer Realtek ALC889 the - used for the so-called " onboard sound " solutions. If one disregards Creative X-Fi series, and just a few other models from other manufacturers, then these chips are more powerful than the most well-known sound cards and especially as older sound codecs. The weak point in the audio output from the computer are today dar. rather the speakers

Computers are increasingly used for professional music production. Computing power and memory suffice since the late 1990s for signal processing in a relatively cheap computers. The combination of standard PC and high-quality sound card or chipset - has since the previously usual specialized equipment for recording and editing audio in the studio largely displaced. To achieve adequate signal quality of a studio production, sound interfaces are often used that are not built directly into the computer. They are usually connected via a FireWire cable, or by a special PCI card with breakout cable to the computer. By decoupling the audio signals from the rest of the PC and its noise a sound quality is achieved, which is even for specialist applications. For music production, both IBM-compatible PCs and Apple Macintosh computers are. The latter are considered to be particularly optimized for audio processing. For professional use imaginary sound " cards " can be used mostly with both Macs and PCs with.

The manufacturers provide driver software for Microsoft Windows and Mac OS X for both simple and advanced sound cards. Free Projects develop drivers that meanwhile many professional and most simple sound cards can also use with Linux, all functions of the sound card can not be used in some cases.

Examples

1989: Roland LAPC -I sound card for professional users

1991: Creative Sound Blaster legacy ISA sound card with connectors for proprietary CD -ROM drives

1991: Gravis Ultrasound ( in typical red color) with the GF1 chip for hardware mixing

Early 1990s: Oak Mozart 16 sound card, one of the many soundblaster -compatible clone cards

1992: Sound Blaster AWE32 PnP ( ISA PnP sound card)

1993: ISA PnP sound card with FM synthesizer and wavetable synthesis

1995: Yamaha Sound Edge SW20 PC

1996: SEK'D Profif Plus PCI sound card with professional interfaces

1999: Sound Blaster Live PCI sound card, simple execution

2003: CardBus sound card for laptops

2004: HD Audio sound chip for onboard solutions

External USB sound card from Creative

Construction

Based on an audio signal processing in the PC is digitized, an A / D converter, the analog audio signals at the input, and converts a D / A converter, the digital audio signals into analog audio signals at the output. Both transducers are often integrated on the same chip.

And outputs

Inputs and outputs exist in different versions: analog, digital, or via MIDI.

Analogous

There are analog inputs and outputs in the form of output jack or RCA jacks. In modern consumer cards, as well as on ATX motherboards with integrated sound chip or the audio jacks on the front page of modern computers, these jacks are also color-coded to a usually embossed symbol according to international standards (see color code ).

While consumer cards, the phone jacks (except the microphone input) typically designed to route stereo signals in professional cards per jack only a mono signal is transmitted in a symmetrical transmission technology.

Technical data of the audio inputs:

  • LINE -IN: standard level 1 voltage (. Depending on soundcard ± 0.7 volts up to | Uss | max 2 Volts), input resistance 20 ... 70 kOhm
  • MIC IN: maximum input level depending on the sound card of 20 mV max. -100 ... 100 MV ( see also microphone input)
  • LINE OUT: 1 volt standard level (depending on the sound card ± 0.7 volts up to | Uss | max 2 volts, source resistance <50 Ohm to 1 kOhm. )
  • AD / DA converter resolution: up to 24 bit,
  • Sampling rate: variable up to 192 kHz (depending on the sound card)

Sampling rates of 44.1 or 48 kHz for conversion to low-frequency signals ( 20 kHz hearing threshold ) according to the sampling theorem sufficiently - higher sampling rates bring in audio signals barely quality win. General may make sense in the A / D conversion ( digitization ), oversampling, if> 20 kHz are included in the low-frequency signal relevant high proportions because they could not be sufficiently filtered out.

Microphone input

The microphone inputs simple sound card or onboard " sound cards " are not sufficiently sensitive in general to receive signals from dynamic microphones to reproduce ( often below 1 mV) sufficiently well.

After AC'97 standard is behind the microphone input of a 20 dB preamplifier ( voltage gain that is 10-fold ).

Although electret microphones with built-in impedance converter provide sufficient level (some 10 mV), however, need - if they do not have their own power supply - a so-called T-power.

To this end, provides for AC'97 compatible sound card (see AC'97 standard: microphone connector problem) the middle ring of the jack socket of the microphone input via a resistor (about 1 ... 2 kOhm ), a voltage ( 5 volts). The tip of the microphone jack contacts the microphone signal input.

  • Bipolar electret microphones can connect the center ring with the contact at the top (signal input) and work as on the resistance in the PC as a load resistor (see emitter circuit )
  • Electret microphone solutions for better signal to noise ratio seven this often subject to interference voltage first and install your own operating resistance.
  • Mono ( microphone ) jack close the Tonaderspeisung harmless short

The Tonaderspeisung by AC'97 can not serve as phantom power for condenser microphones amplifier due to the low voltage and is connected to 5 volts and less than the T-12 standard ( 12 volt) a "real" T-powering.

Dynamic microphones with stereo plug or jack are balanced not harmed by the current limited to a few milliamps voltage of these T-powering, but typically require an external microphone amplifier.

Digital

Sound cards can have an XLR connector and digital inputs and outputs in an optical or coaxial form in the S / PDIF or AES / EBU format.

MIDI and game port

Some sound cards also include a game port, usually with MIDI connector on the same socket. Data transfer via the gameport works digitally when used as a game controller (eg joystick or gamepad ) analog, when used as a MIDI port. Earlier this game port was present on almost all sound cards, in most modern sound cards it is dispensed with, since newer game controllers are connected to the computer usually via the USB interface and no longer supports Windows Vista from the game port.

USB and FireWire

Good sound quality also allow many external audio interfaces that are connected via USB or FireWire to the computer. Good equipment of this type often also provide high-quality mic preamp, a hardware mixer and in some cases more than eight audio inputs used in parallel and usually an S / PDIF connector for synchronization with another sound card.

Terminal extensions

The limited space on a bracket used on some models with additional cable whips ( a special cable with many connection possibilities, which occupies the joystick port) or a " breakout box " ( an additional module in the form of a drawer for a 5.25 "bay or an external housing ) across.

Sometimes an additional slot bracket is used which is connected inside the housing by means of a cable with connectors on the sound card.

Classification

Qualitatively, converter cards differ by the possible bit resolution (word width, 8 bits, 16 bits or 24 bits ), maximum sample rate (eg 22, 44, 96 or 192 kHz), noise, frequency response, shielding computer internal noise and the maximum number of channels.

Many sound cards support different sound output standards such as EAX, DTS -ES, or ASIO. Normal present-day sound cards also have, in contrast to the board over a variant accelerator chip, the CPU decreases in some computational work. Some cheap soundcards do without it, however.

Consumer cards

Until about the late 1990s, these cards often contained another FM synthesizer chip that allowed the playing of electronic music by sound synthesis and without the use of samples ( digitized sounds ) what computational requirements, and memory usage decreased greatly, but was also less flexible than the sample-based playback. The next step was improving the sound quality of the implementation of a uniform interface for expansion of the sound card using wavetable. Due to ever- increasing computing power and memory size, the FM or wavetable synthesis is carried out today by software means software synthesizers. This FM synthesizer chip as well as wavetable extension option were largely unnecessary.

Professional cards

Professional cards that are used in recording studios and DAW are also referred to as a recording cards. Such cards can usually record several channels separately, which is also useful, for example in drum recordings or recordings of several musicians and sound sources. Basically, you can work full-duplex, ie simultaneously play and record. Also higher- D and D / A converters are used, as in consumer sound cards. Addition, taken into consideration the layout of the board to the specifics of EMC shielded and analog circuits appropriately. The quality of the recorded signal is in this market segment in the foreground; the usual on consumer sound card game port to connect a joystick is not available for professional cards. To the complete avoidance of noise by the electromagnetic fields inside the computer, the D and D / A converter with professional equipment commonly used in external enclosures ( "Breakout Box") can be accommodated.

Frequently exist only in analog and digital inputs and outputs in the S / PDIF format and multi-channel digital audio interface ADAT or (more rarely) TDIF format by which you can connect the card with external converters and digital mixing consoles.

Some models ( such as for professional purposes widespread Pro Tools / TDM ) system and the system of Universal Audio and Soundscape also have DSP chips which allow the complete processing and mixing together the data streams including a complex effects directly on the map and thus the main processor of the computer not strain. The cards can thus operate fully autonomously; the effects and the mixing settings are only set by the PC software.

Onboard sound chip

First attempts to integrate on ia32 -compatible motherboards a sound chip in the late 1990s, have been made. This is to motherboards with the Super Socket 7 AMD K6 -2 processors or the Slot 1 for Intel Pentium II processors. These sound chips are logically to ISA PnP devices, their configuration sometimes turns out problematic. The functionality of these first sound chips is limited to stereo audio playback and microphone inputs for high level and, in particular, the microphone input is practically not usable often due to strong noise. The recording and playback quality can be set for a maximum " stereo 44.1 kHz 16 - bit". In addition, a MIDI-/Gameport-Schnittstelle is provided. Since about the year 2000, the basic features of sound cards are increasingly often provided by a sound chip on the motherboard. These sound chips are logically to PCI devices, what the configuration with respect to the ISA PnP variant usually somewhat simplified. Initially, this PCI sound chips did not offer more functionality than the PnP version. With time, however, more features have been added and improved the signal - to-noise ratio as well. News can be found on the motherboards usually sound chips, which offer 7.1 audio playback and inputs for S / PDIF, high-level and microphone. The previously common MIDI-/Gameport-Schnittstelle is, however, ceased to exist.

Manufacturer (selection)

  • AdLib
  • Asus
  • Club 3D
  • Creative Labs
  • Grave accent
  • Guillemot Corporation
  • Nvidia
  • Philips
  • Realtek
  • TerraTec
  • VIA Technologies

Pictures of Sound card

Sound card # Sound card # Sound card # Sound card # Sound card # Sound card # Sound card # Sound card # Sound card # Sound card #
Analogsignal Audiosignal IEEE 1394 Industry Standard Architecture Ad Lib, Inc. Intel High Definition Audio Computer memory IBM PC compatible Oak Technology Clone (computing) PC Card Foundation (engineering) Soundchip Decibel Fanout cable Environmental Audio Extensions DTS (sound system) Audio Stream Input/Output Digital Audio Workstation Avid Audio Line 6 (company)
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