【 Weak current College 】 professional audio card selection (1)

Multimedia PC sound card as a sound source and audio processor, an audio signal from audio volume control circuitry within the adjusted to the multimedia power amplifier input interface, zoom so driven speaker. The sound card in the PC system status has become increasingly important, the sound quality is good or bad will increasingly be the player to the PC sector also appeared in the so-called "Hi-Fi".
1. the functions of your sound card
CD music (CDAudio) recording to WAV file, convert the AAS DAS (that is, A/D conversion) is one of the main functions of your sound card. In theory, sound card sampling frequency (now mostly achieved 48KHz) and sampling precision (now almost entirely 16bit) higher, more access to better conversion results. By mixer (Mixer) for different audio sources according to user requirements for the management and operation, such as control CD, Microphone, MIDI and audio sources such as Line-In playback volume and balance of left and right channels, control the recording volume, mixed recording or playback, try to mimic the sound you want. As PC surround sound (such as the latest pop EAX and A3D) appear and the other special effects (like ECHO), and other functions, the sound card you want to have the appropriate audio chip for hardware accelerated processing, otherwise it will significantly increase the CPU load, affects the system overall speed.
AC (AudioCodec) 97 ' is Intel Corporation 1997 launch of specialized industry standards for audio and design specifications. Which provides audio a/d and D/A conversion and Mix audio mixing operations to separate codec (Coder-Decoder) chips, and separate audio chip, with the aim of improving the audio signal to noise ratio (SNR, SignaltoNoiseRatio), separate the above work to reduce chip mutual interference.
Now available on the sound card in the newer standards are in accordance with AC97 ' design. But with AC97 ' standard does not mean that you must be PCI sound card, many ISA sound card is also compatible with AC97 ' standard, since 1997, PCI sound card also is rare, but the latter development quickly, has become the mainstream of domestic areas.
2. main characteristics of the sound card and performance
2.1 interface
Using PCI interface card product, its technical performance than ISA sound cards are strong, specific refer to the resolution of the professional sound card. With PCI interface, sound card can achieve more technical features, he can use Wavetable samples stored in the system's hard drive, with high bandwidth PCI implementation that is used is taken so that the cost of wavetable sound card dramatically reduced. Plug connection, PCI sound card than ISA sound much better, and will not be affected by such as interrupt allocation problems. While PCI sound card system resource consumption rate of only 10%-15% while the General ISA sound card consumes 30% so that the system has more time to deal with other matters, in efficiency but also on PCI sound card with many times higher.
2.2 high-quality sound and a high signal to noise ratio
PCI sound card generally have a higher signal-to-noise ratio (which most can be easily achieved 90dB) to ensure that the output of the voice timbre more pure, noise reduced to a minimum. But the tone is good or bad depends on the product selected sound chip and work (good wiring and connector materials can effectively avoid external signal interference). If possible, it is a good idea to purchase a sound card to audition before the ear to sound judgement will always be the most accurate.
2.3MIDI synthesis effect
One of the benefits of PCI sound card is you can use the advanced technology of DLS (DownLoadedSound), Wavetable sound stored in the hard drive, sound card, chip handling, helping the play MIDI into memory. This not only provides good MIDI synthesis effect and can remove ISA Wavetable sound card must be equipped with sound library memory, reduce production costs. In additionto the large volume of wavetable synthesis, MIDI effect also depends on the wavetable sound card chip the maximum supported number of complex (complex number that is the sound card can at the same time the number of pronunciation). The more complex number, when you play MIDI music hear voices. If MIDI music of polysyllabic than sound card number of the most complex, you will lose some of the voices.
2.43D audio support
In the ISA era many advertised "3D sound effects" of the sound card, but because the ISA interface audio bandwidth is relatively small, its processing and playback capabilities of three-dimensional sound effects are very limited. The current PCI sound card product of 3D sound support is divided into two camps, A3D (AurealSemiconductor developed ground-breaking interactive 3D positioning sound technology) and EAX (EnvironmentalAudioExtensions environmental sound expansion set, the main responsibility is to the game's 3D reverb effect). A3D technology claims as long as 2 to create the only speaker of 3-d effects (4 speakers, of course, better), and EAX you must have 4 speakers in order to have good performance. In addition, there are also using CRLs company Sensaura technology three-dimensional sound effects processed, but the effect is not very satisfactory.
3. the mainstream products
The sound card's core is a sound chip, you can say that the sound card's basic features and quality depend on sound chip, determine product quality. With the PCI bus to flourish and the decline of the ISA bus, this transformation also includes the sound chip. Because the PCI bus operating frequency and bandwidth is greatly improved, if still use ISA sound card chip certainly does play its effectiveness.
Now many of the sound card on the market, but the use of chip number is the same, now describes the commonly used PCI sound card and audio chip performance parameters to select. [fenye]
3.1 innovation company CreativeSBLive! and SBLive! Value
CreativeSBLive! is currently the best acoustic performanceCard, using the EMU10K1 chip high speed sound processing. Supports 2-way 4 speaker output, by attaching the daughter card can have a S/PDIF input/output functionality while supporting future 7.1 speaker output, support for innovation development of EAX environmental sound. SBLive! Value is a simplified version of SBLive!, just get rid of a digital add-on daughter card interface, functionality and price relatively more approachable. In signal to noise ratio, SBLive! series is a 120dB, feeling really good when used.
EMU10K1 chip with innovative CT1297-TATCodec chip. He uses the 0.35 μ m manufacturing process, the integration of more than 200 million transistors, it can achieve 1000MI/s operation capability (equivalent to a regular Pentium processor). The main technical features are integrated into the development environment E-mu sound technology (EA: EnvironmentalAudio), E-mu 4 sound simulation technologies and harddisk recording combination function in Darwin. Therefore in a sense, he is not a general sound chip, but with a certain professional level, specific performance may refer to the analysis of professional sound card ". The end of March 1999, the innovative company has introduced the latest EAX3.0 environmental sound API, with EMU10K1 hardware acceleration will put the EAX mentioned higher performance levels.
ES1370, ES1371 and Creative5507 chip for innovative EnsoniqAudioPCI (SoundBlasterPCI32), SoundBlasterPCI64 and SoundBlasterPCI128, of which the first two from Ensoniq companies (merger by innovation). These three chips are only 32 hardware complex, which is available through the PCI128 PCI64 and corresponding software Wavetable extended to 64 and 128 tremolo, and can use the 4-8 MB of samples download space. Their support for DirectSound and DirectSound3D, available through software upgrades, support EAX, EAX, however only compatible, 3D surround and environmental sound part because chip different cannot support. But has been able to truly support Creative5507 4-channel surround output, but it is through software ES1371 simulations to produce 4-channel output effect. It is not difficult to see, Creative5507 overall performance better.
3.2 dimeng MonsterSoundMX300/SonicIMPACTS90
MX300 adopts AS (AurealSemiconductor4) company integrates 330 million transistors Vortex2AU8830A2 processing chip, and have the latest A3D2.0 processing functions. He supports 2-way 4 speaker output, you can automatically forward 2 speaker simulation into 4 speaker output. Similar with SBLive!, MX300 can also be accessed via MX-Link extension interface, enabling S/PDIF output, and support 5.1 speaker out, adjust the software also supports bass Equalizer fine adjustment. MX300 tend to provide high quality and accurate A3D sound output, in-game voice performance can result in more realistic effect. The S90 is dimeng mid-range sound card in one of the best product, he adopts AurealAU8820B2 chip supports A3D sound effects, in the compatibility and the timbre of the input and output is very good, but the MIDI playback of layered slightly less, and only supports 1 to speakers. But overall, the price of your sound card, the S90 is undoubtedly one of the most worthy of purchase payment.
Vortex-1 (AU8820) chip is the most used one chip. He features full support for the development of the company AS A3D1.0 standard, with 64 hardware tremolo and support DLS, you can use up to 4 MB RAM storage Wavetable samples. The chip itself SNR 90dB, if combined with higher than the corresponding software, can also be DolbyDigital (AC-3) decoding operation. In addition, AS the company has also added new AU8820 SoundBlaster/Pro simulation technology, which can effectively support the DOS environment. But AU8820 also supports MPU-401, can be directly connected with the ISA bus Modem chip for the extension and, if necessary, can also be external Motorola, Inc. (Motorola) 56011DSP chip for faster decodingspeed. Use Vortex-1 chip typical products is on the SonicImpactS90 Dimeng A3D support more than other compatible products.
Vortex-2 (AU8830) chip is AS our new within the 1s handles 600M instruction (600MI/s), with 320 tremolo (64 to hard wavetable, 256 soft Wavetable), support the DLS and 4MB Wavetable sample memory, supports up to 96 DirectSound channel, effectiveness is AU8820 theory 2 times higher than that of 96dB, SNR. Vortex-2 can add 4 Codec and 1 ModemCodec, and can be upgraded through the daughter card to DolbyDigital (AC-3) decoding, scalability is strong. In addition, only he will support the latest A3D2.0 audio surround technology (A3D mentioned above are 1.0 version), with sound tracking capability (WaveTracking) and with the same environmental material EAX set/response and the ability to add 4 speakers to the current best A3D effect. Dimeng of MonsterSoundMX300, TurtleBeach M o n t of e g o Ⅱ and Xited of StormPlatinum sound card.