Audio Hardware - Connectors for Advanced Features
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Many of the newest sound cards and motherboards with onboard sound are designed for advanced gaming, DVD audio playback, and sound production uses and have additional connectors to support these uses, such as the following:
MIDI in and MIDI out. Some advanced sound cards don't require you to convert the game port (joystick port) to MIDI interfacing by offering these ports on a separate external connector. This permits you to use a joystick and have an external MIDI device connected at the same time. Typical location: external device.
SPDIF (also called SP/DIF) in and SPDIF out. The Sony/Philips Digital Interface receives digital audio signals directly from compatible devices without converting them to analog format first. Typical location: external device. (SPDIF interfaces are also referred to by some vendors as "Dolby Digital" interfaces.)
Note - SPDIF connectors use cables with the standard RCA jack connector but are designed to work specifically at an impedance of 75ohms—the same as composite video cables. Thus, you can use RCA-jack composite video cables with your SPDIF connectors. Although audio cables are also equipped with RCA jacks, their impedance is different, making them a less desirable choice.
CD SPDIF. Connects compatible CD-ROM drives with SPDIF interfacing to the digital input of the sound card. Typical location: side of audio card. The cable used resembles the cable shown in Figure 16.2, but it uses only two wires. See Figure 16.10, later in this chapter, for an example of a typical sound card using a CD SPDIF cable.
TAD in. Connects internal modems with Telephone Answering Device support to the sound card for sound processing of voice messages. Typical location: side of audio card.
Digital DIN out. This supports multispeaker digital speaker systems, such as those produced by Cambridge for use with the SoundBlaster Live! series. Typical location: external device.
Optical SPDIF in/out. This supports home theater and digital speaker systems with optical inputs. Typical locations: rear of card or external device.
Aux in. Provides input for other sound sources, such as a TV tuner card. Typical location: side of audio card.
I2S in. This enables the sound card to accept digital audio input from an external source, such as two-channel decoded AC-3 from DVD decoders and MPEG-2 Zoom Video. Typical location: side of audio card.
USB port. This enables the sound card to connect to USB speakers, game controllers, and other types of USB devices. The Hercules Game Theater XP series, the first sound card with built-in USB ports, supports USB 1.1 only. Typical location: external breakout box.
IEEE 1394. This enables the sound card to connect to IEEE 1394–compatible DV camcorders, scanners, hard drives, and other devices. The Creative Labs Sound Blaster Audigy, Audigy 2 series, and Hercules Digifire 7.1 all feature one or more IEEE 1394 ports. Typical location: card bracket or external cable or breakout box.
Sometimes, these additional connectors are found on the card itself, or sometimes they are attached to an internal or external breakout box, daughtercard, or external rack. Currently, the Sound Blaster Audigy 2 ZS Platinum and Platinum Pro sound cards from Creative Labs are two-piece units. Other recent models that feature a similar design include the Audigy 2 Platinum EX, Audigy 2 Platinum, Audigy Platinum, and the Hercules Game Theater XP 6.1 and 7.1. Although details vary, each of these models features a PCI-based sound card with basic I/O ports and a separate component with additional and more advanced I/O ports. The Audigy 2 ZS Platinum routes its additional connections to an internal breakout box that fits into an unused 5 1/4'' drive bay (see Figure 16.3). The top-of-the-line Platinum Pro uses an external breakout box with the same connection options. Both models feature a remote control (not shown) and external volume controls (visible in Figure 16.3). The Hercules Game Theater XP series also featured an external breakout box, which Hercules refers to as an audio rack.
Figure 16.4 shows Chaintech's AV-710 audio adapter card with the internal connectors common on today's 3D sound cards.
Figure 16.3 The Sound Blaster Audigy 2 ZS Platinum (left) includes the Audigy 2 ZS Drive internal, front-panel breakout box (right) to support the Audigy 2 ZS's many features.
Figure 16.4 Chaintech's AV-710 is a typical example of a mid-range 3D sound card with 7.1 audio support.
Adding Advanced Sound Features Without Replacing Onboard Audio Traditionally, audio card upgrades have been designed specifically for users of desktop computers, leaving the growing number of notebook computer users out in the cold if they decided that the bare-bones features of their integrated audio weren't sufficient. However, several companies have recently developed USB-based audio processors that can be used by both notebook and desktop computers.
When you consider a USB-based solution, keep in mind that, unlike a normal sound card upgrade, you don't need to disable your existing onboard sound or remove a sound card. USB-based audio can coexist with existing sound cards. Typically, as with most hardware, the most recently installed hardware in a category becomes the default, but you can switch back to the original audio hardware through the Windows Control Panel Sound properties sheet.
Beyond the ability to add audio to almost any recent system, USB-based audio is particularly appealing if your current sound card or onboard audio doesn't support 5.1 or 7.1 audio, can't digitize sound at 24-bit/96KHz rates, or lacks digital outputs. Table 16.1 lists the major features of current and recent USB-based audio products.
Table 16.1 USB-Based Audio Processors
Manufacturer | Product | Output Quality | Recording Quality | Speaker Support | Notes |
Audiotrak | MAYA EX | 16-bit/48KHz | 16-bit/48KHz | Up to 5.1 | Dolby Digital AC-3 |
Audiotrak | MAYA EX7 | 16-bit/48KHz | 16-bit/48KHz | Up to 7.1 | Dolby Digital AC-3 |
Creative Labs | Sound Blaster Extigy | 24-bit/96KHz | 16-bit/48KHz | Up to 5.1 | Dolby Digital AC-3 |
Creative Labs | Sound Blaster MP3+ | 16-bit/48KHz | 16-bit/48KHz | 2.1 | Optical SPDIF input/output |
Creative Labs | Audigy 2 NX | 24-bit/96KHz | 24-bit/96KHz | Up to 7.1 | Dolby Digital AC-3, EX; supports Hi-Speed USB |
Hercules | Gamesurround MUSE Pocket | 16-bit/48KHz | 16-bit/48KHz | Up to 5.1 | No SPDIF connector |
M-Audio | Sonica | 24-bit/96KHz | N/A | Up to 5.1 | Dolby Digital AC-3 with optical output only |
M-Audio | Sonica Theater | 24-bit/96KHz | 24-bit/96KHz | Up to 7.1 | Dolby Digital AC-3 |
Philips | PSC805 Aurilium | 24-bit/96KHz | N/A | Up to 5.1 | Dolby Digital AC-3; supports Hi-Speed USB |
TerraTec | Aureon 5.1 USB | 16-bit/48KHz | 16-bit/48KHz | Up to 5.1 | Dolby Digital AC-3 |
The connectors and controls on the Creative Labs Sound Blaster Audigy 2 NX are shown in Figure 16.5.
Before you purchase a new sound card or USB-based audio solution for a desktop computer, you should check your system or motherboard documentation to see whether you already have six-channel audio onboard. If your motherboard features six-channel (5.1) or better audio output but the only ports built in to the rear of the motherboard are for a normal stereo (2.0/2.1) configuration, you need to add a header cable to the motherboard similar to the one shown in Figure 16.6. If the motherboard did not ship with the header cable, contact the vendor.
Figure 16.5 The Sound Blaster Audigy 2 NX expands bare-bones onboard audio by adding advanced I/O and sampling features similar to those found on the Sound Blaster Audigy 2 series.
Figure 16.6 The built-in ports on the ATX port cluster (left) support stereo output, but the header cable (center) adds support for four-channel and six-channel audio and digital sound.
 | This chapter is from Upgrading and Repairing PCs, 16th edition,by Scott Mueller. (Que Books, 2004, ISBN: 0789731738). Check it out at your favorite bookstore today. Buy this book now! |
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