Antex electronic SX-5e, SX-6, SX-34, SX-36 user manual ISO/MPEG-1 Bitrates

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a file, but no fading. Some audio editing programs do edit MPEG files, but they actually convert the file to PCM16 first, and then convert it back again after editing. This has two problems. First, it is slow, and second, each time the conversion is done, the sound quality is degraded. MPEG is only valid for 32, 44.1 and 48 KHz. MPEG requires a great deal of DSP processing power. As a result, the SX-36 can record a 32 KHz MPEG file and play an- other 32 KHz file back at the same time, but not 44.1 or 48 KHz MPEG files. The SX-34 or SX-36 can simultaneously record and play back 48 KHz PCM16 files.

ADPCM is typically 4 to 1 compression, however, lower sample rates are possible. Therefore, an ADPCM file recorded at 8 KHz will use half the disk space of an MPEG file recorded at 32 KHz with 8 to 1 compression. The sound quality will be much worse, but if the application is to record a conversation for archive pur- poses, the sound quality may be adequate. ADPCM is also easier to edit.

In a network environment, where all sound files are stored on a server and sent to the individual computers via a network, the data rate is an issue of concern. If the network cannot send the data from the file on the server to the computer fast enough, there will be objectionable “dropouts” or “pops and clicks” in the audio. Using a compressed file format will allow for more network traffic before this problem occurs. Also, compressed file formats are advantageous if the files must be sent by modem or emailed somewhere.

ISO/MPEG-1 BITRATES

ISO/MPEG supports several compression bitrates. (The bitrates in the Antex Demo program are selected by double-clicking on MPEG in the Compression list to get a bitrate drop-down menu)

MPEG-1 has a range of compression ratios that are user select- able. The compression ratio selected will depend upon the audio quality required. The MPEG-1 format specifies the compression ratio by defining the desired bitrate. The compression ratio ob-

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Contents Th Street September 17 Rev. EAntex Electronics Corporation GARDENA, CaliforniaDeclaration of Conformity Table of Contents SX-34 Mixer and Block Diagram SX-6 Mixer and Block Diagram Figures Card Installation IntroductionJumper Settings & Connections SX-5e,6,34,35 & SX-36 Jumper SettingsAddresses and Interrupts Making Connections to the CardPage SX-35/36 Connector Description SX-35/36 ConnectionsLine I/0 JP8 AUX in JP9 MIC JP7SX-34 Connector Description Output Header JP5AUX Header JP6 Microphone Header JP7Mono Header JP4 SX-6 Connector Description SX-6 ConnectionsLine OUT JP2 Microphone Input JP3SX-5e Connector Description Balanced and Unbalanced SignalsImpedance and Signal Levels Playback and Record Devices COMPRESSION, Data RATES, and Networks ISO/MPEG-1 Bitrates 32 KHz 44.1 KHz 48 KHz Driver Installation Windows Setup Tips Upgrade Driver, WINSetup Tips Upgrade Driver, WIN Windows NT Antex Application Software Installation Using Windows Demonstration Software Sample RateCompression Mpeg BitratesVU Meters ChannelsWave Device File Record/StopInstalling and Using Multiple Cards in a System VolumeDual Device Operation Mixer and Block Diagrams SX-36 Mixer and Block Diagram Page Page SX-36 Mixer SX-36 Block Diagram SX-34 Mixer and Block Diagram SX-34 MixerSX-34 Block Diagram SX-6 Mixer and Block Diagram SX-6 Mixer SX-6 Block Diagram SX-5e Mixer and Block Diagram SX-5e MixerPage SX-5e Block Diagram Antex Meter Antex MeterAntex Meter pull-down menu Antex Meter options Page Troubleshooting Files I record sound dull Files recorded are of poor quality There are dropouts or pops and clicksTECHNICAL/ORDERING Information Toll Free 800 Phone 310 FAX 310Appendix Connectors for Male HeadersTerms Page All Cards as applicable SpecificationsSX-36 SX-34 SX-6SX-5e About Digital AudioPage Analog-to-Digital Digital-to-Analog
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