What sort of cable should I use for digital connections?
There are two types of digital connection used in GENELEC monitors: AES-EBU and S/P-DIF. Note that S/P-DIF connection has only been used on the 2029A monitor - now discontinued. As far as cabling is concerned the following requirements must be met for reliable operation:
S/P-DIF
| Characteristic impedance: | 75 Ohm |
| Cable type: | Cable intended for S/P-DIF digital audio transmission |
| Connectors: | RCA - RCA |
| Maximum cable length: | Determined by cable losses, recommended maximum 10 meters |
AES-EBU
| Characteristic impedance: | 110 Ohm |
| Cable type: | Cable intended for AES-EBU digital audio transmission |
| Connectors: | XLR (male) - XLR (female) |
| Maximum cable length: | Determined by cable losses, recommended maximum 100 meters |
Do not use standard audio cable or microphone cable as you should use a high-grade digital signal transmission cable. A proper digital cable is specified by its characteristic impedance (ohms), loss per meter (dB/meter) and radiation attenuation (dB). Use only cable designed to carry the signal you want, as there is a special cable available for AES-EBU digital audio signal but there are several types of high quality 75 Ohm coax cables available for S/P-DIF.
Cable losses per meter, which should be as low as possible, determine how far you can carry the signal. Cable radiation attenuation determines how much noise your digital audio signal will radiate to environment and also how susceptible your system is to other localized electronic noise sources. Good attenuation of noise interference will make your system more robust and will deliver higher quality over a longer distance. In practice, you will not see any (significant) degradation in audio quality until your signal quality drops below a certain level. To determine how well your transmission system is working above this level you need special analyzers to measure the quality of the digital audio signal. If you plan to carry the digital audio signal over long distances it is advisable to use these tools to make sure you know how well your system is working and what should be corrected.