Connecting Eclipse to Computer Sound Cards (only aviliable in english)

This application note describes the use of Eclipse in IP conference applications. Eclipse’s echo cancelling abilities allow for full duplex conferencing via IP networks and this application note describes the connection of Eclipse and required adjustment and tuning. This document does not describe the installation and use of the IP conference application itself neither the installation and configuration of the sound card. We highly recommend you to use a sound card of high quality to avoid any cross talk or echo appearing in the sound card itself.




Cable
In order to connect Eclipse to a soundcard, a special cable must be made. See diagram below. This cable may also be ordered from Gemini – order GC1116 – PC Cable, Type J.






Please note that pin 1 and 4 on the Eclipse connector are connected to the Line In connector on the sound card, while pins 2 and 3 are connected to the Line Out connector on the soundcard. Polarity doesn’t matter as balanced signals are used.




Where to connect the jacks?
Most soundcards are equipped with the following connectors:

Input: LineIn and Microphone

Output: LineOut and Speakers (some soundcards are equipped with outputs for both rear speakers and front speakers.

For best performance, it is preferred that Eclipse is connected to the Line Out connector in stead of the speakers connector on the soundcard. (If you want to try the speakers output, with somewhat stronger signal, make sure you use the front speaker connector, where both front- and rear speaker connectors are available).
Moreover, it is recommended to use the Line In connector in stead of the microphone connector. This because the microphone connector in many cases may add unwanted noise to the signal. Also, in many cases the Microphone input is furnished with an AGC (Automatic Gain Control) function, which in some cases may cause trouble for the Eclipse Line Echo Canceller circuitry.

Some Internet communications software, such as Microsoft NetMeeting, seems to automatically select the Microphone as input (in stead of Line In). If you are forced to use the microphone input, make sure that you disable AGC and MicBoost functions, if possible. See your soundcard documentation for details.

Tip: Right Click the loudspeaker icon on the taskbar, and select Open Volume Controls. In the mixer window choose Options and Properties. Then in the properties window select Adjust volume for Recording. In the new Mixer Window click the Advanced button. In the Advanced Panel appearing you can select and deselect such properties.

Tuning
First, in order to operate, the Eclipse must be programmed to operate in "Always On Mode". See the Eclipse documentation for the proper procedure. For optimum performance it is important that the levels are set correctly. The settings may vary depending on the type of soundcard you are using. Repeated testing and experience will help. The following procedure will be a good starting point:

1. Adjust the sound card Main Volume to middle position

2. Adjust the soundcard Wave Volume to maximum position

3. Adjust the LineIn/Mic Volume in the recording panel to medium position

4. Adjust the Eclipse to maximum loudspeaker volume by pressing Volume Up on the Remote Control Unit

5. Adjust the Phone In level on Eclipse so that you can hear the other party at a satisfactory level

6. Adjust the Phone Out level on Eclipse so that the other party can hear you at a proper level

Important: Make sure that no one changes the mixer settings on the computer after this tuning procedure has been completed.