10
Improving Direct X Speakerphone Performance and Quality
Important:
This section applies only to Data/Fax/Speakerphone driver builds using
soft-speakerphone implementations. These drivers use Windows Direct X and the PC sound system
instead of dedicated voice hardware on the modem board (i.e. instead of voice codec and speaker
and microphone jacks on the modem board).
The following sound system tuning can be done via the Windows Master Volume control -- double
click the speaker icon in the Windows system tray. Please be aware that different sound systems
have different configuration options, so not all volume and recording windows look the same or
provide you with the same options. Or indeed some of the window and control names can be
different.
Master Volume Control
(Playback/Speaker)
All balances should be muted except for the "Wave Balance" and the "Volume Control Balance".
Recording Control
(Recording/Microphone)
The only balance selected should be the "Mic Balance". All the other should not be selected or
muted depending on the selections given (somewhat sound system dependent). To be sure, it is also
recommended to keep the levels of the unselected balances in the recording control window to
minimum setting. Also in case the Microphone gain is too low (rarely) then you can always boost it
up by a multiple of 10dB by going to "Options" and to "Advanced Controls" and clicking on the
"Advanced" icon. In the "Advanced Controls for Mic" window check the boost box and close the
window to boost the mic level.
Conversely, if the gain of the mic is too high and you talk too close to the mic, then the voice will be
saturated and noisy. If this is the case deselect the "Mic Boost" check box.
11 Contact
Information
If you have a problem with the SM56 modem, ensure that the problem and its solution are not
shown in the Troubleshooting section. If you cannot resolve it through this list first contact your
direct SM56 modem or PC supplier.
Modem related information should include as much detail as possible to allow support teams to
qualify and reproduce (if necessary) the problems, including:
Information about your modem:
•
SM56 modem driver version number (find this by recording the modem's response to the
ATI3
command)
Information about your setup:
•
The telephone number you are calling from.
•
The telephone number you are calling to.
•
If performing a lab test, a detailed description of the equipment used.
•
The remote modem information.
•
Direct external analog telephone line or through a PBX -- use direct analog lines where
