do you mean your DELL U2713HM is connected through DVI or VGA since it support DP and HDMI ?
CONNECTIVITY 1 Dual Link Digital Visual Interface connectors (DVI-D) with HDCP 1 DisplayPort 1.2 (DP) 1 High Definition Multimedia Interface (HDMI) 1 Video Graphics Array (VGA)
you have to post the output of alsa-info.sh and xrandr --verbose
do you mean your DELL U2713HM is connected through DVI or VGA since it support DP and HDMI ?
CONNECTIVITY
1 Dual Link Digital Visual Interface connectors (DVI-D) with HDCP
1 DisplayPort 1.2 (DP)
1 High Definition Multimedia Interface (HDMI)
1 Video Graphics Array (VGA)
you have to post the output of alsa-info.sh and xrandr --verbose