Troubleshooting: Common Dante Audio Issues

This guide covers discovery failures, silent subscriptions, dropouts, clock errors and AES67 on KanexPro's AUD-DTE Dante adapters and amplifier: the AUD-DTE-ECODE encoder and AUD-DTE-DCODE decoder; the AUD-DTE-LINEIN, AUD-DTE-LINEOUT, AUD-DTE-XLRIN and AUD-DTE-XLROUT analog adapters; the AUD-DTE-USB, AUD-DTE-USBC, AUD-DTE-HDMI and AUD-DTE-BT digital-source adapters; and the AUD-DTE-2CHAMP amplifier. Dante routing for all of them is done in Audinate's Dante Controller.

Quick reference: level controls and power

Discovery

Why doesn't the device appear in Dante Controller?

Check the network link first, then that the Dante Controller computer is on the same subnet as the device and is using the right network interface.

1. Link. On the AUD-DTE-ECODE, DCODE, LINEIN, LINEOUT, XLRIN, XLROUT, USB, USBC and BT, the green LINK LED on the DANTE port should be on. On the AUD-DTE-HDMI, check the link light on its switch port. If there is no link, check the cable (CAT6 or CAT6A, wired straight-through rather than crossover, no longer than 100m/328ft) and that the switch port supplies PoE 802.3af Class 0. If it does not, use the backup power listed above. Try a different cable or switch port.
2. Subnet. Dante Controller can typically only discover devices in its own IP subnet. Put the computer on the same subnet as the Dante devices. A system that spans subnets or VLANs needs Dante Domain Manager (see the DDM guide below).
3. Interface and addressing. Check which network interface Dante Controller is using (the interface selection button in the Network View toolbar). Dante devices take an address from DHCP if a server is present, and otherwise assign themselves a link-local 169.254.x.x address. Set the computer to obtain an address automatically, and avoid mixing DHCP and link-local addressing on one network. The Device Info tab lists every device's IP address.
4. Reboot with care. Restart Dante Controller, then reboot the unit. On the AUD-DTE-XLRIN, XLROUT, LINEOUT and USBC, RESET only reboots the unit. On the AUD-DTE-LINEIN, holding the recessed RESET button for 5 seconds restores factory defaults and drops its subscriptions. On the AUD-DTE-HDMI, the reset button resets its Dante settings.

No audio

Why is the device visible but passing no audio?

Check the subscription, then the sample rate, the clock and the levels. In Dante Controller's Routing view, a green tick at the cross-point means the subscription was created, and a warning or error icon means there is a problem — hover over the icon for the reason. A grey square instead of a blue one means no route is possible, which can be a sample-rate mismatch between transmitter and receiver.

• Sample rate. Set transmitter and receiver to the same rate in Device View > Device Config (48kHz is the AUD-DTE-LINEIN default). The AUD-DTE-ECODE, DCODE and USB support 44.1, 48 and 96kHz, not 88.2kHz. The AUD-DTE-BT's Dante output is 48kHz.
• Clock. A red mute icon in the Clock Status tab means the device is muted, usually because it has lost clock sync — see the clock question below.
• Data LED. On the AUD-DTE-ECODE, DCODE, XLRIN, XLROUT, USB and USBC, the yellow DATA LED on the DANTE port flashes during transmission. On the AUD-DTE-LINEOUT, the yellow DATA LED indicates data transmission, and on the AUD-DTE-LINEIN the amber ACT LED indicates data activity.
• Levels and wiring. Check the level control for the model in the table above. On Phoenix connections, balanced wiring uses +, − and GND, and unbalanced wiring uses + and GND. If an input adapter distorts or clips, its sensitivity is most likely set too low for the source: on the AUD-DTE-LINEIN or XLRIN, turn that channel's knob towards position 1 (+24dBu) until the clipping stops. As starting points on the AUD-DTE-LINEIN, use position 2 (+4dBu) for a professional mixer and position 5 (−10dBV) for a consumer device. On the AUD-DTE-ECODE, set the GAIN switch to the source's output level: +18dBu for professional balanced outputs, 0dBu for standard line level, −10dBv for consumer level. On an output adapter, set the gain to match the destination's input sensitivity and no higher than that equipment's maximum input level.
• Digital sources. On the AUD-DTE-HDMI, the HDMI LED should be solid green (flashing means it is booting), and the source must output PCM 2CH. Select the AUD-DTE-USB as the audio device in the operating system or application. Connect the AUD-DTE-USBC by its USB-C (Audio) port. A STATUS LED flashing at 1Hz on the AUD-DTE-BT means it is unpaired and discoverable: short-press PAIR and pick it from the source's Bluetooth list.

Why is there no speaker output from the AUD-DTE-2CHAMP?

Check the SPEAKER switch and the output terminal first. The rear-panel SPEAKER switch must match the load — 4/8Ω for low-impedance speakers, 70V/100V for constant-voltage lines — and the speakers must be on the matching output: the 4/8Ω AMP OUT or the 70V/100V AMP OUT, both 4-pin 5.08mm locking Phoenix.

• Input. Confirm the active input is the one carrying audio: Dante (the default) or Line. The command s input 2 selects Dante, s input 1 selects Line, and r input reports the current source.
• Volume. Check that the master and output volumes are not muted or at zero. Over RS-232 (115200 baud, 8-N-1), s master vol x sets the master volume (0–100).
• Trigger. A 5–12V signal on the TRG pin mutes the amplifier; removing it restores audio.
• Standby. Check the auto standby setting (0–120 minutes).
• PROTECT LED. If it is lit, the amplifier has gone into protection for overtemperature, overcurrent or overvoltage. Power off, let it cool, check the speaker wiring for shorts or an impedance mismatch, and confirm the SPEAKER switch setting.
• Subscription. Confirm the amplifier's Dante receive channels are subscribed to the right transmitter and show a green tick.

Dropouts and clocking

What causes audio dropouts or glitches?

One cause Dante Controller shows directly is late packets: a receiver discards packets that arrive after its latency setting allows, and that is heard as glitches. Where the device supports latency monitoring, the Latency tab in Dante Controller shows it: amber bars mean packets are arriving near the limit, and red bars mean late packets and lost audio. Raise the receiver's latency or fix the network.

• Latency. The AUD-DTE-LINEIN, LINEOUT, XLRIN, XLROUT, USBC, HDMI and BT offer 1, 2 or 5ms. KanexPro's guidance is 1ms on a single-switch network and 2–5ms on multi-switch or larger networks. If transmitter and receiver are set differently, Dante uses the higher of the two.
• Energy Efficient Ethernet. Disable EEE (“Green Ethernet”, IEEE 802.3az) on every switch port carrying Dante. It can cause poor synchronisation and occasional audio dropouts, and Dante devices mute when clock sync fails.
• QoS. Configure QoS on the switches carrying Dante. The AUD-DTE adapters connect at 100Mbps, and Dante requires QoS on any network with 100Mbps or mixed 1Gbps/100Mbps equipment, even one carrying only Dante audio; it is also recommended on any network shared with other traffic. Use strict priority queueing, with DSCP CS7 (56) for time-critical PTP events at high priority and EF (46) for audio and PTPv2 at medium priority.
• Links and cabling. Overloaded links, or a 100Mb switch or switch-to-switch (backbone) link where Gigabit is required, destabilise the clock. The adapters' own 100Mbps connection to their switch port is normal. Faulty cables show up as dropped samples or cracks in the audio.

What does a clock error in Dante Controller mean?

It means a device is not synchronised to the network's leader clock, and a device that loses sync is muted until it regains it. In the Clock Status tab, a green Sync light means the device is synced to (or is driving) the network clock, and a red light means it is not. A red mute icon means the device is muted, usually for that reason. The Clock Status Monitor icon at the bottom right of the main window turns red when a device loses or regains sync. It turns amber when active monitoring, which is off by default, detects an unstable clock.

• Common causes. The usual causes are Energy Efficient Ethernet on a switch, a 100Mb switch or backbone link where Gigabit is required, incorrectly configured switches, and a problematic external word clock acting as leader. Sync also fails over encrypted VPN links and through intermediate firewalls.
• Subnets. Without Dante Domain Manager, keep the Dante devices on one subnet. DDM uses boundary clocks to carry the clock between subnets.
• Preferred Leader. Ticking Preferred Leader in the Clock Status tab makes that device the leader clock. Tick it on one device per clock domain only — if several are ticked, the one with the lowest MAC address wins.
• Clock history. The History tab of the Clock Status Monitor shows a frequency-offset histogram for a device. A widely spread histogram means an unstable clock, typically from overloaded links or poorly implemented EEE.

AES67

Why won't an AES67 device exchange audio with a Dante device?

Check that AES67 mode is enabled on the Dante device, that its multicast address prefix matches the AES67 flow, and that both ends share a PTPv2 clock. Dante devices in AES67 mode send and receive AES67 multicast flows to and from non-Dante AES67 devices; between two Dante devices, native Dante is used even when AES67 is enabled on both.

• Enable AES67. AES67 mode must be switched on for each Dante device that exchanges audio with AES67 equipment; the AUD-DTE-LINEIN ships with it disabled. In Dante Controller, open the device's Device View and switch AES67 on. Depending on the Dante Controller version and the device, set the RTP mode to AES67 on the RTP Config tab, set AES67 Mode to Enabled on the AES67 Config tab, or use the AES67 setting under Device Config. Where a Clock Config tab is shown, it holds the matching PTPv2 settings. The change can need a reboot to take effect. The AUD-DTE-LINEIN restarts by itself; if another device has not restarted, reboot it from Device View > Device Config > Reset Device. Re-subscribe once it reappears.
• Multicast prefix. When a Dante receiver subscribes to a non-Dante flow, its RTP multicast address prefix must match the flow's address. If it does not, the subscription appears to succeed but no audio flows.
• Clock. AES67 uses PTPv2 on domain 0. A Dante device with RTP enabled runs PTPv2 alongside Dante's default PTPv1. Dante marks PTPv1 event messages DSCP CS7 and PTPv2 packets EF by default; on devices whose Clock Config tab offers a PTPv2 DSCP setting, CS7 can be selected and has the higher priority. Check that nothing between the devices blocks PTP traffic or gives it low priority.
• IGMP. Use IGMP snooping with one IGMP querier active per VLAN (Dante implements IGMP v2 or v3; keep query intervals short and timeouts long). A snooping switch forwards multicast only to ports that have joined the group, so if multicast flows fail while unicast subscriptions work, check snooping and the querier on every switch in the path.
• Model support. AES67 is supported on the AUD-DTE-ECODE, DCODE, LINEIN, XLRIN, XLROUT, USB, USBC and HDMI. For the AUD-DTE-LINEOUT, BT and 2CHAMP, confirm AES67 support with KanexPro support before designing around it.

Diagnostic checklist

• LINK LED on for every adapter that has one; PoE 802.3af Class 0 or backup power present
• Dante Controller computer on the devices' subnet and using the right network interface
• Subscriptions show a green tick, with no warning or error icons
• Transmitter and receiver on the same sample rate
• No red Sync lights or mute icons in the Clock Status tab
• No amber or red bars in the Latency tab
• EEE disabled on Dante switch ports; QoS configured with strict priority, CS7 above EF
• Gain, sensitivity and volume set for the connected equipment
• AUD-DTE-2CHAMP: SPEAKER switch and output terminal match the load, no voltage on TRG, PROTECT LED off
• AES67: AES67 mode enabled, multicast prefix matched, IGMP snooping with one querier active per VLAN

Before you call

Contact KanexPro support at support@kanexpro.com or (888) 975-1368, Monday to Friday, 6:00am–5:00pm Pacific. Have ready the model numbers, the Dante information from Device View > Status tab, the switch make and model, and a sketch of the network topology.

Related resources

• Dante Domain Manager (DDM): Enterprise Setup Guide
• Product Guide: AUD-DTE-2CHAMP