Let AES67/Ravenna and Dante Devices talk…

AES67/Ravenna gains more and more interest – especially for broadcast applications. KLANG:quelle is often used as a reference headphone monitor amplifier and AES67 support is a very important feature in this context. However, it often remains unclear how to use AES67. In the following we will show you how to connect AES67 devices to a KLANG product (e.g. KLANG:quelle). We also explain how to route an AES67 flow from a Dante product (e.g. KLANG:vier or KLANG:fabrik) to a Ravenna/AES67 device.

Tools required for this tutorial…

• AES67 device
• or e.g. Ravenna Virtual Audio Device for Mac (free soundcard driver)
• KLANG device to receive AES67 flows – or other Dante device with AES67 support
• PC for configuration with Dante Controller installed
• Additionally, KLANG device to send out AES67 flows (e.g. KLANG:fabrik, KLANG:vier)
• Please make sure that your network switches are suitable for Dante and AES67.

Step 1: RAVENNA/AES67 Virtual Audio Device

In this example we use the free Ravenna sound card which can be downloaded from Merging. Install the sound card for Mac OS X and follow the instructions.

Open the RAVENNA preferences pane in your Mac System Preferences. In our example we use 8 output channels and 8 input channels at 48kHz.

Please note: Dante products can only operate with 48kHz once AES67 support is enabled.

Click on Advanced Settings… Go to Session sources and click on the LINK symbol (just below the General settings button) to generate a stream. In this example, we use 2 channels, set the Codec to L24 (24 bits) and the Frame size to 48 samples (AES67 default).

Step 2: Connect Network Devices

Power up all network devices including the Dante receiver (for example your KLANG:quelle) and connect them to the same network including the computer running Dante controller.

Step 3: Activate Dante AES67 Support

Open Dante Controller. Double click on KLANG:quelle to activate AES67. Go to the AES67 config tab and adjust the settings as shown in the following screenshot. First of all, activate and click reboot. After the reboot is completed, adjust the IP range. Here, we have set it to 1.

Please note: If you specify the Address Prefix before rebooting the device, the prefix will be overwritten by the default value.

Step 4: Route Audio Streams

In Dante Controller, AES67 devices are indicated in blue. Our Ravenna sound card stream appears on the top as Transmitter. There is no configuration (double click) available inside Dante Controller for AES67 devices. Now route the audio streams to KLANG:quelle as usual for Dante only networks.

Please note: It might be required to initially route channels slowly, i.e. wait for the green check mark to appear before routing the next channel.

Step 5: Create a Dante AES67 flow

Activating AES67 support is not enough to transmit audio to the AES67/Ravenna world. So now, we need to create an AES67 flow. Flows are already known in standard Dante setups. They are multicast streams that can travel to several receivers at once (latency is always 1ms – the standard Dante streams are unicast with variable latencies).

To create your flow, double click on the Dante device in Dante Controller and go the Transmit tab. Then click the 4th icon from the left – a blue dot with a double arrow to the right. You will see the flow windows as shown in the screenshot below. Check the AES67 flow option and add up to 8 channels to the flow. Once you’ve done this, the flow will again appear as a blue transmitter (AES67) in Dante Controller and you can also access this flow through your Ravenna device’s webpage using SAP.

Step 6: Route audio to an AES67 receiver

We have to use the AES67 webpage to route the audio, as the Dante Controller only allows to route audio to Dante products. So, open the according webpage – we use the Ravenna sound card in our example –  and your AES67 flow will now appear on the list.

How to connect Dante devices without AES67 support?

KLANG offers Dante Brooklyn II module firmware/software updates for all products for download here. For other products please look for a new Dante firmware update on the manufacturer’s homepage first.

However, there is a way to route streams to Dante devices that do not offer AES67 support by using KLANG:fabrik’s routing matrix. Route AES67 to KLANG:fabrik. In KLANG:app route the incoming Dante audio channels directly to the Dante output channels. Via Dante controller, you can now use these channels as normal Dante streams.

Clocks

In the example we used the following clock settings. The master clock in Dante is the clock master for AES67 as well.

AES67 always incorporates multicasts (flows). Hence, network switches, routers and other network products have to be multicast proven or otherwise, multicast filters have to be used. KLANG:fabrik and KLANG:vier offer switch configuration incl. multicast filtering.

AES67 flows are not the same as Dante flows. AES67 flows (up to 8 channels per stream) can only be routed to AES67 products – and especially not to Dante products without AES67 support.

The packet time of AES67 connections to or from Dante devices is always 1ms–regardless of the setting in the Dante controller.

The sampling rate for a Dante device using AES67 flows is always fixed at 48kHz and cannot be changed in the Dante controller unless AES67 flows are deleted or the AES67 support is deactivated.

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