Crestron Avia DSP first impressions

Crestron Avia DSP

At Utah State University we typically use audio DSP devices in distance learning capable classrooms. We have experience with a variety of these devices, and have an install base of more than 150 Cisco codec equipped classrooms on our main campus and across the state at satellite campuses and learning centers. Over time, we have deployed devices from a variety of manufacturers – Polycom Vortex, Biamp Nexia, and BSS Soundweb. 

We rely heavily on Crestron control and video switching in our installations, and so were very interested in the new Crestron Avia DSP. We have installed a handful of these DSP’s in rooms on our main campus as part of a recent classroom technology upgrade. One installation provides the audio mixing and routing for a distance learning classroom equipped with a Cisco SX-80, Crestron processor, Crestron video routing and Shure steerable ceiling array microphones.

Hardware

For this installation we used the DSP-1283, a single rack unit box with 12 analog in, 8 analog out, 32 channels of Dante, SIP/POTS telephone I/O, 2 channels of USB I/O, and 8 internal ’Aux’ busses (more on those later), and AEC. The chassis has front panel bargraph meters for the analog inputs and outputs. Our room audio sources are a wireless instructor lavalier, two Shure MXA910 ceiling arrays, and line inputs from room media sources. Outputs feed the Cisco codec microphone input, presentation content line in, PC audio in for lecture capture, and two stereo amplifiers for 4 speaker channels. The Avia devices are fixed architecture DSP’s The processing blocks are preassigned to channel strips and analog outputs, and the processing objects are available on the analog I/O and aux bus inputs only.

Performance according to published specs is good, with 24-bit A to D, 110 db dynamic range, Equivalent input noise of -125db, and an input gain range of 66db which exceeds the available input gain of 48db on the BSS devices and could be helpful in some situations.

Setup

Network setup was simple. In our operation, we run all devices in DHCP, but use our enterprise network management tool to assign static IP addresses where needed, and we assign all Crestron devices to their own VLan. Because this DSP has a Dante interface, it has a second MAC address , and requires a second IP address for the Dante network. The software tool has device discovery, or you can manually input IP addresses for communication across subnets.

Software

For Crestron users who will tie this into a control system, the devices’ Crestron net ID (IPID) is set in Toolbox, but all other configuration is accomplished through the stand-alone application - Crestron Avia Tool which installs in your Toolbox folder if you have installed other Crestron software.

There are a few nagging issues in the user interface, undoubtedly most can be attributed to the fact that this is a new product.

The interface has a single main view, but separate signal and system view tabs.

In System View input and output meters are available, crosspoints can be muted, and levels viewed for each crosspoint by hovering the mouse. A double click will mute a crosspoint, but the crosspoint levels may not be adjusted. This view also shows a list of available devices.

Signal view allows adjustment of crosspoint levels and mutes. A single click brings up a numerical db level display with up/down level adjustment arrows, or a right click brings up a slider with copy, paste, undo and crosspoint mute buttons. Here you can copy your level settings and paste to another crosspoint, but this requires you to open the destination crosspoint with another right click, and select the paste button. Windows shortcut keys (CNTRL C, CNTRL V) do not work, and levels may not be pasted to a range of destinations at once.

Channel names are visible on a toggle, but toggling the name view on in the system view does not make them visible in other views, you must also turn them on in signal view if you want them to remain visible as you change views

Input and output rows  are numbered, but crosspoint columns are not numbered. A small complaint, but you must either count across or hover the mouse to check the output crosspoint number

Open the help file, and the window opens and stays in focus – you must close it again before working on whatever you needed the help for in the first place

Beware of the dual input mutes – analog inputs have an input gain module with its own mute. This is separate from the channel mute, and is visible in the system view, but not the signal view unless you open the channel’s input gain block.

A potentially large issue with the fixed architecture - full DSP blocks are available on only the 12 input channels. This device has 32 channels of Dante available, but it is only matrixed. A Dante input must be assigned to one of the 12 channel strips for full DSP features to be available. It is important to be aware of this as you design your system, this device is limited to 12 input channels and 8 output channels for anything other than simple routing and level control. Other flexible architecture DSP’s we have used do not have this limitation, allowing processing of up to 64 channels of Dante without adding additional boxes. A large system using one of these other devices could be considerably less expensive than the multiple Avia boxes that would be needed for a similar channel count.

Finally, the Aux busses. A bit of an odd feature as implemented. These are not your mother’s aux busses. They do not function as an audio engineer would expect an aux to operate. There are 8 aux sends which seem to be intended to be used as group submasters. Auxes, labeled as Inputs and Outputs are internally bussed, output tied to input, almost like an insert loop or an aux buss brought back to input strip. Signal can be sent from any channel strip or Dante input to an aux bus. The signal then routes automatically to the corresponding aux in. The aux in strips have DSP available and the matrix allows routing with level and mute control to any output, so this does allow a way to expand processing capacity and grouping and processing of input channels.

Crestron interface

Arguably the biggest reason to choose these devices is the integration with other Crestron hardware. Crestron has developed a neat UI export tool which will create touchpanel smart graphics objects automatically, which can then be added to your touchpanel project. These objects can communicate directly to the DSP while adding only minimal support in a Simpl program.*

In Simpl windows, the default control symbols for the Avia DSP’s are fairly complete, but missing crosspoint level or mute controls.

Bottom line

Good integration with Crestron, and very usable in a smaller installation. The advantages in a system exceeding 12 analog inputs or requiring multiple channels of Dante are not as great. Software is a good first implementation, and I eagerly await updates for some needed improvements. Cost on these devices ranges from $2000 to $4000 list, and seems reasonable, especially when the benefits of the Crestron integration features are factored in.


*Updated after more time to test with the box - Simpl integration requires the import of one module to carry CRPC data. On program initialization, communication is established between the touchpanel and the DSP, requiring no further processing in the system program. Also, controls created in the UI export tool are used in the VTPro-e project but do not produce a custom module for use in the Simpl program. Did I mention crosspoint level and mute contol is needed in Simpl?
Hey, I love the meters, though...