Wohler Versatile audio/video proccesiing monitors
This time we have decided to test one of the most versatile audio/video processing monitors on the market. It has been designed by WOHLER, a company with a wide experience on the broadcast market and which is constantly investigating and updating its technical equipment. In short, it’s a reference brand at an international level.
The AMP2 family, with a long career on the market, has had some changes from its origin and some considerable upgrades, the great majority related to updates of new formats and systems.
In this test bench we have the AMP2-16V model, with the following options installed:
- 3G/HD/SD-SDI-V Card
- AES Input Card
- AES Output Card
- Analog I/O and SPDIF TOSLINK Card
- Dolby Card D/E Card
We are going to test its performance and functionalities, as well as the different aspects related to its operation: from its configuration and physical appearance, to the effectiveness of its features.
GETTING TO KNOW AMP2-16V
It’s an in-rack equipment which occupies 2 RU. There are two screens on the front part with a resolution of 800×480 which are used as the virtual interface for the VU-Meters and data presentation. It also includes the knobs and switches to navigate the menus which are pleasant to touch and mechanically correct. Also, two loud-speakers, the potentiometer to control the output volume of the two loud-speakers, the potentiometer to balance L & R channels and a jack output to connect the headphones.
At the back the different modules are installed in slots to enable scalability regarding features, as well as the power source. We miss the ON/OFF switch in the power supply. It should be installed either on the front part or next to the plug.
The most important aspect is the routing capacity from any type of audio input to any audio output (embedded in SDI signal, AES, analogue,…).
Another interesting feature is the possibility of working with Dolby, also, the equipment automatically detects when a Dolby signal is entering. This way it can analyze metadata or monitor, for example, each of the channels individually.
The whole equipment is controlled trough one of the front screens, together with the knobs and navigation switches. Browsing the menus is not very complicated, although sometimes we miss the possibility of a remote control to operate the equipment trough the Ethernet connection and the web application. It would make the menu navigation smoother and faster compared to the use of the knobs and switches. It would also be a good option to have a VGA output to put the data of the screens on monitors with more inches.
It is possible to set up the knob functions to easily and quickly access the different options, such as the preset change. Once all the types of inputs are configured it’s possible to save the configurations on presets and just change the preset to adjust the configurations on different situations.
One aspect we should have in mind is the fact this equipment is capable of measuring the loudness (LKFS), an important feature when working with Dolby channels.
Main features of the equipment
- Simultaneous monitoring of the different formats
It’s possible to set up the equipment to monitor at the same time the different types of inputs. Moreover, we can hear simultaneously trough the built in loud-speakers the different inputs.
- Cluster monitoring selection
The equipment enables the cluster configuration, this means, it can group audio channels to work on them as one entity. For example, a cluster formed by the 4 audio channels belonging to an audio group of the SDI signal can be defined or it can group the Dolby channels. All this can be done through the Monitor Mixer Configuration Menu. The cluster configuration menu is quite intuitive.
Once they have been configured, it’s possible to select which cluster you want to hear trough the built in loud-speakers or analyze the level of loudness by pressing the corresponding knobs. The knob corresponding to the cluster selection also enables you to silence some channels or hear only some of the channels.
- Instant stereo Downmix
The equipment has the capacity of downmixing the Dolby, a very useful function when comparing it with a stereo.
It’s possible to measure the loudness (LKFS) of any cluster. The loudness level can be seen on the lower part of the screen.
- High quality audio system
The sound quality which is provided by the two built in loud-speakers is good, as well as the headphones output in jack.
Routing and internal mixture
One of the characteristics which attracts attention and enables a wide range of possibilities and configurations is the capacity to route any input to any output., as well as the possibility of mixing different channels. This provides a great flexibility and power regarding this matter.
- Audio processing card
In the Audio Processors menu you can set up the different options installed in the slots, like for example decide which inputs should be routed in each of the output slots, set up the delay, etc. All by using the knobs and navigation switches.
- Genlock input
In the Hardware Configuration Menu you can define the source of the clock, enabling the synchronization between the equipment and the genlock input, with any of the inputs of the slots or internally.
- Possibility of delaying the audio monitoring output
If it’s necessary, it’s possible to delay the audio towards the built in loud-speakers thanks to the Configure Monitor Mixer.
- Possibility of delaying the embedded audio in the SDI signal
Another option included in this device is the possibility of delaying the audio channels of the SDI inputs trough the corresponding Audio Processor Card Menu.
Set up of the SDI output
As we have mentioned earlier, you can route any channel to the SDI signal, mix or delay.
- Data presentation screens
All the information and screens of the menu are presented in two front screens. We miss the fact of having the information in a connector to be able to display it in an external monitor.
- Compatibility with different formats of video input
The module 3G/HD/SD-SDI-V Card enables a wide variety of input formats which provide the equipment with a great flexibility.
- Screen configuration
The information presented on the screens can be configured on the Main Screen Configuration Menu. It enables you to choose one option among the predefined options of the equipment in order to set up which option is the best for your needs.
- Dolby zoom
This option enables you to monitor individually each of the Dolby channels, both at a loudness level and at a metadata level. This option of individually managing each Dolby channels also allows you to set up the other output modules (AES, analogue…) to externally monitor each and one of the channels.
- SuperPair Input
You can set up one of the inputs as SuperPair Input. This input will always be heard trough the built in loud-speakers independent from the cluster selection by using the knobs and the potentiometer to adjust the volume in the front part. This is a very useful possibility to integrate, for example, an input from the intercom system because it allows you to hear the orders independently from the operation of the equipment.
- VU-Meters configuration
In the Meter Configuration Menu you can set up the VU-Meters in order to adjust them to your way of work.
- Phase monitoring
It includes a phase indicator. The indicator turns green when the channels are in phase or red when the channels are not in phase.
- Dolby metadata presentation
In case of detecting a Dolby signal, it’s possible to set up one of the screens for the metadata presentation.
ASSESSING ITS POTENTIAL
I normally explain a real test done to the equipment we have on the test bench. In this case, I had such good expectations that I performed also several tough tests apart. Naturally, the first test was the integration on the up/down centre and the signal distribution (Central control) to monitor the external signals and fix the quality parameters we establish. The monitoring by layers allowed us to detect problems on the audio signal at a glance and, at the same time, we were able to analyze it and correct it by sending the correct signal to the destination studio.
On the second case, we install it on a production studio to verify if the Dolby signals we were generating and its mixture with an external contribution. The equipment performance was extremely precise, the screen we used to read metadata gave us all the first hand information we needed for the parameter treatment of the final mix. This, together with the downmix we made to compare it with the stereo values, was of great help because we were able to do it in one equipment. I want to highlight that we normally use three different equipments for this same process.
WHAT IS MISSING
We miss the possibility of operating remotely on the equipment and the fact that the information can’t be presented on an external monitor. Instead, it’s presented on the built in screens of the front part. Lately, with almost all the equipments we have on the market, I miss a general ON/OFF switch because in case of detecting any problem on the current you can switch it off without having to look the multi-socket adaptor on which you had connected the device or removing the back IEC.
It’s a very complete equipment regarding the input configurations because it enables you to route any of them to any of the outputs, generate delays, mix… Another important aspect is the possibility of configuring the input groups with the cluster and the fact of having in one screen the different sources, which can be selected using the knobs to hear one or more inputs trough the built in loud-speakers and measure the loudness.
There is another important fact: the work capacity with the Dolby signals, because they are detected automatically. Moreover, the equipment allows you to independently analyze the channels by measuring its loudness, checking the metadata and routing the channel to other output modules. It’s also possible to set up a downmix in order to compare it with other stereo signals.
It offers a user-friendly data presentation on the screens which enables you to see at a glance the loudness measurements, phase.. . Also, the menu navigation it’s not very complicated.
I want to thank WOHLER for lending me the equipment to do this test bench. Also, I want to thank my colleague Biel Pol for its implication on the development of this test bench, as well as IB3TV for letting us use its facilities.