Tutorial: Live-Switched Production with the 罗兰VR-50HD Multi-Format AV Mixer

The first thing you'll notice on a system like the 罗兰VR-50HD is that it's more than just a standard video switcher. It has an audio component on the left that takes up half the panel. There's a good reason for that: Audio is really important. On the right side of the panel, you'll find the video controls, as well as a multiview touchscreen video switcher (图1, below).

图1. The 罗兰VR-50HD. Click the image to see it at full size.

Another key component that separates the VR-50HD from a traditional video switcher is that it is a streaming appliance. The USB output on the VR-50HD is a USB Class streaming appliance, and you can stream using just the USB to a connected computer, which saves you from having to use intermediate webcast encoding hardware.

The VR-50HD is truly an "all-in-one" mixer, just as Roland's description of the product implies. You don't have to have a lot of other pieces of equipment to pull off a successful live-switched production and stream. For example, Roland does make a really nice scan converter, the VC1-SC (下面的图2). 它有VGA, HDMI, and HD-SDI inputs, and it converts these signals to anything you need on the output side. But you don't need a scan converter with this video switcher because it has all those inputs.

图2. The Roland VC-1-SC Video Converter.

罗兰VR-50HD Audio

You also don't need to bring your audio mixing board to a shoot you do with the VR-50HD, because it has a full audio mixer built-in. Let's take a closer look at it.

First off, on the left side of the VR-50HD panel, you have the audio console (图1). It's organized in terms of inputs. The controls for Inputs 1-4 correspond to the mic-level inputs, which are the XLR/TRS (tip ring sleeve) combo inputs you see on the right in 图3(下面). You also have a combination of RCA inputs and tip ring sleeve inputs that are line level--5/6, 7/8, 9/10, 11/12, shown just to the left of the mic-level inputs in 图3(下面).

图3. Audio inputs on the VR-50HD. Click the image to see it at full size.

In addition to those inputs, you can also accept audio inputs from the HDMI or HD-SDI. It's similar to how it works on the video side: You've got a lot of different options coming in, and you can route those inputs where you want them to go. Sometimes I like to use the audio off a camera--maybe it's for ambient purposes--and I can actually get that into the VR-50HD using the HD-SDI or the HDMI feed. Other times I'm working with an external audio company and all I need is a single input off their soundboard. Other times I'm running microphones like the ones I use in the video tutorial above--a lavaliere that I'm wearing and a handheld mic as well.

For this project, Input 1 is already set up, that's the lavaliere microphone I'm wearing in the tutorial video. Input 2 is the handheld mic. The first thing you need to do when setting up a microphone is to adjust the gain. Leaving the slider at about parity, as 所示 图4 (below), I'll turn up the gain for that input, and the audio level will increase, and the lights in the tree on the upper-right side of the audio console will light up at appropriate levels. 最后, there's the main output, the red slider 所示 the lower right of the audio console in 图4. So that's essentially how you set up a microphone input with the VR-50HD.

图4. Adjusting gain for Input 2. Click the image to see it at full size.

Now that we've explored the sliders and additional controls on the audio console, let's delve into the audio setup menu, 所示 图5 (below). In the setup menu, we can use the touchscreen to affect the audio levels. We can adjust the overall audio and gain. We can also solo inputs. In audio testing, it's really important to have solo ability, so I hit the solo button, and can hear just one microphone with all the rest turned off. It's a great troubleshooting technique. I can also mute the output using the button in the lower-left corner of the touchscreen. 

图5. Adjusting audio in the audio setup menu.

Other controls include AUX Send button. In addition to the master line output, we also have an auxiliary audio output. That's really convenient when you're doing two audio mixes. You can use the AUX Send button when you're sending one mix to an archive recording or the live house mix, and the other to the streaming output.

Deeper into the menu, you've got a lot of different features, such as delay. Sometimes audio and video don't arrive at the same time, especially if they're going through different systems. The speed of light is a lot faster than the speed of sound. Sometimes you need to add in some delay for the audio.

There's a 3-band equalizer in the setup menu so you can adjust the highs, the mids, and the lows. Two features in the menu that really offer a lot of added value are the gate and the compressor. With the gate, you start by establishing a noise floor level, and anything below that gets cut off. It's great for eliminating air-conditioner hum, and other types of room noise that you don't want entering your recording.

The compressor works at the other end of the audio spectrum. It helps take those audio levels that would otherwise clip and brings them down and compresses them. So the gate and the compressor really help stretch your audio range.

The third control that you'll find essential is the USB audio control, which is found at the top of the system (下面的图6). This is the knob you can turn to adjust the USB audio level independent of your master and your AUX audio outputs. You'd use this for your USB recording or your USB streaming. 

图6. The USB audio output control.

It's important to have separate controls over all your different audio levels because at different times, some of them might have different audio-level requirements.

Roland has a very strong legacy of audio equipment, and you can see some of the nice touches that they've added into video mixer. Another example is the headphone jack outputs. They've got both the mini for headphones, 1/4", in case you've got the professional standard or in case you have an adapter.