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Tutorial: Mixing, Switching, and Streaming Live with the Roland VR-3EX All-in-One A/V Mixer

In this tutorial we'll explore the robust audio and video mixing, switching, and live-delivery feature set of Roland's versatile next-generation 4-input VR-3EX, HDMI-capable A/V mixer.

 

An A/V mixer is very different from a standard video mixer in that it has an audio component to it. The Roland VR-3EX is no exception. On the left side, it has a full audio console with many inputs, including XLR inputs, 1/4” inputs, RCA stereo inputs, and mini 3.5mm stereo inputs. The 3.5mm inputs means you can take in an analog computer input and you can also take audio from embedded HDMI signals as well. It’s a very versatile, full-fledged audio mixer.

As for the video side, one issue I want to address right from the beginning is, “Why is the VR-3EX a standard-definition video switcher in the year 2014?” There’s a very good reason for that. There’s still a need for video switchers that operate in standard-definition.

What’s more, the up-res 1080p output on this video switcher is exceptionally high quality. This is, in large part, due to the fact that we’re using HDMI digital inputs, as opposed to analog inputs. Analog composite and VGA inputs are available on this switcher, but if you can avoid using them, please do so because the digital-to-digital conversion is not a conversion per se. There’s scaling involved, going from 480p to 1080p (Figure 1, below), but it provides much higher-quality output than you’d get if you started out with analog video inputs.

Figure 1. 480p SD HDMI signal upconverted to 1080p on Roland VR-3EX. Click the image to see it at 1920x1080.

That, in itself, is one of the main reasons why Roland updated the VR3 with the VR-3EX video switcher: to add HDMI digital video input that wasn’t available on the VR3, making the VR-3EX a full-fledged digital video switcher with a digital-to-digital workflow, while retaining the ability to de-embed the audio from those HDMI video inputs and bring it in from a different audio source.

Audio Features

Let’s delve a bit further into the audio functionality of this A/V mixer. For starters, you can see in Figure 2 (below) that there’s an array of knobs and sliders, just as you’d expect to see in any audio mixer. Roland has a rich legacy of audio mixers, so it should come as no surprise that they’ve done a really good job of laying out the audio controls on this A/V mixer. There are 4 primary sliders that correspond to the XLR/TRS inputs that you’ll find on the side. In the video tutorial I produced to accompany this article, I mic’d myself up using one XLR from my wireless lav, which plugs into the side of the VR-3EX unit. For each of the 4 XLR inputs there’s a gain knob at the top, as well as a 3-band equalizer for highs, mids, and lows. The VR-3EX also features 2 internal microphones, located on the top left and top right of the console.

Figure 2. The Roland VR-3EX has volume sliders for each input and the main, as well as ¼” and 3.5mm headphone outputs. 

The first input I’m going to adjust is the XLR input for my lav microphone. We start off by adjusting the slider by raising it to the parity mark, which is about midway point where there’s no volume gain or attenuation. That leaves me free to adjust the gain. If I adjust the gain too high, I’ll get some clipping that will be visible in the audio monitor.

Using the Audio Setup Menu

The tendency to clip suggests the need to tweak some items in the setup menu (Figure 3, below). To address that, I click the SETUP button under the appropriate audio input. This brings up a menu where I’ll see two adjustments, Gate and Compressor. These are two very useful audio level tools. The Gate enables you to eliminate any hum or other noise in the background by setting a noise floor level. Anything that falls under than noise floor threefold will be attenuated. The Compressor allows you to attenuate audio once it reaches a certain threshold. If I adjust the levels, I can make sure I’m not clipping my audio. Other controls used in tandem with the Gate and Compressor allow you to extend your usable audio range.

Figure 3. The audio channel setup menu adds additional audio features like Gate, Compressor, Audio Delay, High Pass Filter, and Pan.

During the audio setup and testing phase, the Solo and Mute buttons allow me to isolate individual audio inputs so I don’t have to adjust the sliders; I can just toggle between them.

Finally, in the bottom-right corner of the Audio Setup menu is the Delay. Audio doesn’t always arrive at the same time as the video. This may be due to the fact that the speed of light is faster than the speed of sound; or, due to audio processing, some audio signals may arrive a little sooner than others. When I was producing the video tutorial that accompanies this article, the HDMI audio came in with a little delay compared to the XLR audio source plugged directly into the switcher, causing a bit of an echo with both sources in the mix. To compensate for this, I add a slight delay to the XLR audio source to match the delay on the HDMI source. That’s one of the techniques you can use if you experience this type of echo effect. It’s nice that the Roland VR-3EX has that type of audio delay functionality built right into the video switcher.

One really nice audio feature that Roland has added to the VR-3EX is the availability of an AUX send for audio. You’ve got 1/4” and RCA outputs, and for audio monitoring there’s a 3.5mm headphone output as well as the 1/4” output.

On the program monitor, you can see the individual audio levels for each of your inputs and outputs. It’s really useful when you’re trying to get the right audio level mix. You can see what inputs are working and have levels, and which ones don’t.

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