How To: Using a Sound Devices MixPre as a USB Interface

by Matt Collera

The MixPre series by Sound Devices are compact, versatile, and easy-to-use mixer-recorders for use in professional and personal settings. With the ultra-low noise Kashmir analog microphone preamps, anyone can record high-quality multitrack audio for their podcast, instrument tracking, or field recording session. But did you know MixPres can also be used as a USB interface for your computer?

A USB interface allows you to connect inputs (including XLR microphones or ¼” instrument jacks) to your computer as inputs for use in programs such as AVID Pro Tools, Adobe Audition, Zoom, OBS Studio, etc. In this blog, we’ll show you how to set up a MixPre-10T on a PC to listen to your computer sound through the device. Then, we’ll explain how to connect a microphone and use it in Open Broadcaster Software (OBS) Studio.

Out of the box, the Sound Devices MixPre series is USB 2.0 class-compliant, or plug-and-play, and will be recognized by Windows as a two-input (Channels 1 and 2), two-output (Left and Right) audio device, or 2×2. If you want to take full advantage of all 8 microphone preamps, download and install the latest ASIO driver at http://www.sounddevices.com/download/.

Connecting the MixPre-10T to a Windows PC

After powering up the device using your source of choice, (we recommend the XL-WPH3 from Sound Devices), connect the MixPre to your computer with a USB-C to USB-A cable.

After booting up, Windows should automatically set up the MixPre-10T as a 2×2 interface. Check your Sound settings in the Control Panel (Start > Control Panel > Hardware and Sound) and confirm that the MixPre-10T is selected as both the default playback and recording device. If it’s not, select the MixPre-10T then click the ‘Set Default’ button towards the bottom of the window:

Now we need to make sure the sample rate and bit depth set by the MixPre-10T match what Windows is expecting. In the Playback tab, double-click the MixPre-10T. Next, click the ‘Advanced’ tab. Select ’24 bit, 44100 Hz (Studio Quality)’. Click ‘OK’ to confirm. If these values do not match, your computer’s sound will not playback correctly.

Monitoring Computer Audio through a MixPre-10T

Now that the PC is correctly recognizing the MixPre-10T, it’s time to route the two channels of Windows system audio (Left and Right output) through the MixPre-10T to your speaker and headphones.

First, select which channel you would like the Left channel of computer audio (USB 1) to be patched. We recommend choosing Channels 1, 3, 5, or 7 as the Right channel (USB 2) be patched to the adjacent channel, e.g. 1-Left, 2-Right; 5-Left, 6-Right; etc. Set the input of this channel to USB 1.

Once you establish an input channel for the Left channel, activate 2-channel stereo linking on the second page of settings within that channel.

Because of channel linking, USB 2 will automatically be set as the input for the linked channel and its fader will be reassigned to control the panning of this stereo output.

Both channels of your computer’s audio are now routed to the MixPre-10T which can be outputted through a speaker and headphones. 

Connecting a Microphone to Open Broadcaster Software (OBS) Studio

Open Broadcaster Software (OBS) is a popular open source video recording and live streaming program for both Windows and Mac. With a USB interface, not only can you use an XLR microphone to stream studio quality audio on services like Twitch and Facebook, you can also stream and mix multiple audio sources, e.g. a panel of six participants, a three piece band, etc.

In OBS Studio, navigate to the Audio settings (File > Settings > Audio). Select ‘Speakers (MixPre-10T)’ in the Desktop Audio drop-down, and ‘Digital Audio Interface (MixPre-10T)’ for Mic/Auxiliary Audio. Since you confirmed both of these as the default device in a previous step, you can also simply select ‘Default Device’ for both of these options.

Also, while you’re on this page double-check that the Sample Rate that OBS is referencing is 44.1 kHz. Accept these changes by clicking OK.

Unless you are streaming a stereo microphone that feeds two channels into the MixPre-10T, your microphone audio is defaulted to a hard-left pan. To set up a single microphone input as a mono channel, navigate to the Advanced Audio Properties by right-clicking the Audio Mixer. Then, check the Mono box in the Mic/Aux row.

Test to see that OBS is recognizing your desktop audio and microphone by checking the metering bars in the Audio Mixer. If applicable, activate phantom power on your microphone input channel via the MixPre-10T.

Congrats! Your Windows PC is now set up to stream your microphone and desktop audio using OBS Studio.

For questions regarding similar USB interfaces such as the Sound Devices USBPre 2 in our rental stock, contact the Rental Team at rentals@tcfurlong.com. For questions about designing an audio streaming solution for your next project, contact the Sales Team at sales@tcfurlong.com.

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Tiny Comm Tester

TINY COMM TESTER: For Clear-Com compatible intercom systems.

by Scott Helmke

Similar to the Tiny Phantom Power Tester, this is another very simple idea that’s an important part of my toolbox. This allows very quick testing of an analog, Clear-Com style intercom line to make sure it’s receiving power, signal, and can help find stations and belt packs that are causing problems for the whole intercom circuit.  I was actually hoping to design a slightly more complicated tester that would do a few different things, but ran into serious feature creep compared to the utility of this little wonder.

How to build

The theory is pretty simple.  Clear-Com analog party-line intercom puts the 30 volts DC power for all the belt packs and remote stations between pins 1 and 2 of an XLR connector, and the audio signal between pins 1 and 3. The “Call” function works by adding 12 volts DC to the audio signal. 

So this tester simple uses a green LED to show the presence of the power, and a red LED to show the presence of the call light voltage.  Resistors have been added to each LED to limit the amount of current and keep the LED from burning out. 

Construction is fairly easy – you just need an XLR connector, usually the sockets (“female”) end, one green and one red LED, and two resistors.  I built mine with a 2.2k ohm resistor for the green LED (power), and 1k ohm resistor for the red LED (audio and call light).  The resistor values don’t have to be exactly what I used, either.

Make sure that you connect the red LED between Pin 3 and Pin 1, and the green LED between Pin 2 and Pin 1.  To finish, I added heat shrink over all the components.

How to use

Using the tester is fairly simple, just plug it into an intercom circuit to see if power is present – that’s the green LED lighting up.  If you press the Call button on a belt pack the red LED should light up.  If both of those tests work then the intercom should be working. 

Sometimes a belt pack or remote station will go bad, causing all the call lights on the line to light up and kill the audio signal.  I’ve used these testers to quickly find the bad unit, by disconnecting belt packs and stations until the red LED goes dark.  Very useful if you’re by yourself checking remote intercom drops in spot booths.

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Demystify Audio: Wireless Intercom Systems

This is a continuation of our intercom systems blog series. To learn more about analog party-line intercom systems, click here Demystify Audio: Party-Line Intercom Systems.

Wireless intercoms have long been a staple of production intercom systems. In the simplest form, wireless communications can be handled by basic two-way radios, but in the modern era of digital communications, more complex systems are available on the market. In this article, we’ll go through the basics of wireless intercom systems and dive into analog and digital systems.

The Anatomy of Wireless Intercom Systems

The modern standard for production intercom systems is the ability to talk and listen simultaneously with many users. This gets technically complex when we move into the wireless domain because compared to a wireless microphone system that only operates in one direction, wireless intercoms have more specific frequency spectrum requirements. These requirements are handled differently in analog and digital systems.

All modern wireless intercom systems can be broken down into two main components: a base station and user stations (in this case, wireless beltpacks). The base station is the brains of the system and contains transmit and receive radios to communicate to the wireless beltpacks. The base station also provides interfacing to external systems such as other wireless base stations, stage announce outputs, and two-wire ClearCom or RTS party-line systems. Besides the wireless connection, the base station’s primary purpose is to provide the routing of signals between wireless users and these external systems. Lastly, the base station itself acts as a user station, facilitating communication to both wired and wireless users.

Wireless beltpacks (sometimes referred to as “drops”) allow users to connect headsets to talk and listen on the system through built-in transmit and receive radios. After being correctly configured, beltpacks transmit and receive audio wirelessly from the base station which routes the audio streams to other wireless beltpacks in the system and/or to other interfaced systems. Similar to analog beltpack stations, wireless drops allow users to talk on designated intercom channels via buttons that can be programmed to be latching or momentary functions.

Analog Wireless Intercom (UHF & VHF Systems)

Analog wireless intercom systems typically operate in UHF and VHF frequency spectrum used by TV station broadcast. As with wireless microphone systems, the norm is to coordinate these frequencies around FCC licensed TV stations in the individual markets.

For these systems, there are several frequencies that must be accounted for. In order for an analog wireless beltpack to be full duplex, that is to receive audio (listen) and transmit audio (talk) at the same time, separate dedicated frequencies must be used. A typical configuration for analog wireless systems is one system transmitter frequency that broadcasts to all beltpacks and one receiver frequency for each individual beltpack in the system.


A figure from the Handbook of Intercom Engineering.

Typically, analog wireless intercom systems use different frequency spectrums for the uplink (transmissions from beltpack to basestation) and downlink (transmissions from basestation to beltpack) portions. For instance, Radio Active Designs uses VHF frequenices (174-216 MHz) for uplink, and UHF frequencies (470-608 MHz) for downlink.


Learn more about the RAD UV1G System in our rental stock

Analog systems have been an industry standard for many years. One of their advantages is the simple, contained setup and deployment for a single area. Expanding systems to cover multiple areas can require significant additional hardware. Additionally, coordinating frequencies in the limited remaining TV spectrum can be difficult after the sale of the 600 MHz spectrum and ensuing repack.

Digital Wireless Intercom

Digital wireless intercom systems feature “Spread Spectrum” technology, which allows the transmitters and receivers to frequency hop within a certain frequency band. These systems work in dedicated “white spaces” in the wireless spectrum like 900 MHz, 1.9 GHz, and 2.4 GHz.

As opposed to the dedicated receive and transmit antennas of analog systems, most systems deploy cellular communication with many transceiver antennas networked together to the basestation. Most systems use standard CAT5 cable for antenna distribution, allowing for easier deployment of complex antenna systems through different spaces or zones.

With cellular-style digital wireless systems, like Clear-Com Freespeak II or Pliant Technologies CrewCom, coverage and capacity are important for antenna distribution designs. For instance, a single Clear-Com Freespeak II 1.9 GHz transceiver antenna can connect to 5 beltpacks at a time, but a Freespeak II basestation can connect up to 10 antennas and 25 simultaneous users. An example design would be to deploy 5 transceiver antennas for 15 users, and the beltpacks would seamlessly bounce from antenna to antenna based on the open slots and best connection available with no interruption to the audio feed.


Learn more about the Clear-Com Freespeak II System in our Rental Stock

Digital wireless systems can typically support more beltpack users on a single basestation and provide more flexibility and complexity than traditional analog wireless systems. On the flip side, they also involve a fair amount of programming and configuration to be properly deployed. The main draw to using digital wireless intercom systems in frequencies outside of the TV spectrum, allowing more usable RF spectrum for productions operating a large number of wireless microphone, in-ear monitoring, and IFB systems.

Conclusion

While there is no one-size-fits all solution for Wireless Intercom systems, and much depends on your application, it is an invaluable tool of the live production tool kit.

For questions about designing a wireless intercom systems or a quote on two-wire system components, contact the Sales Team at sales@tcfurlong.com. For questions regarding intercom items in our rental stock, contact the Rental Team at rentals@tcfurlong.com.

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Worship Services Moving to the Great Outdoors

Worship services moving to the great outdoors?

Social distancing recommendations, phased reopening plans, and the advent of nicer weather are all factors leading houses of worship to actively consider moving their services outdoors. Interest ranges from curiosity to uncertainly about how get started to full-fledged plans.

TC Furlong has been supporting outdoor services (and outdoor events in general) for much of its 47 year history. We are here now to support your planning as your organization weighs the costs, challenges, and options to move outdoors. Whether you envision a short-term rental system, a purchase, or just need some additional equipment to move your existing assets outdoors, we have the resources to assist you in getting exactly what you need.

On the rental side, TC Furlong has created a variety of affordable, portable, scalable, great sounding, and easy-to-use sound system packages that can meet the technical demands of any service and any size congregation. We can supply everything you need from the mics to the loudspeakers and everything in between including weather protection and storage solutions between services. Our packages are based on building blocks of loudspeaker coverage areas and can be supplemented with any accessory equipment you need including wireless mic systems, worship band support, or any other audio/video equipment and services your team requires.

In addition to the hardware–we are standing by to assist your team with support services including consultation, design, site surveys, staff training, delivery, and our famous 24×7 support that provides peace of mind to your team when you need it most. Package and accessory pricing is flexible and formulated to fit most any budget and provides deep discounts for multi-week use.

If you are considering moving your services to the great outdoors but need help in the planning and execution, contact a Project Manager at TC Furlong today at projects@tcfurlong.com or 888-823-8756.

Yamaha Launches RIVAGE PM5 and RIVAGE PM3 Digital Mixing Systems

Yamaha Launches RIVAGE PM5 and RIVAGE PM3 Digital Mixing Systems 

Yamaha recently announced the significant expansion of the RIVAGE PM Series digital mixing console family with the addition of the PM5 and PM3 control surfaces, and the DSP-RX and DSP-RX-EX DSP engines.

RIVAGE PM5
The PM5 is the latest in the evolution of the RIVAGE PM Series control surfaces.  In a similar layout to the RIVAGE predecessors, the PM5 features 3 Centralogic style bays, but now with a total of 3 large, capacitive touchscreens to allow for multi-finger gestures.  Yamaha has reduced the number of knobs in the third bay to reduce the overall footprint and make room for the integrated third screen. Additionally, meters that were previously above each channel’s ON button have been moved to be along the length of the fader for higher visibility and granularity.  Channel scribble strips have been removed – replaced with naming along the lower sections of the screen – bringing the touchscreens closer to the user for a more efficient reach across the entire console.

RIVAGE PM3
The PM3 scales things down with a 45-inch-wide surface (only slightly wider than a CL5 digital mixer) but retains the 38 faders – three bays of 12, with two masters – found on the PM10, PM7, and PM5.  Featuring a single, multi-gesture touch-panel display and condensed selected channel section, the PM3 is ideal for users needing a compact surface that packs the full punch of the RIVAGE series. Although slimmer in size, the console is compatible with both new DSP engines and does not compromise in I/O capabilities, including up to 288 input channels when paired with the DSP-RX-EX.

DSP-RX and DSP-RX-EX
The new brains of the RIVAGE series are an evolution of the modular DSP engine design and are available in two options.  The DSP-RX unit provides 120 inputs, 48 mix buses, and 24 matrices.  The DSP-RX-EX provides 288 inputs, 72 mix buses, and 36 matrices.  Both DSP engines are built on the same platform, so if you purchase a DSP-RX and need additional horsepower down the line, a DEK-DSP-RX expansion kit can be added to upgrade the DSP-RX to full DSP-RX-EX specifications.

Expansion of the Yamaha Ecosystem
All RIVAGE PM systems use the same I/O racks, the same firmware, and the same DSP engines (with the exception of the PM7 that has an internal DSP unit).  All surfaces feature the same basic fader configuration, and any console file would be compatible across the full line.  Like their predecessors, the PM5 and PM3 are directly compatible with TWINLANe and Dante networks using the necessary HY I/O cards.   A choice of two DSP engines with different mixing capacities, plus a total of five control surfaces including the two new models, gives engineers ample flexibility to create systems ideally tailored to a wide range of applications.

  PM5/PM3

DSP-RX-EX

 PM5/PM3

DSP-RX

 CL5 CL3 CL1
Input Mixing Channels 288 120 72 mono + 8 stereo 64 mono + 8 stereo 48 mono + 8 stereo
Mix Buses
 		 72 48 24
Matrices
 		 36 24 8
Stereo Bus
 		 2 2 1
Mono
 		 1 1 1
Cue
 		 2 2 1

 

In the most basic configuration, the newly released PM5 or PM3 has 120 inputs, 48 mix buses, and 24 matrices, and capable of running at 96 kHz.  In comparison, a CL5 has a maximum of 72 mono and 8 stereo inputs, 24 mix buses, and 8 matrices.  The CL and QL series console do have limited DSP capabilities (as well as the limit of running at 48 kHz), but the entire mix engine is built into the console, while the PM5 and PM3 surfaces need the external DSP engine in order to function.  It is also worth noting that an HY144-D card is needed to connect a PM series console to a Dante network, rather than having an integrated Dante port like the CL and QL series.

The PM5 and PM3 surfaces are a highly anticipated bridge between the functionality of the RIVAGE series and the price point of the CL series. For questions about designing a RIVAGE PM system, contact our sales team at 847-367-9588 or sales@tcfurlong.com.

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