Joe Kendall’s first axiom states: Once you know where the electrons go, you can’t work on the floor no more.
In many ways, Joe was right, as usual. We all know a few audio folk who are a foot smarter than average, and there are some jobs that require a deeper understanding of “where the electrons go.” It seems logical that those with specialized knowledge and abilities should gravitate to positions that match their skill set. I will readily admit that rocket surgery is not in my A2 oeuvre. That we depend on them is common knowledge. The best of them not only know, they teach. And teach. And teach. I know that many times it is easier for them to just do the task. Maybe they are hopeful that we will remember the lessons and sometimes we do. But when repetition is infrequent and technology and gear changes, for me, and possibly others, retaining the lessons is sometimes difficult. I am, and have always been, grateful to those engineers who point us in the right direction and help us understand the troubleshooting process, especially with new technology. The first in my television experience was Craig Debban at KTLA. He was knowledgeable and patient. Craig taught me how to patch an audio control room and why the Ward Beck consoles did not supply phantom power. Still a bit of a mystery. He also talked about troubleshooting. Power supply first. I am grateful for his guidance.
Recently, while I served a 16-day sentence working on two music award shows back-to-back at the MGM Grand Garden Arena in Las Vegas, I asked somewhere around one hundred sixteen and a half questions of two indispensable resources. Truck audio engineer Hugh Healy, Audio Engineer in Charge for Denali/NEP, and FOH Mixer/System Tech Jeff Peterson, Project Manager/Designer, ATK Audiotek, something about Clair. They are the answer men, the brain trust, the Dynamic Dante Duo, the Sultans of Circuits, the Potentates of AoIP. I asked each of them to make a list of work items that the A2’s should know more about, learn, and remember. I appreciate their participation, and I hope they will forgive my egregious editing for the West Coast feed.
We are all experiencing changes, and the resulting complications, in the systems that have become more common in our setups. As they often require extra knowledge and effort, productions have been responsive by cutting prep time, sometimes by a day, and shortening ESU. Recently, on a rehearsal day, we were given a 10-minute ESU to start work with a host on stage. We depend a lot on the plug-and-play aspect of the new devices, but when we have questions, it almost always ends up at the Hugh and Jeff level. Oh, by the way, we want to change blah, blah, blah. That won’t take long, will it? If, as A2’s, we can help, just by learning to troubleshoot some things from the stage, it might save them a bit of time that they really need to use elsewhere.
Let’s look at this as a practical situation, not theoretical. We’ve arrived at the Unlimited Funds Corporation Arena to work on the Pat Ourselves on the Back Awards. Margo greets us and gives us our credentials complete with an advertising logo lanyard. Although there are often differences, we look for similarities in our show setups. Split World is the hub of stage audio. Analog signals from RF’s, bands, audience mics, and other sources are patched into and dispersed from the splitters to the production truck, the music truck(s), and the FOH and monitor positions. Whether a large setup like The Grammys or a smaller show like the Pat Ourselves on the Back Awards, the splitter outputs feed devices that turn the signals into a digital language sent via fiber to each destination’s console.
At this moment, DiGiCo is the console of choice for FOH and monitors. Each DiGiCo console and SD rack is connected to a bidirectional fiber loop. A large show might have five or six desks, and eight or more SD stage racks. Every console and rack must be part of that fiber loop, and each is assigned an ID number by the system tech. A2’s connect inputs usually with a W-4 from the splitter and occasionally access outputs for emergency backups from the FOH console to the production truck. We commonly use MADI outputs from an SD rack to feed RF mic audio to Pro Tools operators for tuning purposes. The SD rack LCD menu needs to be set up to feed the MADI BNC ports with the proper signal. To use the MADI ports as general MADI splits of the rack, change the MADI mode on the output from SDrk (SD Rack) to either 56ch or 64ch.
The MADI ports are referred to as main, aux, split main, and split aux. In the menu, you can configure the split main (SM) or split aux (SX) to be Standard MADI splits of the rack. If the rack is running at 96k because the fiber loop is at 96k, you can set the SM or SX ports to run at 1/2 sample rate, giving you all fifty-six channels on one MADI split port. If the cable run is more than 50’ between the rack and the Pro Tools system, put a media converter on the SD rack end and run fiber to the Pro Tools location, then put another media converter on to finish the run.
—Electrical MADI is very sensitive to ground potential differences.
—Coax MADI has a low output level.
—The receiver circuit does not deal well with noise, ground potential issues, and long cable runs.
Using single-mode fiber allows us to go longer than the 300m limit that is typical of multi-mode fiber and allows us to use the same fiber that’s used in SDI video distribution instead of always running audio-specific fiber. Thanks, Bill and Kit.
There are a lot of coax-to-fiber converters on the market made by different manufacturers, The number that can pass MADI is small because most of them have video reclocking circuitry. MADI will not successfully pass if the circuit is attempting to reclock the MADI signal according to SDI bit rates. Of course, Hugh built his own (for everyone’s use). They only pass MADI, have multiple channels and multiple outputs per channel, and redundant power supplies. They’re also built tough.
The connection from Split World to the production truck is almost always either a Calrec Hydra Box or a Studer Box. Here on the Pat Ourselves on the Back Awards, we are fortunate to have a Denali truck with Hydras. When Hercules was an A2, setting up the Hydra was the second of his Twelve Labors. For the record, putting out Audience Mics was tenth … maybe eleventh. Here on the Denali truck, we usually see two types of Hydras: Fixed Format and Modular. Let’s look at a Fixed Format forty-eight inputs X sixteen outputs. Other configurations are available, but for us, connectivity and the LED status lights are consistent.
Connect the Hydra with a SMPTE jumper (if you are using the Denali box that takes in two Denali Tac 12’s with Delphi connectors and breaks them out to six SMPTE cables (don’t forget to bring the jumpers) and 12 ST connectors on the front of the box. If you are connecting to the Hydra with ST’s from a Tac-12, make sure the Hydra is patched that way.
Once you have AC power and fiber connected, look at the front of the Hydra. A series of LED’s will help you find out the status of your connection.
If your Hydra(s) are lit, like the example, check with the mixer or audio maintenance person to see if the Hydra is making the proper connection to the desk. If the lights are not like the picture, clean the fiber, swap the two fibers, check the lights after each change. If you still do not have satisfactory LED’s, squirt some light from the truck and check the fiber cable at the Hydra. The Status LED information from Calrec gives a more detailed description of the function and explanation of the display. Once you have taken the troubleshooting steps and can describe the current status of the LED’s, ask for help.
A few more things to think about.
Clocking. Albert Einstein once quipped, “The only reason for time is so that everything doesn’t happen at once.” A lesser known aphorism from his days as an A2 states, “The only reason for clocking is so that everything will happen at once.” Clocking is the process of locking all video, audio, and production equipment to a single, ultra-precise master reference signal. For A2’s, it is important to be aware that guest tuning and playback systems may not be set up to follow our master clock. Ticking, clicking, or popping is an indication that the clocking should be checked.
SMPTE Timecode. Now that we have every frame clocking together, we need a way to identify each one. Timecode! Eight digits: hours, minutes, seconds, frames. It can display Time of Day, or in a music show, a separate hour start code assigned for each performance. Timecode triggers video, lights, special FX, and other things. On a recent show, I had six devices at FOH that each needed timecode. Three lighting boards, special FX, video, and “Lasers.” For long cable runs, often we use a Distripalyser, a very handy tool that identifies the format, the drop frame status, the frame rate, and displays the code in real time. It reshapes the code before sending it out and can identify issues such as repeated frames and drop-outs which triggers it to play Disney’s “It’s a Small World” over and over until the problem is resolved. The first line of troubleshooting is to listen for the timecode. Second, make sure that the devices are looking for the timecode format you are providing. Level matters, signal cleanliness matters, hum matters.
Hugh on Dante: It’s not the best system for AoIP, none of them are. To paraphrase Winston Churchill: “Dante is the worst network audio protocol there is—except for all the others.” There are plenty of ways to attain a helpful skill level in the Dante and networking world. With some time and education, we may disprove Joe’s Axiom. Imagine if we could help troubleshoot by knowing the meaning of LED lights and accurately describing an issue. And then go mic a challenging gown on the Oscars and a band on the Grammys.
Well, the Pat Ourselves on the Back Awards is finished, the confetti are everywhere, and as Guy Jones often says, “The show is on its way to Pluto.” The only thing left is to give my profound thanks to Jeff and Hugh for co-writing this column. Your expertise is always very much appreciated.
I read somewhere that there are two stages in an A2’s life. ‘Youth’ and ‘You look great.’ Being just shy of five decades in, I am grateful to still be on the call sheet.