My single chain hookup strategy is a technique that legal videographers can use to configure their equipment. Implemented properly, it provides several key benefits over commonly used wiring techniques.
Some videographers come close to the single chain approach, but I've yet to meet another shooter whose ENTIRE system follows the single chain approach, as mine does. Close is good, but any deviations leave the door open to unreliability in your system. Strategies that don't follow the philosophy of the single chain strategy are subject to serious problems creeping in that the videographer cannot detect until someone else points it out to him -- possibly after giving out bad products to clients and stenographers for weeks or even months.
Videographers sometimes monitor the audio in headphones that are plugged into the mixer's headphone output, while the camera and backup recording device operate on a completely separate audio feed from the mixer. Another popular bad technique is to monitor audio off the camera's headphone output, all the while assuming the good audio you hear in the headphones is making it problem-free to the devices down the line behind the camera, such as the backup deck. These are especially bad arrangements, because the videographer isn't actually monitoring the audio that's being recorded on at least one device. In the case of monitoring on the mixer's headphone output, they aren't listening to the audio being recorded on EITHER deck. Yipes! Sure, they might be able to see the audio levels on the LCD screen of their camera, if they have the VU meter turned on, but without actually LISTENING to that audio, there's no way to tell if it's scratchy, intermittent, distorted, or loaded with a 60hz hum. Can you really tell the difference between VU meter behavior when the audio is cutting out 50% of the time, compare to normal audio? Probably not. This leads to the common problem of making master tapes with bad or missing audio!
Below, in Figure 1, is an example of a bad hookup. Notice that there are two devices that are recording unmonitored audio -- the backup recorder deck, and the audio cassette deck. Even if all goes well, you're already delivering an unmonitored audio recording to the stenographer, but supposing the master tape gets wrapped around the capstan roller and chewed up, you're stuck delivering an unmonitored recording to the client too! This is just one of many possible hookup strategies that leave the door open to catastrophic problems. The important takeaway point is that there are arrows flying every which way -- far from a unified chain of devices.
The rationale behind the single chain strategy is that you form a single chain with all the recording devices in your kit. A single chain for audio, and a single chain for video. The audio you listen to in your headphones has gone through EVERY recording device, and the video you monitor on your TV has gone through EVERY recording device that records video. That's all there is to it. Now let's illustrate with some diagrams.
Figures 2 and 3 below are examples of the single chain strategy in a simplified overview format. Figure 2 illustrates how you can accomplish the single chain technique while using your camcorder as the primary recording device. Figure 3 is my personal setup, using the camera only as a video source and recording on two free-standing recorders. (See the benefits of dual HDD recording here.) The choice of equipment isn't critical, provided everything has the necessary input and output capabilities. For example, the camera in figure 2 would require separate audio inputs and outputs. Many cameras feature a single audio in/out jack that cannot function as both at the same time, so figure 3 is actually compatible with a wider range of cameras.
Figure 2: Using camera as primary recorder,
audio fed from mixer
Figure 3: Two external decks for tapeless operation,
camera used for video source only
In the unfortunate event that you do have a piece of equipment fail, the single chain technique makes finding the problem easier too. Since everything is in a serial chain, all you have to do is backtrack along the chain with your headphones or TV to find where the problem occurs. And because you're only using a single output from each device, it's an all-or-nothing test at each step along the chain. In comparison, the bad hookup in figure 1 might be using three different outputs from the mixer, so all three would have to be diagnosed to track down a missing audio issue before eliminating the mixer as the source of the problem.
The single chain strategy is a logical approach to videography equipment hookup which provides a simpler layout that's easier to understand and remember, easier to troubleshoot, and doesn't require a "techie" level of expertise. Yet it gives a higher factor of reliability and an increased confidence about the quality of the product you deliver. §