Communications options for the CL-9

February 26, 2010 at 7:33 pm


Since the Sound Devices CL-9 hit the blogosphere, views and how-to’s have filled the web.  Instead of rehashing what the CL-9 is designed to do, I’ve decided to take a practical approach to using the communications section of the new control surface.

If the boom operators wish to listen to the same mix as the sound mixer, either the remaining 788T headphone output or the CL-9 headphone pass though will work fine. This is the simplest solution for a communications mix, everyone listens to the same information, and talkback is available from the boom op to the mixer.

Since the CL-9 now provides two return channels, we can assume many of you would like to use them as communications returns from one or two boom operators. The CL-9 returns join the mixer’s headphone mix from the 788T, but the return does not actually pass through the 788T. The first lesson of note is actually a function of the 788T. The 788T outputs are line level, but not loud enough to push a headphone. In order to provide a separate mix to a boom op, here is your shopping list…


1. TA3F to XLRM output cable.

2. JK Audio RemoteAmp. This simple headphone amp runs on a 9-volt and will boost the output of the 788T and provides a gain control for the headphone send.

3. Remote Audio Boom Cable System consisting of the following parts…

A. Mixer end fanout mono version.

B. Boom cable extension, available in 50, 75, or 125 feet lengths.

C. Boom box, boom operators push to talk box.

D. Headphones with dynamic talkback mic.

Now let’s go through the connections. First connect the headphone patch cable and USB interface from the 788T to the CL-9. Next select an output for your boom op feed. One seems to be a good number. Connect the TA3F to XLR cable between output one on the 788T and the input on the RemoteAmp. Remember to install a fresh 9-volt battery. Next the 1/4 male from the mixer end fanout cable connects to the output of the RemoteAmp. The talkback XLR goes to Return one on the CL-9, and the boom XLR to an input on the 788T.

At the BoomBox, simply plug the headphones and talkback mic into the right side of the unit and the boom mic feed in the left side XLR.  Now that you’re wired, let’s tell the recorder what to do.  In our example, we want to send the boom op a prefade confidence of their boom mic, as well as the slate mic. Remember we selected our boom op feed as output 1. Press the menu button on the 788T. Scroll to item 47, OUTPUT 1: SOURCE.  Select input 1, your boom mic input.  Now move to menu item 87, COMMS: ROUTING.  First route COMM 1 to your headphones and output 1, next route the slate mic to the boom op (output 1) if so desired.

Note: In this situation, there is no need to create a boom op mix with other inputs, although that is a possibility. Route all of the wanted inputs/tracks to another track and select it as the output source.