From the June 1989 issue of Radio And Production

Tips & Techniques

Multi-Track Work: Punch-ins & Spot Erasures

by Jerry Vigil

Punch-ins are real time savers in a production room, especially with voice tracks. Say you're laying the voice track for a 60 second spot, and, after you've recorded the track, you realize you read the phone number incorrectly at the end. With a reel of 2-track work tape, you might simply re-record the last few seconds of the spot and edit it to the first take. With multi-track tape, however, you would be one of the few if you actually cut and splice on a 60 dollar reel of half-inch tape. Rather than re-record the entire track, a punch in will save you lots of time.

A punch in on a multi-track is done by backing the tape up to a point a few seconds prior to the point where you want to begin re-recording the voice track. Put that track in the sync mode with record ready and roll the tape. At the point where you want to begin recording, just hit record and begin reading that part of the script over again. To do this, you should be monitoring the output of the multi-track machine (console in tape monitor mode) and not the program of the console. When you hit record, the multi-track machine will automatically leave the sync mode and go into the input/record mode, so you will be able to hear what you are recording.

The best places to punch in are places where you have a bit of a pause, such as a place where you took a breath. The timing involved with punch ins on a voice track is critical. It will take time to master punch ins on voice tracks, but it's easy once you get the hang of it.
When you have the machine in the sync mode and hit record, the erase and record heads take over. The sync mode is playing back audio from the record head, but the record head is an inch or so away from the erase head, so the erase head and record head are not actually in sync with each other. At 15ips, this will cause a delay of roughly 1/15 of a second. This delay means that the erase head won't begin erasing at the exact point that you punch in. This is enough delay to make a difference on a tight punch in. This may be a little confusing; Just realize that you can punch in a fraction of a second before you think you can, without erasing audio at that point. As with anything else, practice makes perfect.

Now that we've covered punch ins, let's look at how to fix the bad ones. Even the most experience "punch in" artist is going to have a few bad punch ins when working with voice tracks.

Let's say you're recording the line, "Today only, save fifty dollars." What you meant to say is "...save fifty cents." There is no pause between "fifty" and "dollars", so you will have to do your punch in between "only" and "save". So you do your punch in, but you don't hit the record button soon enough. The new track plays back like this: "Today only, sa- save fifty cents." You will discover that the more times you try to do a particular punch in, the messier the track will get. Sometimes you'll wish you could just edit the "sa-" out, but alas, you don't want to cut that 60 dollar reel of 1/2 inch tape up. You can, however, use your grease pencil and make some edit marks!

Determine whether your machine is in the "repro" mode or the "sync" mode. If it's in the "repro" mode, use the playback head to make your edit marks. If it's in the "sync" mode, use the record head. For this example, let's use the playback head. Remove the tape from between the capstan and pinch roller and place it outside the capstan. This will disable the transport of the tape and allow you to enter the "record" mode and freely rock the reels back and forth. Put the voice track in "safe" mode and hit "record" (and "play", if necessary to enter record mode). Now rock the reels back and forth and cue up to the point just after the word "only" and right before the "sa-" sound that you want to erase. Put an edit mark there, dead center on the playback head. Move the tape just past the "sa-" sound and just before the word "save". Place an edit mark there. The space between the two edit marks is the area you want to erase. Your machine is still in the record mode, but the erase head isn't "ON" because the track is in the "safe" mode. Move the tape to the erase head and center the head between the two edit marks. Switch the track to "record ready" mode. The erase head is ON. Carefully move the tape back and forth, keeping the erase head between the two edit marks. Once you've passed the erase head over the tape, from the first edit mark to the second one, the unwanted audio is history, and the punch in is perfect! ◙