This sample was submitted by Craig Maier of Diamond Cut Productions
This recording was made in 1967 of my High Schools Class play, Brigadoon. I was responsible for the light and sound aspects of the project The sound responsibilities included the PA system and also the Recording of the play. The sound system consisted of two mics hanging from risers above the stage and two mics located above the orchestra pit. They all fed into a Mixer which drove a Pre-Amp and then a Power Amplifier for the sound reinforcement system. Another set of outputs fed my Magnecord 1028 1/2 track, 15 ips tape deck. All of the audio equipment was electron tube based including the tape recorder – – – tubes were still the state of the art in audio at that time. All of the tube based equipment except for the Magnecord tape deck was designed and constructed by myself in the two years prior to this particular event. (The speaker system used JBL drivers, but was DIY)
The problem observed here as heard in the “before” was probably the result of a bad shielded cable between one of the mixer outputs and one of the tape deck inputs. It appears that I noticed the problem (one VU meter was probably not dancing correctly) and I started by adjusting one of the channel gain controls on the tape deck. Ultimately, it appears that I started moving cables around until a signal became steady into the tape deck, but as you can see and hear, it took a while to find the problem and fix it at that time.
This “after” example shows how the Diamond Cut Editing capabilities can fix this type of problem.
Wherever there was a drop-out of the signal on the offending channel, I carefully marked them with the Diamond Cut Markers (the “M” key) (zooming in to be sure that they were exactly in the correct place). I highlighted each section and clicked on the good track (R or L on the toolbar). Then I copied that to the clipboard and pasted it to the opposite track without moving the markers. I noticed that there were still some large transients on both tracks which I interpolated out with the “I” key. Sometimes, very tiny transients occurred where I pasted into the bad track which I interpolated out with the “I” key after highlighting the problem.
Then, I was left with wildly varying gain settings on each channel and in some cases, both channels. The goal was to “feather” the gain compensations in so that they would be the inverse of the way in which the tape deck controls had been moved in real time, I used the “curve” setting of the Gain Control feature. By adjusting the curvature using the spline inflection points, I was able to reverse the gain vs. time problems that I had injected onto the recording back in ’67.
To smooth out the changes in stereo image (albeit not perfectly), I applied a slight amount of reverb to the sections of the file that had been copied from one channel to the other, with some overlap past the edit marker boundaries.
Lastly, I gain normalized the system to -2 or -3 dB.