Tips & Techniques - July 1990

Teach An Old Dog Some New Tricks - "Get the Most from Old Gear"

by Chuck McKay

There are two immediate side benefits to changes in the quality of consumer audio gear. First, our technical ability to manipulate sound keeps improving. Secondly, the cost of that manipulation keeps getting more affordable. If we all had unlimited budgets for new production toys, this tip wouldn't be necessary.

What do you do when you still can't justify the dollars for the new hardware you'd like? Well, we production rats always have more creativity than dollars, and a creative solution should start with an assessment of the tools available.

Check the back room, the local guitar store, the junk shops downtown. It's amazing what people don't want anymore. Perhaps the third benefit of new technology is the tendency of previous generations of audio processors to become "cast offs."

The MicMix dual-spring reverb was one of the best on the market a decade ago. It's junk today. Five years ago, the hottest production toy was Eventide's original Harmonizer. This week, a used equipment supplier told me that no one would make him an offer on several in his stock -- not even a ridiculous offer.

"Wait a minute," you say. "I need to sound competitive today. So you've found some old effects processors for next to nothing. They still don't sound good by today's standards."

Well, true, but let's look closely at these old sound boxes. In my experience, the factor which limits the performance of most older effect processors is attack/release time constants. Most of us don't possess the ability to re-design electronic devices, so we'll need an unusual technique to cope with their limitations.

Instead of changing the processor, consider changing the audio that we run through it. Playing a recording back at half speed has two major effects on the recorded sound. It lowers all the tones on the tape by an octave, and it makes each sound last twice as long. This increased duration of each sound makes the attack and release of each note appear to double. When run through a processor at half speed, the processor only has to respond one-half as quickly as it would at normal speed. This will effectively double the useable attack and release times of the processor. Confused? Let me show you how this works.

You'll need two dual-speed tape recorders and the processing device you choose to work with. Suppose that you've found an old Gates Sta-Level AGC amp in the engineering department. With the expectation of compressed voice tracks, you've talked the engineers into wiring it into your production studio. You run your microphone through the Sta-Level and discover that it has wretchedly SLOW response times. It sucks up room noise behind your vocal, and worse yet, at any significant level of compression, it distorts your voice.

Here's the procedure: Record your voice "dry" on the first tape recorder. Drop the tape speed of this machine to one-half as you play back your voice track. Now, dub it (through the AGC) to a second recorder, which is also recording at half speed. When you play the second tape back at normal speed, you'll hear an added punch to your voice. Yes, this is time consuming. Yes, it will probably take several attempts to find the best operating points of the AGC. And yes, it will sound "bigger" than your unprocessed voice.

This same technique has multitudes of applications. Are you lucky enough to have access to a Burwin or Dynafex dynamic noise filter? Ever notice that when you're trying to remove hiss from a tape that really needs it, you hear the filter gating on and off? (You'll hear that gating action as bursts of hiss behind the audio.) Drop the tape speed to one-half normal speed and run it through the processor. Again, it may take a few attempts to find the proper threshold settings, but at some point, a majority of the hiss disappears.

Time constants change with speed, but don't forget that frequency response does too. If your console has a three band EQ (10K, 1K, 100Hz), changing the tape speed as you dub can effectively create nine different EQ points. Doubling the tape speed makes the effective frequencies 5K, 500Hz, and 50Hz. Halving the tape speed makes the EQ effect 20K, 2K, and 200Hz. Of course, if you have a vari-speed control on your tape recorder, your EQ points become infinite in number but the EQ range will be limited by the range of the vari-speed.

Use your new EQ frequencies to tighten the bottom end of out-of-house tapes. Double the tape speed, roll off the lows as you dub to another tape, then return the dub to normal speed. You'll find a fat bottom end that rolls off nicely at 50Hz. ♦

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