Studio Insider--May, 2012
 
Studio Insider #170 May, 2012

More about maximizing audio levels with acoustic instruments (making it really LOUD)

Quick catch-ups

I’m writing this column in Philadelphia, just a few blocks away from Independence Hall, the site of Benjamin Franklin’s home, the Liberty Bell, and other historic landmarks. I’m attending a TESOL conference here with my wife Marty Kendall. She’s presenting some college programs she developed, and I’m the spouse tagging along. When the conference ends, we’ll fly to Jacksonville, FL, hop on our bicycles, and begin to pedal our way up the east coast! We love to travel this way. When we don’t have an aluminum and glass shell around us, and we don’t have an accelerator or brake pedal, travel becomes completely different. We feel the contours of the earth, we hear the birds, we smell the flowers and plants (great in April!) and enjoy the fresh, clean air. We carry iPhones and a small Garmin, so we are free to explore many back roads and trails.

When we reach our daily destination, it’s great to have a shower and a bit of wine (OK, we do carry just a little extra weight), play a fiddle tune or two, catch up with friends and work via our laptops, and sample the local cuisine. The food isn’t always what we might choose at home, but that’s part of why we travel. We usually post pictures from our trips daily on FaceBook. But, before we head off for our adventure, a bit more about …

more, More, MORE!

Last month I wrote about “maximizing,” a process that’s usually done to audio recordings during mastering. I described the sound (kind of like TV commercials that are much louder than the shows they support), the techniques for making it happen (software that turns down the loud parts and brings up the quiet parts, reducing the dynamic range) and the caveats (be careful about unwittingly changing the sound of that vintage D-28).

Today I’ll explain some techniques you can use to increase the apparent loudness of your projects while working in a systematic and careful way, so that you can make them louder without making them sound like AM radio.

Step-by-step, inch-by-inch, slowly I turned…

Before you begin to maximize your final mix, make sure that it is already at its highest possible level. Use the “find peak” or “gain” function of your software to see how loud the loudest part is, and then raise the entire track enough to bring that highest peak to just below digital max, (about -0.1 or-0.2 dB). When your unprocessed track is almost as loud as possible, you can proceed to work with your maximizing plug-in.



The maximizing plug-ins that we engineers use today include many adjustable and automated parameters. The most important parameter that you’ll need to work with when you experiment with maximization is the “threshold” parameter. “Threshold” describes the volume level above which the plug-in will go to work. For example, if you set the threshold to -3 dB, the plug-in will ignore all audio that’s quieter than that, and will only work on reducing the peaks of the audio that get louder than -3 dB. When it has reduced those peaks (usually imperceptibly, if it’s a good plug-in), it will have created three dB of open headroom, and will raise the track up to your pre-determined maximum level.

Learn by doing

Since you can “undo” many functions and processes in digital audio workstations, try this experiment. First, duplicate your mixed audio track and use the duplicate track for the experiments, in case something goes wrong and you unintentionally damage a file.

Using your maximizing plug in on the new (duplicated) track, lower the threshold control to -15 dB and process the track. Listen carefully to the results. It will certainly be much, much louder than the unprocessed track was, but what about the tone of the guitar? How does the banjo sound? What about the vocals? The fiddle? The mandolin? How is the overall tone of the mix now?

In most cases, when you use a maximizing plug-in to process an acoustic track as heavily as we just did, it greatly distorts the sound and feel of the track. One of the properties that make acoustic instruments so beautiful is the way they produce their sound – especially a property called the attack envelope. That’s the way the instrument’s tone springs out after a string is plucked or bowed. When the attack envelope is distorted artificially, we humans can tell right away that something is wrong. Devices that mess with the attack envelope are therefore quite dangerous around acoustic instruments such as those we normally use to pay bluegrass! In fact, all dynamic range compressors can really mess with the attack envelope as they reduce the peaks. So be careful when you use these plug-ins.

Let’s be reasonable

Now start again with a fresh, unprocessed copy of your mix. Use your maximizing plug-in again, but this time, place the threshold control at minus three (-3) dB. Process the track, and compare it to the unprocessed one. You probably will notice a healthy increase in volume, but not hear all the artifacts and distortion that were present in the version that was processed with a threshold of -15 dB. That’s because the threshold control told the device to work only on audio that was above the -3dB volume level. Everything softer than that was left alone, other than being turned up a bit louder.

So where should you put the threshold control when you are working on your own audio track? That depends on how your tracks were recorded, what they sound like, how loud they are, and what instruments are included. When I’m working with bluegrass mixes, I often find that a threshold value of -5dB gives me a nice, healthy boost in volume without damaging the sound of the beautiful instruments that made the track. You can experiment with your own tracks and see what sounds best. If you are new to discerning the differences I’ve been writing about, then be skeptical of what you’re hearing, and come back to the audio comparisons after a break of several hours. Our ears can truly become fatigued when we’re working in the studio, and breaks (even overnight breaks) can improve our perception.

It’s funny, but I find the same thing applies when I’m drinking wine. An overnight break provides a nice, clean renewal of perspective the next day. Off to get ready for a bike ride!


Joe Weed records acoustic music at his Highland Studios near Los Gatos, California. He has released six albums of his own, produced many projects for independent artists and labels, and does sound tracks for film, TV and museums. He recently produced “Pa’s Fiddle,” a collection of 19th-century American music played by “Pa” Charles Ingalls, father of Laura Ingalls Wilder, the author of the “Little House on the Prairie” book series. Reach Joe by calling (408) 353-3353, by email at joe@highlandpublishing.com, or by visiting joeweed.com.



 
Posted By:  Rick Cornish



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