Thursday, October 19, 2006

A Drum, a capsule, and a banjo - a multipart tale of Tizz

Around the lab we are constantly looking at the how and why of sound. Why does this device sound the way it does? How does the sound propagate and interact with it and how can we modify it to do what we want? These and other questions invade our minds and guide some of our investgations into things acoustic.

Of primary interest is the sound of ribbon microphones. We listen and listen and have convinced ourselves that ribbon microphones are objectively better sounding, with less noise, "tizz" and artifact than the "Large Diaphragm Condenser". We've also learned that acoustic transducers impart a sound quality that is similar to they way the moving element sounds when it is excited by a pulse source, in other words, the color of a microphone inherent to its overall internal timbre, and in many respects this is governed by the same phenomena that makes a good guitar, for example, sound good.

So here now over the course of the following week or so we take a tour into the sounds of Tympanic, Membranous Devices, or Drums, Capsules, and a Banjo, illustrated of course.

But first, we need to answer a common question:

What is "Tizz"?

Tizz is a noise phenomenon that sounds like its name - a ZZZZZZZZ sound that can be hissy, tinny or even boxy, that can be heard on a lot of recordings, and is most notably present in newer digital recordings of the human voice. We humans are good at hearing and identifying voices, and our perceptions are most acute when listening to the voice of someone we know. But this isn't so much about perception as it is about an artifact that occurs when a transducer is moved and lateral modes are generated. Tizz isn't caused by digital recording, but it sure is easier to hear nowadays. Remember our friend Chladni? Lateral modes are found in all transducers to a greater or lesser degree, and they can contribute to Tizz. Tizz rides under the signal and isn't very noticable on tape and at lower frequencies, but digital recording has unmasked tizz and set off a storm of people seeking vocal mics without it. Tizz is so common that it has becme accepted. People expect tizz which is sometimes referred to as "shimmer" and even as "air". But it's noise, and it muddies things up as it accumulates in multiple tracks, and it has become an affectation.

Listen for tizz and you will hear it. copyright robert j crowley


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