Metric Halo SpectraFoo Version 1.5 - Manual (Page 2)

Congratulations!
You are now the owner of the most powerful audio analysis and metering system on the planet.
SpectraFoo is capable of monitoring up to 24 separate channels simultaneously (depending on the speed of your Mac
and your input hardware). You may be asking 24 channels all at once? How is this possible? The answer is that
SpectraFoo uses Metric Halo Lab’s patent-pending high-resolution analysis engine. This technology uses the power
of your Macintosh RISC Processor in conjunction with your audio hardware to provide blazingly fast and incredibly
detailed sample-accurate Analysis and Metering of any channel or an entire mix. SpectraFoo technology is unique in
its ability to provide you, the engineer, spectral, power, and phase analysis which is truly useful to your production
tasks.
About This Guide
This guide is divided into three sections 1.The SpectraFoo analysis engine - This is an introduction to the underly-
ing technology behind SpectraFoo and how it differs from other Audio Analysis techniques. 2. SpectraFoo instru-
ments - This is an overview of the 12 types of track assignable Analysis instruments available in SpectraFoo. 3. Using
SpectraFoo - This section explains how you interact with SpectraFoo. SpectraFoo utilizes Metric Halo’s innovative
multi-window multi-channel audio routing technology to allow you to create multiple resizable instrument windows
that always remain active
Introduction – The SpectraFoo Analysis Engine
Welcome to the SpectraFoo Visual Audio Monitoring System – the world’s first audio analysis environment that
actually lets you see music. SpectraFoo is a high–precision, low–latency, fully realtime audio visualization and
analysis system.
SpectraFoo takes advantage of the phenomenon known as synesthesia. The word synesthesia, meaning “joined sen-
sation,” denotes the rare capacity to see sounds, taste shapes, or experience other equally startling sensory blendings
whose quality seems difficult for most of us to imagine. Very few people experience natural synesthesia. Those who
do usually possess distinct cognitive advantages over the rest of us. For example, many people with perfect pitch
associate particular pitches with particular colors. They see sound as well as hear it. The interaction of vision and
hearing helps these people maintain an absolute point of reference with regard to pitch. This allows them to discern
absolute pitch values without the need for a reference tone. SpectraFoo allows anyone to experience the benefits of
synesthetic sensation.
In order for the human brain to properly integrate multiple sensory inputs and derive greater value from them, the
inputs must be truly synchronized. SpectraFoo is the first audio visualization system to provide high resolution spec-
tral and phase information that is fluidly animated and absolutely synchronized to the live audio signal. It is the first
audio analyzer anywhere to allow the user to tap into the power of synesthesia.
Like many other audio analyzers, SpectraFoo’s analysis engine is based on the Fast Fourier Transform (FFT). The
FFT algorithm is an efficient means of computing a Fourier Transform on a computer. The Fourier transform was
developed between 1804–1807 by the mathematician Joseph Fourier as part of a study of heat transfer. The Fourier
transform converts a continuous record of amplitude vs. time into a record of amplitude vs. frequency. A modifica-
tion of the Fourier Transform called the Discrete Fourier Transform (DFT) was developed to deal with sampled
rather than continuous waveforms. The FFT algorithm was developed as an efficient way of computing the DFT on
digital computers.
FFT-based analysis facilitates highly precise measurements. As a result, it has become a natural choice for audio
analysis systems. Unfortunately, FFT-based methods have historically been more suited to Electrical Engineering-
type audio measurements than dynamic measurements of musical program material.
A traditional technique is to subject the system being measured to a known, controlled test signal. In order to get
high-resolution measurements from the analyzer, one must wait for a significant period of time while the output of
the system is captured by the analyzer and then transformed. If you want to measure the average response of the sys-
SpectraFoo Operation Guide 1