Studio: Tracer Technologies, Inc.
Video: 1.33:1 Color
Audio: DD Stereo
Extras: Audio test booklet with chapter summary and brief quizzes
Length: 130 minutes
Rating: ****
This disc is marketed as a college level audio introductory course for the non-scientist (i.e. without mathematics). As an attempt to teach technical issues to non-technical people there are slides, audio graphs, charts, a booklet with chapter summaries and brief quizzes, and a narrator who will occasionally throw a bit of silly humor in the mix. Although most of the discussion makes logical sense, there are some points that, due to the lack of mathematics or rigorous demonstration, the narrator will say something like, “You’ll have to believe me on this one.” Often he is attacking myths about the inherent limitations of digital audio (such as the inability to correctly capture a 19 kHz wave with only 2 sampling points), but there is no hard proof other than the offhanded comment. Of course, this is meant to be a fun, educational video and not an end-all be-all on the subject. One of the assertions on the disc that many would disagree with is that most people cannot hear less than a 2 dB difference.
Almost all of the material has been discussed on many occasions in different audio magazines over the years and is available in book form in physics texts or even introductory guides to digital audio. However, no one can argue that a DVD is a much more palatable medium to receive this information. The quality of the material presented is slightly better than a Power Point presentation. Occasionally, it was hard to see certain graphics, read text, and the audio wasn’t always perfect. The software used by the narrator is a software package called Diamond Cut that Tracer Technologies just happens to sell. My burned copy of the Audio Movie had difficulty playing in one of my DVD players, but I can only assume this was related to my review sample. (The accompanying booklet was also just a photocopy.)
The disc is broken down into chapters and when one is completed, the viewer is returned to the main content menu. The disc encourages viewers to take the process slowly and only view one chapter at a time in order to best process the information. The chapter breakdown is:
2) Sing A Song Of Sine Waves (4 min)- discussion of sine waves and how complex sounds are made up of them.
3) Dialing In The Frequency (6 min)- Hertz, bandwidth, and accepted audible range of sound.
4) Time To Get Amped Up (16 min)- the Bell, the dB and logarithms, real world amplitude and computer (negative) amplitude scale, threshold of hearing, and volume changes related to dB.
5) Are You Master Of Your Frequency Domain (17 min)- fundamentals, harmonics, and square waves, spectrum analyzer and FFT process, phase, and the Moog synthesizer.
6) The Pitter Patter Of Little Bits (21 min)- sampling, bit width, binary numbers, and resolution.
7) Sampling Rates Exposed! (23 min)- sampling rate, Nyquist Frequency, aliases, and the history of 16bit audio.
8) Advanced Sampling (16 min)- anti-aliasing filter, filter slopes, Total Harmonic Distortion (THD), and higher sampling for improved sound.
9) The Pyramid Of Knowledge Grows (24 min)- quantization and quantization error, dither and noise shaping, advantages of digital recording, compression and MP3, psychoacoustics, and artifacts.
10) The Finish Line (3 min)- a recap of the material covered in the DVD and a plug for Tracer’s website and the next disc in the series—a disc on audio restoration.
I was familiar with almost all the material, so it would be hard to judge exactly how easy it would be for a truly non-technical person to pick up the information. The pace seems good and the narrator does linger on more difficult topics to ease the understanding of the viewer. Still, I did manage to pick up some information that I had either forgotten about or never knew.
As an introduction into particular elements of audio, the disc does a nice job and my chapter summaries should give a good idea what content is on the disc. However, there is little done to extend the material to include information that may be of practical use to the consumer when looking to purchase equipment.
A disc I’d like to see would include an explanation of specifications of audio electronics, video components, speakers, system matching, cable selection, acoustics, signal flow, system setup, etc. There are some how-to guides online and in magazines, but this seems to be the area that gets the least attention and is of prime importance for most people. You’d be surprised how many people have no idea where to put a speaker or how to connect components to each other.
— Brian Bloom
