(Dartech also makes a more sophisticated version, Dart Pro 98. It's feature set additionally includes DeHum, real-time listening while adjusting filter parameters, a set of "smart tools," a printed manual, a recording timer-to begin capturing audio programs at a preset time, MP3 and MIDI support, and the ability to use DirectX plug-ins. Dart Pro 98 also costs $300 more. It's intended for professional recording studios.)

Main Editing Panel

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I evaluated this program from start to finish by recording "This is the Moody Blues" (Threshold Records, 1974), a double album that contains more than 70 minutes of play time. The album (which belongs to my wife) hasn't been treated very well. The intent is to clean the sound (deClick, deHiss), break the album into its constituent tracks, remove those songs I really don't like, and seamlessly record the rest onto an audio-capable CD-R diskette. (I intend to play the CD on a regular player, so converting the tracks to MP3 isn't part of the game plan. Nor is it possible with Dart Pro 32 - that function requires a different program.)

Installation required the reboot of the computer and the first time I started the program, I got the "Protection Check Failed" message. This is supposedly normal, except for the fact that I had the CD in the drive ready for the program to verify its existence. The second time, and all subsequent times I started the program, all went well. The program uses the "let me see the CD" type of ownership verification. According to the manual, roughly once a month the program will insist that you let it scan the CD to verify that you still own the program.

Each process created a new destination file (another 122Megs). There is a version manager (tree format) that keeps tabs on what processes were applied to each version relative to its parent.

For side one of this experiment, I executed a series of processes that were recommended by the manual: DeClick, DeHiss, time reverse the file so it plays backward, DeClick, and time reverse the file back to forward. Afterwards, I noticed a definite loss of "brilliance." One technique for reducing hiss is to reduce the levels of the upper frequencies -cassette tapes recorded using "Dolby NR" use this technique and during playback, Dolby NR re-emphasizes the high-end. So, for the final processing step for side one, I increased the top frequencies using the built-in 9-band equalizer.

Spectrum Analyzer

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In the spectrum analysis, you can see the high energy at the low frequencies. You can also compare the effects of the equalization (green-left, purple-right, before and after plots blended onto the same screen using Paint Shop Pro).

For side two, I wanted to try DART's "NoisePrint" feature. The sequence went: DeClick, NoisePrint, DeNoise, Highpass, then DeClick with smoothing. NoisePrint requires as little as two seconds of "surface noise," a section of the audio file where nothing but empty space can be sampled. This forms a noise baseline where, presumably, the entire album suffers from this, which can be eliminated leaving only the intermittent distortions. I also discovered my turntable suffers from a "rumble," high energy below 10 Hz. I eliminated that by passing only those frequencies above 100 Hz through a filter. Then I tried another attempt at removing some of the more well-hidden clicks by adding a smoothing function.

Watching the VU meters when playing the CD, on side one, the needles danced full-scale (high energy at sub-audible frequencies). On side two, they behaved as expected.

For all four sides, I selected and cut tracks that I really didn't care for. The total remaining time was well within the 74 minutes of available CD-R space. Selecting sections of the file was extremely non-intuitive. What seemed to work once wouldn't work a second time. Deselecting a section isn't as simple as pressing escape. It's CTRL-swipe to select, and CTRL-click (without moving the mouse) to reselect an infinitely small section, effectively no selection at all. As I tried and eventually succeeded dozens of times, I soon learned how to manage the selection process.

The other part of the Digital CD Recording Studio is Dartech's CD Recorder 4.0 Basic. The two programs look and feel so completely different, I wonder if DarTech didn't just buy someone else's application and stick their name on it. Oh, well. CD Recorder 4 Basic also includes most of the signal processing functions available in Dart Pro, but they clearly do not have the same level of flexibility and sophistication.

You create a playlist from your collection of .wav files (CD Recorder also includes a .midi- and .mp3-to-.wav file converter), set up any signal processing you need, and, if the .wav files are not in "CD format"-16-bit, 44.1 kHz sample rate stereo-they are converted to that format automatically when the Recorder makes a single humongous temp file. That temp file is then written to the CD recordable drive as an audio file.

Dart Pro's requirements include 1.2 gigabytes of hard drive space to record a 74-minute CD, and the CD recording unit must be SCSI, USB, or E-IDE. However, this experiment included using a parallel-port based unit and I made a successful recording.

Digital CD Recording Studio II, Professional Edition
$99.95 - Dec 15, 2000
ISBN: 1575954680
(Standard Edition, $49.95)
Macmillan Software
Dartech, Inc