Groove

Computer DJing via Digital 1200SL MP3 Player


by iJAM Productions Inc. (A.K.A. JAM)

Being raised on Lost in Space, Star Wars, and The Jetsons, I've longed for the day when I could beam my entire DJ setup over to an event ... who wants to carry all those records, turntables, and mixers? Although that's not in the cards just yet, MP3 data compression (see sidebar) brings us much closer to that ideal.

Sure, some DJs are already forsaking tapes, CDs, vinyl, and videos as ways to promote themselves for gigs. Instead, they create high-tech multimedia demonstrations on notebook computers (backed up by a live mix on the system during the presentation). But now the computer can actually become part of the DJing process with VisioSonic's Digital 1200SL MP3 player ("PCDJ" for short), a computer-based professional DJ system. The software "virtualizes" a pair of turntables, a mixer, and a record case on your computer screen. After encoding your music collection to MP3 files and storing them on a big hard drive, you can use PCDJ to set up your playlist, crossmix between tracks, change volume levels, beat-match one song with another, and so on. The interface is so friendly it's like working a real-life system, but with finer control. Interestingly, this doesn't make for a less creative experience; in fact, having everything in one place lets you really focus on the musical flow.

Installation and setup is easy. The software auto-tests the PC's sound cards and generates a list of PC settings that tech support can use if there are installation problems. Copy protection consists of e-mailing or calling the company to "unlock" the software.

VisioSonic recommends two sound cards to allow main and cue stereo outputs, but the system works with one sound card if you can forego cueing. PCDJ supports WAV files, MP3, the new Xing VBR MP3, and Encrypted MP3. Commands can be triggered with MIDI note-ons (e.g., a keyboard controller patched to the sound card's MIDI in) for exceptionally fast response. Currently, note assignments are fixed, although you can use any MIDI channel. Audio processors (such as an EQ) patch between the mixer and amp, as usual. The system is password-protected to guard against unauthorized changes while the program is in operation. Also, encryption of the encoded MP3 files makes them safer from theft and piracy.

Cue Me Up, Scotty

Unlike mechanical devices, the PCDJ offers real-time instant start, cueing to within 0.01 ms, pause with "audio looping," and up to 20 cue points for each track. (You can see, as well as hear, the cue points while editing cues.) The "Auto Cue on Stop" feature skips the silent part at each track's beginning and end. For precise beat-matching, there's a "match pitch to BPM (Beats Per Minute)" conversion button; the program's metronome-assisted BPM counter allows you to determine a song's tempo (if the tempo changes, you naturally need to re-adjust). Pitch controls for each player range from +4 percent to Ð52 percent, and a mini player allows auditioning a track directly from the record case without having to load it first. And where do you get those MP3 files? The PCDJ does audio extraction from CDs, using a fast encoder.

However, there is one major limitation of this technology: You can't use dynamic scratch techniques unless you get really facile with the pitch control or create an MP3 scratch file as filler at a particular cue point. Even then, it doesn't come close to the real theatrics of scratching. Also, the system is picky about what CD drives and sound cards you can use (see EQ Lab Report). While other devices can work, VisioSonic guarantees optimum performance only with the recommended components.

On the Fly

The PCDJ's labeling, grouping, and find capabilities simplify mixing on the fly. There is a search engine for the track database, and you can create an unlimited number of groups and subgroups in the record case to store links to tracks on the hard drive. Removable media subgroups are sortable by BPM, title, artist, version, or comment, and DJs can easily tag edit with the new ID3V2 Version 3.0 tag standard. (This simply means that each track can be tagged or labeled with information about the artist, song, etc., which will be displayed in the "record case.") You can name each cue point to make it easier to find.

To get an idea of how the process works, from a category of twenty to thirty songs incorporated into a specific playlist, you can drag and drop titles in a pre-selected order and load them into both players (A & B), similar to what happens with CDs and vinyl. From there, mixing and matching the beat from one player to the other simply requires pressing a button to set your next track to the same BPM, adjusting the pitch control to your desired key, bringing up the volume, and tagging the beat. It's almost an automatic mix. Of course, slam mixing and dropping works just fine as well.

Travel Light

You can put your entire music collection in a laptop ... with a 10 GB hard drive, the PCDJ holds well over 3,000 tracks at 192 Kb VBR. There's even an Auto Pilot function that automatically plays tracks from the record case should the DJ not make it back in time for the next mix. Overall, the PCDJ has been a great tool. Many large radio broadcasting companies have used MP3 technology for years; now this reliable compression format has made its way into the mobile and club disc jockey market. MP3 technology gives me the ability to mix easier, but the PCDJ allows me to "mix smarter."

[Note: A "junior" demo version, PCDJ Phat, is downloadable from VisioSonic's Web site.]

From a meager start as a vinyl disc jockey at a local roller rink in 1973, iJAM Productions Inc. has become a full-time entertainer, and owns the Florida-based company, "A Spinnin' Crazy Production." He is often found speaking and demonstrating at DJ and music conventions, and his level of community involvement has made him one of the few mobile disc jockeys entered into the Congressional Record.

MP3 BASICS

MPEG (pronounced "em-peg") stands for Moving Picture Experts Group, an industry standards group that defines universally compatible ways to code and transmit audio and visual information. MPEG is also a sophisticated technology that compresses and transmits music and video over networks (satellite, the Internet, and telephone) with minimal loss of sound or picture quality.

MP3, an extension of MPEG technology, specifically covers audio file compression and storage; Layer 3 is a third-generation coding standard that can produce near-CD-quality sound, while requiring only a fraction of the amount of disk space used by uncompressed hi-fi audio. Quality varies with the compression ratio (typically 5:1 at the high end to 22:1 for low-fi applications).

MP3 compresses data by analyzing a file's audio and not coding sounds that it deems imperceptible (e.g., sounds masked by other sounds). Discarding unnecessary audio information saves tremendous amounts of disk space, and the fidelity remains acceptable for all but the most audiophile-oriented applications.

There are two main encoding processes, VBR (Variable Bit Rate) and CBR (Constant Bit Rate). With CBR, the bit rate stays constant. With VBR, the computer analyzes the song being encoded and changes the bit rate on an "as needed" basis, attaining the maximum bit rate only when requiring maximum fidelity.

MANUFACTURER: VisioSonic, 21939 US 19 North, Clearwater, FL 33765.
Tel: 727-799-3828
Web: www.visiosonic.com.
APPLICATION: Professional DJ mixing where portability and control are paramount.
SUMMARY: PCDJ brings the professional DJ to a higher level of technology, offering exceptional capabilities and ease of use.
MINIMUM SYSTEM REQUIREMENTS: Pentium II or AMD 300+ MHz (no Cyrix chips), Windows 95/98, 32 MB RAM (64 MB RAM for SoundBlaster Live sound card), 10 MB hard disk space (more required for MP3 songs), 20X CD-ROM or above (must support digital encoding), one SoundBlaster Live or two Turtle Beach Montego A3D Xtreme sound card(s), 800x600 SVGA/256 color display.
STRENGTHS: Simple to use. Beat match capabilities with the press of a button. Thorough, readable documentation. Easy setup with auto-testing. Instant start. Integral search engine. High-resolution cueing. Supports dual sound cards for cueing. Includes CDDB (Compact Disc DataBase) functionality.
WEAKNESSES: Requires particular CD-ROM drives and sound cards. No scratching.
PRICE: Software PCDJ PHAT Digital 1200SL $199; rackmount system with computer $1,699; mini-tower version $1,099.


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