I was inspired to write this article when I received an email in regards to questions related to dual deck operation and I simply didn’t have the answers for this individual.  I’ve never operated one before and I found that I had similar questions.  After doing some research on the Internet, I came up with this article that covers the various features that are available for a number of different models.

Features

     Anti-Shock Memory is a useful feature present on the Numark CDN-34.  It employs a 12 second memory and requires a faster oversampling rate (speed at which the CD is read) in order to prevent skipping.  If the unit is shocked more then 6 seconds, the last 2 seconds of music simply repeats until the unit can continue.

     Most DJ CD units have instant start capabilities.  This is extremely crucial in beat mixing when precise activation is required.  It is the equivalent to “throwing” a record in order to prevent lag and to align the beat of one song with the beat of another.

     Another feature that most DJ CD units have is “auto-cue.”  This cues each cut to the first musical note to eliminate the “dead audio” at the beginning of the track.  This is also a handy feature that benefits beat mixing in order to achieve a precise mix.

     The CUE feature is present on almost every player and this feature allows you to store an exact position into memory and then start the track from that position.  This feature is useful when a “mix-in” is far into the track.  Clearing the CUE points from memory varies from model to model, but some models require holding down CUE for 8/10 seconds. (or a certain preset time)

    “Stuttering” is a feature found on the Numark CDN-34 and it allows the DJ to select a spot in a track to instantly re-trigger play start.  The first default is set at the initial cue point allowing you to hit the stutter button and automatically restart on the beat seamlessly.  The “Loop In” feature can be used to execute following stutters, which is great for seamlessly restarting a track on the beat to extend a fast approaching mix conflict.

     Seamless Looping permits the DJ to set loop points that are stored in memory and can be set and edited prior to playing a track or even on the fly.  The advantage to seamless looping is that there are no restrictions on loop length and it is very difficult to pick out the start and finish points.

     Pitch bend is usually included on most players, but the way it is controlled varies from player to player.  Some players have two buttons (one slowing down the track, one speeding up a track) each set to a preset pitch change.  When the button is released, the deck snaps back to its original pitch settings.  Some players have a combination pitch bend / jog wheel.  The jog wheel (slow frame search) is engaged when the player is in its PAUSE mode and otherwise it functions as a pitch bend. As well, most players have a shuttle search (ring control that searches faster when rotated further) for faster searching when using a frame search to find a cue point in a track is too time consuming.

     A backlit display is usually included giving current play status, loop status, single or continuous play, pitch change percentage, bpm, etc.  The modes displayed will vary from model to model.  Usually if there is a TIME button of some form, pressing this will toggle between “time remain” and “time elapsed.”

     In most cases, a wired remote controller allows the player to be controlled at a distance. (EJECT and CD trays in a transport unit and main controls in control unit)  This allows the DJ to mount the control unit near the mixer for convenience and the transport unit in the rack portion. (Near the amps, equalizers, effects, etc)

     Some models have continuous play (or repeat) which will infinitely loop the whole CD or individual tracks depending on how it is set.  “Program play” may be included on some models and allows the user to pre-program a sequence of songs to play.  This is very handy for times that you cannot be present at the booth.  You might also come across a feature that allows you to skip tracks by 10’s in the case of a CD that has 75 tracks!  Relay is a feature on some models that plays track 1 of the first CD, then track 1 of the second CD and so forth continuously.  This feature also allows you to wander off on a break, etc.  A transport lock is a cost-saving feature that prevents the arm that the laser is mounted on from being knocked out of alignment.  Additional features prevent the CD drawer from opening accidentally by disabling the OPEN mode when a CD is playing.  The STOP mode is also prevented from being engaged accidentally, it only engages when the STOP button is pressed for a preset length of time. (Usually 8/10 seconds, which normally would not accidentally be pressed for such a length of time) Some players will eject when the STOP button is further pressed the second time.  Again, this will change from model to model. Some players will have a “normal” mode that pauses after each track and a “continuous” mode that doesn’t pause between each track.  Depending on the model, several modes may exist.

Numark CDN-34 Dual CD Player