PART TWO OF TWO
Now that you’ve built your own rackmount computer system as described in part one, it’s time to integrate this computer with all the other audio and video components you’ll need to produce a complete, operational DJ system. The computer selected in part one is designed to be light-weight, compact, reliable, and versatile. With its ability to be upgraded and modified as new technology becomes available, this computer should last for many years of good service without purchasing a new box. But a computer by itself will not provide everything you need for all aspects of your performances.
To ensure the ease of transportation and the ruggedness required for
mobile applications, all the components will be assembled into a light-weight, rugged fiberglass container. The case has a capacity of 10U spaces on top and 6U spaces in front. The bottom two front spaces will be occupied by the computer.
The third space up contains a 1U strip with right and left XLR audio outputs and 110 volt AC plugs for easy access to the powered speakers. This row also contains an extra 110 V AC plug and two composite video outputs (BNC jacks) from the mixer.
This homemade strip will allow convenient front panel hook ups for powered speakers and karaoke video monitors.
Above that will be two spaces used for the slide out tray holding the MIDI software controller. The top space will contain a 1U disc
player. This arrangement
allows for proper air circulation to prevent overheating. The importance of proper ventilation cannot be overstated; overheating is a real danger and could impact the overall system’s operation.
In the top section, the bottom four spaces have a flat piece of aluminum (painted black) where keyboard and mouse sit. Above that is the karaoke mixer for audio and video control. Next up is the four-channel wireless microphone receiver. After that is the AC power conditioner. The last rows are used for mounting the computer monitor and a DJ microphone. The whole system should weigh only about 35 pounds.
All AC power cords can be plugged into the AC power conditioner including the three front
panel power connectors
used for the
This will allow for
a single AC power
cord out the back
to be used to power
the entire system.
The API 1U CD/
DVD player can also
and CD+G formats. This can be used for karaoke singers who provide their own CD+ G discs or it can play standard CDs or MP3 audio discs, making it a CD audio backup player. The players? audio and video outputs can be connected directly to the mixer.
The VocoPro DA-1000 mixer will
accept two different audio and video input sources while providing two video outputs to drive projectors, large displays and singer monitors. A single button on the mixer will allow the DJ to switch between computer audio/video and DVD player sources. In addition, the mixer has three microphone inputs with separate echo effects for each mic. There are bass and treble controls for both the audio and microphone inputs. This is not a sophisticated, multifunction mixer, but it provides all the basic functions required by most DJs. You may decide to use another style of mixer if room permits.
It is possible to take the audio and video outputs from the DVD player and process them through the computer.
Richard has been an electronics hardware/software engineer in Silicon Valley for over 45 years, and is listed on several patents. During that same time, he has also operated as a mobile DJ, doing more than 4000 shows. Richard has contributed to the design of chips, graphics cards, audio and video systems, computers, and even satellites, as well as DJ lighting and sound equipment, while working for companies like Fairchild, Acer and Atari.
However, this is a more complicated procedure, and is not recommended for most DJs since it might impede the overall performance of the computer. The CD/ DVD player should remind isolated from the computer so it can function as a music source if the computer has a problem.
I use this system for 99% of all the shows I do. It can perform all the functions necessary for music, video and karaoke shows. I have over 100,000 music files, 15,000 videos and 10,000 karaoke files in this system (all backed up with two external disks). With the XLR audio output connectors, any size or combination of powered speakers can be accommodated by the system. If necessary, additional power amplifiers can also be connected to the system. Occasionally I will use a ?feedback eliminator? (they REALLY do work), when multiple microphones are used by members of the audience.
While this system is customized to my particular requirements and may not be the best choice for every DJ, it will still perform all the functions necessary for a great show, it is easily upgradable and extremely mobile. Of course you can design your own system using other parts to fit your particular needs; the overall idea here is to provide a very reliable and strong computer system for the average DJ to use. MB
Filed Under: Issue #147
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