With modern computers and audio interfaces, it is easy to achieve
multi-channel audio. My notion of "Boom Box" surround
is an affordable way to achieve surround sound using two
existing portable stereos
or even two home stereos. The idea is to immerse the listener in
an environment using four speakers playing back four discrete channels (quadraphonic sound.)
A typical, portable CD/Stereo unit has two discrete channels of
audio. Therefore, in order to achieve quadraphonic sound,
two portable stereo
units are necessary. The result of this project is two stereo compact
discs or two iphones connected to stereo speakers, each programmed for one of the two pairs of speakers.
tracks on the two playback devices
should be identical in length, and started on their respective
units in tandem.
The image below illustrates the use of panning to make a source
sound "move." The
process requires at least two stereo tracks in any audio editor.
The top track (light blue) is programmed for the front left and
right speakers. The illustration represents the use of panning
through capturing automation
to cause the sound to migrate between the left and right speakers.
When the black line is at the top of the track, the sound travels
to the left speaker and when at the bottom, to the right. This
process is used on the bottom track (light green) to achieve the
of movement in the rear left and right speakers. It would be nice
to have the audio editor assigned to four independent channels
via an audio interface to hear the effect; however, with a little imagination it is not
In the illustration below, I have removed sections of audio to
remove the sound from one pair of speakers while it is sounding
in the other
pair. Fades are utilized for smooth transitioning between the pairs
of speakers. (more below...)
volume automation to cause the sound to move between the stereo pairs. The
example below illustrates volume as a means to cause one track to "appear" at
one pair, and then at another. The top track (light blue) represents a continuous
region of audio with automated volume control. On the bottom track (light green,)
a copy of the same region of audio is placed. The top track is intended for
the front playback device, while the bottom track is for the rear playback device. While
the volume automation is at maximum for the front track, it is kept at a minimum
for the rear. Combining volume automation with panning automation is an excellent
way to achieve movement with in the four speakers. On the top track, panning
automation is represented in gray. (more below...)
Upon completing the project, select the entire composition and prepare to compile
the multiple tracks into one stereo file. To engineer the content intended for the front playback device, mute
the tracks intended for the rear playback device and "bounce" or export a stereo file.
Then, without losing the initial selection, reverse the process by muting
those tracks not intended for the rear playback device and export a stereo file. Keeping
the overall selection the same for both "bounces" will ensure both
media files for the front and rear playback devices are identical in length.
Finally, prepare to playback the media for the front and rear playback devices, stand in the middle,
and press play at exactly the same time on both. Each unit should, although not
synced to each other, play in tandem. If engineered correctly, sounds
should appear to move around the listener's position.
are two example files, beesfront.mp3 and beesrear.mp3. Download
them and play them back in tandem using two different playback devices connected to two stereo units.