How do you play the BassBoxes

When you are listening to the BassBoxes you are listening to four flutes, but the way these are used is very special. The sounds in the them are generated by the forcefull movements of the internal speaker, created by low frequencies from 0.2 Hz. up to 20 Hz. fed into the speaker.

To make and modify these ultra-low frequencies we designed a special low-freq. synthesizer and amplifier, the Pulsor.

Hans van Eck performing on the BassBoxes

The Pulsor

With the Pulsor we create and amplify the low-frequency signal which drive the internal speaker in each BassBox. As we have two BassBoxes, the Pulsor is equiped with two outputs (left, right) and the functions are designed double. Every part is built around two oscillators (LFO) which can operate independently, but can also be interconnected. The result can be panned between the left and right outlet. See the picture of the playing table:

The Pulsor playing table

The numbers refer to the different oscillators.

Tempo, ratio and levels

The vertical sliders in the middle marked with tempo regulate the frequency of his oscillator. His setting is translated into a midi-signal and sent to the midi-out port on the back of the Pulsor. This means that the tempo can also be controlled by an appropriate midi-in signal.

Next to the frequency-slider are the ratio-knobs located. ratio With this knob the turning point of the wave is regulated, this setting is also equipped with midi.

When the knob is turned left, the turning point is in the beginning of the wave: stand 0,
when the knob is turned right, the turning point is in the end of the wave: stand 127,
when the knob is turned halfway, the turning point is in the middle of the wave: stand 64.

The pictures are given for a triangle-wave, but the Pulsor can create a triangle-wave triangle as well as a square wave block. These signals can be combined in every proportion, the loudness of each is regulated by the sliders at the side of the playing table.

The signals of oscillator 1 and 2 are added together and panned to the left or right amplifier according to the level of the upper horizontal slider:

the panners

Oscillators 3 and 4 are regulated by the lower slider.


More complex is the way the oscillators can be combined: osc. 2 and 4 can be 'slaved' to osc. 1 and 3. The two left oscillators can regulate the behaviour of the right oscillators.

The way the right oscillator can be conbined with its 'master' is different for nr. 2 and 4.
The 'masters 1 and 3 can sent sent a sync-message every 1 - 11 full cycles according to the setting of the sync-knob: sync sent

Oscillator 2 can listen to the sync-messages from 1 or 3 and play 1 - 5 cycles in his own tempo according to its setting and than waits for the next sync-message. This technique is used in the composition 'House' to create the beat.

Oscillator 4 interpretates the sync-message in a different way: This one can also be slaved to 1 or 3, but it coordinates its frequency to the speed of the sync according to its setting: 1-5 cycles in the duration of the sync-puls.
sync recieve So with these sync-knobs you can create if you want to use them:
  • timed actions with oscillator 2
  • complex truplets with oscillator 4

  • Outputs and Inputs

    back of the pulsor

    The Pulsor has three different types of outputs and two types of inputs:
  • a midi-out and midi-in which makes it possible to monitor and record the playing of the performer, and to play the BassBoxes using midi.
  • the signals of the upper and lower oscillators as ordinary audio output on the two cinch-outs in the middle. This makes it possible to process this ultra-low frequencies in external processors
  • two external audio-in, two jacks in which you can feed audio signals to the left or right amplifier. Here the processed signals can be fed back into the system.
  • and of course the amplifier output which can be fed into the BassBoxes to drive the internal speakers.