The tapebow is, in its current implementation, a repurposed walkman modified to lower tape hiss and minimize interferences. The tapehead is attached to a mute, which must be firmly fixed to the bridge of the instrument.
The tapebow is powered by a battery pack and connected via a mono jack cable (3,5mm).
Very probably you will experience noises when approximating the hand to the tape-head or to the any other part of the tapebow. To avoid these noises, put the “ground ring” on one of your fingers (it just needs to be in touch with your body).
To be able to play smoothly (to make the tape more easily understandable) it has proven helpful to generate some “friction” to the movement of the bow (to make it less “jumpy”). One technique to achieve this is by placing a finger between the tape and the wood of the bow, as shown in the picture:
In order to have a finer control over dynamics, a MIDI expression pedal is used. Each string player uses a pedal, which is connected to a pedal board transmitting MIDI signals to the computer running the noise-reduction patch. A pedal-board together with three expression pedals are sent together with the material. The MIDI pedals can only be used with the rehearsal setup.
Some amplification can be used for the acoustic instruments with the objective of a better mix with the “electronic” instruments.
Violin, Viola and Cello play a tapebow and each have a dedicated speaker.
The output of each tapebow, after being processes as detailed below, is projected to a loudspeaker placed behind the player, so that she can hear the output as well (there is no risk of feedback)
The speaker does not need to be big, generally a good monitor speaker (like a Genelec 8260A) will be enough.
The resulting loudness should be similar to an acoustic instrument
To maximize the ability to identify the actions of each string player, the instruments, together with their dedicated speaker, should be placed as far as possible from each other.
When the tapebow is played very slowly, the resulting sound is mostly concentrated on the range between 20–60 Hz. It has proven helpful to use one sub to route this range from all three strings and filter this region from the signal going to the in-situ loudspeakers.
The percussion plays, among other instruments, a slinky attached to a resonating body (a snare drum, for instance). This is normally not enough amplification and some “active” amplification has been proven helpful. This can be in the form of a contact microphone attached to the resonating body. If general amplification is used, the output of the slinky should be panned to correspond to its position on the stage. Otherwise, a dedicated speaker should be placed near the slinky. Some slight reverb can be applied to counterbalance the dry sound of the contact mic.
The piano plays a MIDI keyboard connected to its own laptop (see below for details). If general amplification is used, the output of the keyboard should be panned to match its position on the stage. Otherwise, a dedicated speaker should be placed near the piano.
A tapebow has a very limited usable signal. Its headphone amplifier should only be turned up for practice. When connecting the tapebow to a PA system, the gain knob on the tapebow should be kept as low as possible to avoid extra noise.
The signal comming out of the tapebow is a stereo signal, in the form of a 3.5mm stereo jack. This signal should be routed to a mixing desk, each channel to a dedicated strip to be able to set the gain of each channel separately. At this stage we are using the mixer as a preamp. Adjust the gain until you see clipping from both channels. Let the player play multiple times to be sure that you got the maximum out of each channel (depending on the playing position, only one channel might be audible). Use the direct-outs to send both channels to the laptop’s soundcard for further processing (Don’t mix them down here, since you will have to limit a signal which will then be cleaned from noise later. It’s better to limit the clean signal after denoising)
The main purpose of this processing is denoising the tape signal. A denoising plugin should be used which allows to take a noise profile and substract this from the signal. In its current implementation, this processing is performed within the DAW REAPER, which has a builtin plugin for this task. Download the REAPER session from DOWNLOADS.
Within this session the two channels are mixed down to mono, then equalized to prevent humming, then denoised and after that a gate-compressing stage is used to maximize the signal. The output is a mono signal, which should be routed back to the mixer where it can be controlled during rehearsal/performance. This signal is sent to the dedicated speaker on stage.
The piano player also plays a MIDI Keyboard with at least 61 Keys. Since only the last octave of the piano is used, the MIDI keyboard can be fixed with tape on top of the piano keyboard itself. Otherwise, place the keyboard instead of the notes-stand, and use the stand of the keyboard itself to place the notes.
The MIDI keyboard patch should run on a dedicated laptop placed near the keyboard on stage. The output of the patch is mono.