output / amplification

P.A. system

Electronic sounds that come from a computer are mostly sent to a PA system. A good P.A. system covers the whole hearable frequency-spectrum and represents realistically what the computer sends out. Sometimes it feels weird to have a big P.A. system sending out the effects of the acoustic instruments, because the scale is not right: the P.A. feels way too big for a piano, for instance, when the dry piano sound is not amplified. One of the solutions is to put one or two monitors close to the acoustic instruments and use only that as amplification. Like that the sound stays somewhat local: the effected signal sounds as if it is coming from the same place as the acoustic signal.

Local speakers

A consequence of using all the discussed ‘extras’ is a possible existence of signal latency, especially when using certain plug-ins (in combination with a lack of real-time computing power). Generally speaking a latency of more than 10 ms starts to feel uncomfortable/unacceptable.

Vitja’s approach to this is to mainly send his effected sounds to the front of house (P.A. system) speakers while another signal bypasses the computer and is sent to local guitar amps (one for electric signals, one for acoustic signals). Reasons for doing this are:

  1. This signal has zero latency and is meant to amplify the ‘dry’ sound (although it passes through optional pedals). The front of house signals are a tiny bit delayed (latency), but this doesn’t bother as these are mostly processed/derived sounds.
  2. In the worst case scenario in which a computer crashes, there can still be sound because of this computer-bypassed signal.
  3. The amp is a sort of monitor that relates logically and locally to the computer-effected sounds that enter the room.

Small speakers

The electronic sound can overpower the acoustic instruments very easily. This has as a result that the acoustic instruments do not feel big anymore in comparison with the electronic output. Mini amplifiers can be put inside of a grand piano for example, so the electronic sound can be sent to an output in the same physical space as the grand piano. As a consequence the electronic sound bleeds into the resonating strings of the acoustic piano and it becomes more of an interaction between the two signals, instead of two completely separate things. The Marshall MS2’s have a very lo-fi sound, which can be nice for some things: the clean sound of the computer gets a bit distorted.

In a little solo performance by Hendrik, the mini-amplifiers are used in combination with one PA-monitor. The mini-amps sending out a lofi/distorted sound, and the P.A.-monitor sending out a more realistic take on what comes out of the computer.

In the video below, Casper puts a speaker in the shell of the bassdrum and uses a mic to create feedback. Using the batter or a tuning key he bends the pitch of the feedback, making it into something musical and controlling the sound of it.

In general, the scale is the important factor to consider. In some cases you don’t want the electronics to feel almighty, but rather you want them to seem to be part of the acoustic sound world. Then you have to search for an output system that doesn’t have way more volume power than the acoustic instrument you’re starting from. On the contrary, sometimes you want to be blown away by overpowering electronics. In that case, you probably need a P.A.-system with subwoofers.

Panning and placing

When using a stereo image (left and right speakers), we can specifically place our signal within the horizontal spectrum or let it move from one place to another. We can do this manually or we can use automated panning devices (following an LFO or reacting to some kind of input).

In the next track we utilized a panning automation on recorded loop, making it travel around from left to right. Vitja’s sampler has this build-in feature with controls for speed and reach (how far you want things to pan – left to right and back to front). These panning instances can be used for four speakers (small surround system) as well. Notice in the track that playhead jumping is used on sampled recordings (the idea of randomly skipping in a loop), causing the existence of numerous soft clicks.

In general, the closeness/farness of amplified elements can be manipulated by (an absence of) artificial reverb. Hi-pitched or hi-pass filtered sounds will sound like they literally occupy a higher place in the physical space while lo-pitched or lo-pass filtered sounds do the opposite.

afbeelding doppler.jpg

The Doppler effect can be described as a natural acoustic phenomenon that occurs in moving objects. Approaching objects produce a seemingly higher sound than the actual sound source, while receding objects produce a lower frequency impression. In daily life we experience this clearly with passing sirens (of an ambulance f.i.). The Doppler effect is naturally produced on Leslie Speakers (because of their rotating horns). There are devices and plug-ins that artificially reproduce this effect when sources move in the mix, enhancing the lifelike nature of moving sounds.