A normal Device\u00a0can drive 2 (Stereo) up to 6 (5.1) Speakers.\u00a0Using many\u00a0Players would not work without adjustment, even\u00a0slight speed differenced would sum up\u00a0resulting in chaos. So the Players would have to communicate and start each other at the exact right time. Instead we take a Stereo-Player, amplify it and then pass on the 2 signals to the correct\u00a0speakers:<\/p>\n
- \n
- set left channel to speaker\u00a01<\/li>\n
- fade in left channel<\/li>\n
- set right channel to speaker 2<\/li>\n
- fade in right channel while fading out left channel<\/li>\n
- when left channel reaches 0: set it\u00a0to speaker 3<\/li>\n
- fade in\u00a0left\u00a0channel while fading out right\u00a0channel<\/li>\n
- when right\u00a0channel reaches 0: set\u00a0it\u00a0to speaker 4<\/li>\n
- …<\/li>\n<\/ul>\n
![\"speakers_fortl\"](\"http:\/\/aboutmedia.notyet.me\/wp-content\/uploads\/2016\/10\/speakers_fortl.png\")
<\/a><\/p>\nThe switching itself was\u00a0done with relays. The fact that we switch amplified signal makes this easier. Not only we only need one amplifier, we also do not have to worry about unwanted clicks (chatter) while switching.<\/p>\n
As a player and control unit I decided to use a raspberry pi 2. As an amplifier I chose a hifiberry amp. [Experience on raspberry\u00a0and sound]. As speakers I found some nice small waterproof speakers.\u00a0Later we will see that we need 31 relays to switch\u00a0the speakers, so we can not (directly)\u00a0use raspberries GPIO [Experience on raspberry\u00a0and sound] to switch all of them. There are not enough PINs. So\u00a0I\u00a0used an Arduino Mega to control the Relays and got two 16 Relay boards that work well with Arduino. The raspberry is connected to the Arduino by USB, sending serial commands when to set what.<\/p>\n
So\u00a0meet the equipment we are going to work with:<\/p>\n
![\"alle_freigestellt_kl\"](\"http:\/\/aboutmedia.notyet.me\/wp-content\/uploads\/2016\/10\/alle_freigestellt_kl.jpg\")
<\/a><\/p>\nBeautiful, isn’t it?\u00a0We will have to find transparent housing maybe.
\nIn the next part<\/a>, I will describe the theory behind\u00a0the\u00a0programming.<\/p>\n<\/p>\n","protected":false},"excerpt":{"rendered":"
This project is an art installation that should generate sound wandering around in a room. For the room was small and rather\u00a0labyrinthine (in fact it was a toilet in a bar), it was not possible to use reflections, which is a nice possibility\u00a0in big clean rooms. So\u00a0the Approach was to use many (32) small speakers\u00a0spread … <\/p>\n