All the IR sensors are in place for my random flange squeal system. Speakers are installed in the fascia, and I just completed a master control panel (see below).

The master panel will control random flange squeal on the three curves of the layout. The isolators in the upper left go to the three sound modules while the bottom row connectors will feed all the IR sensors. The system is designed to track locomotive speed so that the flange squeals only sound when a train is moving. When the train covers an IR sensor on either side of a curve, the sounds will play until the sensor is uncovered or the locomotive stops.