(01-21-2020, 12:35 PM)vfr400racer Wrote: On the IRC, there was a discussion today, about the speakers being out of phase. Maybe this is the reason why the PBP sounds so badly, Maybe @Luke can check, if this is the case for a few devices only, or if all the PBP's are affected. A schematic drawing would be nice, so one can check if the speakers are connected the correct way.
There is a schematic on the Wiki. The speakers should have wire colors or markings indicating polarity. If they don't, you can test disconnected speakers by connecting one conductor to one terminal of a low voltage (eg. 1.5 V) battery, then quickly tapping the other conductor against the other battery terminal and seeing which direction the speaker moves. Do not run DC through the speaker. Just give it a quick pulse.