Why does my mono block 1 channel amplifier have 2 terminals on it eg speaker 1 (+) (-) speaker 2 (+) (-)?
It’s a single channel amp. Having multiple terminals just makes it more convenient to connect multiple subs. The terminals are connected inside, so it does not make any difference if you use just one set, or both, or which set you use if just one. It only matters that you keep the impedance at or higher than the amp can safely handle. If you connect 1 SVC 4 ohm sub to each set of terminals, the resulting final impedance is 2 ohms. If you parallel 2 SVC 4 ohm subs to just one set of terminals, the impedance is still 2 ohms.
