A monoblock amplifier is a 1 channel amp (mono literally means 1). Since bass is omnidirectional, meaning you can tell where it's coming from, it isn't necessary to run subwoofers in stereo. you may see 2 sets of speaker teminals on monoblock amps and they will be labeled as either speaker 1 and speaker 2 terminals, or simply + + and - -. that is because the two + terminals are connected to each other inside the amp, as are the two - terminals. The second set is there simply to make it easier to connect multiple speakers to the amplifier. Do not confuse the two sets of terminals as separate channels. if you're not sure whether an amp is a mono or two channel amp, you can look at the labels above the speaker terminals. A multichannel amplifier will have the separate channels labeled as Left and Right, or L and R.