If you want to drive two pairs of loudspeakers from the output of one ampliﬁer such as the KLAB you can either connect them to a switchbox or wire them directly. If you use a switchbox then you can have the ﬂexibility of listening to either or both pairs as required. If you always want both pairs to be active then it is possible to wire them directly as long as you are careful with the connections. There are two ways to wire the loudspeakers; either in series or in parallel.
Wiring in series increases the impedance and will give a lower acoustical output. Wiring in Parallel has the opposite eﬀect of lowering the impedance and increasing acoustical output. When deciding how best to connect have a look at the impedance of the loudspeakers you are using and also at the speciﬁcations for the ampliﬁer. Most ampliﬁers will not work correctly with a load of below 4 ohms so if in doubt, always wire in series.
These example use only two pairs of loudspeakers. It is possible to combine more than 2 Speakers per channel. If connected in Parallel, (and assuming each loudspeaker has the same impedance) then the net impedance of the load is equal to the impedance of the one loudspeaker divided by the total number of loudspeakers. Eg 3 x 8 Ohm loudspeakers in parallel would equate to 8/3 (2.667) Ohms. If connected in series (and assuming each loudspeaker has the same impedance) then the net impedance of the load is equal to the impedance of the one loudspeaker multiplied by the total number of loudspeakers. Eg 3 x 8 Ohm loudspeakersin series would equate to 8x3 (24) Ohms.
It is possible to combine this approach and use a series-and-parallel arrangement to drive four speakers per channel. Assuming that all the speakers are 8 ohms then you could connect two sets of two pairs in series (giving 16 ohms) and then connect each series pair in parallel to give 8 ohms as seen by the amplifier. With so many pairs connected then speaker efficiency becomes very important as the amplifiers available power output will of course remain the same.