This question is like this one. I have two 1 ohm resistors, six 2 ohm resistors, and want 2 ohms total. All resistors must be powered (since they are actually speakers.) How do I do this? Ideally, a systematic way, or a computer algorithm should be presented to do this, but I am mostly concerned with the above problem.
I'd use a transformer like this: -
The transformer turns ratio would convert the 3 ohms of the inter-wired 6x 2 ohms speakers to 1.5 ohm seen on the primary. This, being in series with 2x parallel 1ohm speakers makes a total impedance of 2 ohms seen by the voltage source.
The turns ratio is 1:\$\sqrt2\$ by the way