Currently use Onkyo Receiver TX-910. The preferred loudspeaker impedance is 8 ohms. I believe 8 ohms is preferred because the output impedance of the output line level is 8 ohms also. What could I do if I wanted to hook up speakers with a different impedance for sake of testing them out? For example, I want to use 6 ohm speakers. Could I use an impedance matching transformer? If so, recommendations?
Daniel, the Onkyo specifies 8 ohm speaks because it is unable to drive anything lower. If the 6 ohm speakers are quite stable, and do not dip below that too much, you may be OK. Onkyo has a very small power supply, thus the 8 ohm. Don't try 4 ohm.