I've just bought myself an AVR200 and I'm keen to get the badboy going, but I'm unsure about the speaker impedance setting on the back. According to the Quad website, my 11Ls have a nominal impedance of 6 ohms, but it says they are 'suitable for use with 8 ohm amplifiers'. Should I leave the amp at the default 8 ohm setting or change it to 4-6? EDIT: my rears are Mission 771e - not got a clue about their impedance. Cheers.