I have a Technics Receiver. I can do a test for all my speakers. Not sure where I should bottom the volume. 1/4 way up, 1/2 up etc. Should all the speakers be set the same or should surrounds be different? There are no markings on the side of knob. Also not sure which is best position (+12 to -12) after the test is done. Should all speakers be at maybe +6? When using Home Theater do you usually turn volume on TV down or mute it etc.