SS6 Speaker Selector Impedance Matching 2 Input 6 Output

I originally intended to order the SS4 model. Instead I perhaps made a overkill with the SS6 model. Anyhow, setup was a no brainer. Attach the left/right cables from the amplifier to the input terminals of the SS6. Also attach speaker cables to input output terminals of SS6. Took around 10 minutes to correctly separate a subwoofer, set of EPI bookshelf speakers, set of Bose 141 speakers with still room to spare. Still cannot figure out where in the 2nd input terminal coming from a separate amplifier should be. Perhaps there isn't another input but rather a set of output terminals to probably another speaker selector box? Anyhow, I can now select each speaker separately or play them all at once depending on the situation. Good solid product much comparable to what was selling at BB for twice as much and identical features. Right now, we have a choice of selecting the right set of speakers plus subwoofer for classical, jazz, rock and all sorts of music and video. Truly amazing.