Add speakers lose power ?


Hey guys my setup is pair of Polk audio rti a7 speakers powered by a Yamaha PC2002M 240 watts per channel and a Yamaha cx2 preamplifier. My dad gave me some Bose Acoustimass 5 series 3 cube speakers not including the subwoofer. 4 cubes in total. So what I decided to do was run some speaker cables from behind the Polk A7s because behind them they have 2 sets of red and white terminals, 1 set is already been used from the speaker to the power amplifier, leaving the other set free to biwire speakers, but I am not biwiring them I think? What I have done is used the other set of remaining terminals on the A7s and plugged in speaker cable and ran them behind my couch where I have floor stands on each side essentially rear left and rear right and I have 2 Bose cubes on each side. My question is if my A7s are 300 watts into 8ohms and the Bose cubes are 135 watts. But the way I have set them up does it mean my polks are losing power because the Bose cubes are taking the power from them theM? Because the way the Bose cubes are connected behind the A7s? Does that make my A7s lose power going down to only 165 watts?What do you guys think of my setup is it worth doing ? Any issues ? Or does it mean if the Bose cubes are using 135 watts from the polks the Polk will just grab more power from the power amplifier to replace power used from polks? So essentially still staying at 300 watts and the Bose cubes 135 watts no power loss in any speaker ?

Cheers


Tony

daoki
Hey roberjerman. If I was to get rid of the cubes and invest in some decent bookshelfs do you think it could be possible to hook up the A7s into speaker A of the power amp and the bookshelfs into speaker B of the power amp and then obviously switch on a+b from the front to produce sound out of all speakers. Is this a safer way of doing things you think? Surely it must be a more protective way if I was to set up 2 sets of speakers without a receiver and straight to amplifier ? I’m assuming my power amplifier would be able to handle this ? Other wise the power amplifier itself wouldn’t have the switch set if outputs speaker A and Speaker B?
Thank you for the pics! No, there are only outputs on the back for ONE pair of speakers! You will need an external speaker selector box (like my Adcom) to run two pairs from the Yamaha. But you cannot control the volume differently to the two pairs at the SAME time! 
This Yamaha amp will need RCA-to-Phone plug adapters to use the typical RCA-to-RCA cable. I have a set. You can buy a set online. Did you know this?