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 ?



Do you have the required jumpers on the two pairs of terminals on the backs of the Polks? Red to red, black to black? 
What a stupid idea to put those cr*p Bose cubes on the sides! Stick to the Polks alone and throw away those Bose cubes!
Sure, you can connect the Polks and the Bose cubes in parallel. But the total sound will be cr*p! 
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Your Polks definitely need jumpers to work properly with just one set of speaker cables!
Yeah the jumper bracket is there. Am I losing power from the mains or not?
You are not losing power! But your sound quality will surely suffer from adding extra speakers! Otherwise get a 5-channel HT receiver and do a full home theater setup! And seriously, those Bose cubes are really cr*ppy sounding!
Stick to 2-channel (the Polks) or go home theater if you want extra speakers!
Yeah your not wrong they are pretty cactussssss......the cubes I just wanted to know if their was power loss. Because I was thinking of maybe getting bookshelf speakers. But I don’t want to get a receiver is their a way to hook up 2 sets of speakers to a power amplifier ?
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Only if the power amp has a switched set of outputs - Speaker A and Speaker B.
You could add a speaker selector box! I have one made by Adcom.
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?
Why do you want such a big, heavy amp to use with the Polks? How big is your room? The Polks are pretty efficient! Average listening will only be a few watts! An NAD 3020 V2 would work just fine ($400). 40 watts! And a built-in DAC for streaming!
If you had some Magneplanars the extra power would be useful! Otherwise you are just wasting AC power and increasing your monthly electric bill!
Speaker A means the LEFT speaker! Speaker B means the RIGHT speaker! The Yamaha is a PRO amp for sound-reinforcement in a concert hall! That's why it has the Phone plug and XLR connectors on the back!
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Speaker A = LEFT                                           Speaker B = RIGHT                                         GOT IT?
Yes, the POA-2800 has two separate speaker output pairs (red and black) per channel. Switchable from the front panel.