Powering nine home speakers

I suggest you try this first:
Onkyo front left and right speaker outs --->  speaker selector with impedance matching ----> speakers 
Imo, when you parallel all speakers without impedance matching, it give a very low impedance for the Onkyo to handle! 

it references:
impedance protection circuitry
and
Impedance-Matching Autoformers safely distribute maximum power throughout your system.

The TSM8 and TSM12 come with autoformer and impedance protection circuitry, not on the ATM7!

Thanks again. Can I ask what’s the risk if the impedance doesn’t match (ie using the current speaker selector and a second amp)? Harm to the equipment or just uneven sound? 

Happy thanksgiving. 

jj91709,

     I think it's important you realize something that has not been stated on this thread thus far.  Listening to music through 9 ceiling mounted speakers is the least enjoyable method I, and probably most members on this forum, can think of .
     Your audio system configuration is fine if your goal is background music but falls far short of the high quality music reproduction systems that most members here use or are striving to create.
     I'm assuming you're fairly new to this site and may not be familiar with how to configure a system so that a 3 dimensional illusion is created which credibly portrays the performers as being in the room.  
     My intention is not to demean but to convey that there are much better methods to enjoy recorded music that I believe almost all music lovers would choose once they personally experienced the difference between a background music system and a properly configured stereo system.
     The members here are generally very knowledgeable and willing to assist those with less experience and knowledge (a minimal number of 'audio snobs').  
     I'm sure you'd receive good advice either way, but I think you need to decide if just louder background music or a more involving audio system is your preference.

Tim

Thanks Tim. This is just to fill the room. I have a dedicated theater already properly configured plus a recording studio so they’re very different goals. Take care