Need some Amp help - a little new to properly powering speakers


Hello. 

 I have some polk LSIM707s that I thorough enjoy.

However, at the moment I'm powering them using a Yamaha aventage 3070 receiver which at 150 watts at 8ohms sounds pretty darn good. 

However, since these are rated at 300 watts at 8 Ohms, I assume I will need some more power. I notice at lower volumes a lot of the imaging and clarity disappears. 

I am looking at buying a 300 watt emotiva Amplifier, or a 500 watt emotiva amplifier.

I'm assuming it would be better to purchase the 500 watt per channel emotiva so the speakers won't suck it dry or stress it. 

Am i wrong in this assumption? 
moskaudio
@moskaudio You are wading into a subject that will reveal different opinions fairly quickly. I try to get as much quality wattage as I can into my speakers without endangering either them or my hearing. My reasoning is akin, I think, to what you are expressing. For example, my speakers recommended amplifier power is up to 350W (8 ohms). I drive them with monoblocks rated at 430W (8 ohms). I have heard the speakers with an integrated amplifier (by the same amp manufacturer that makes the monoblocks) rated at 1500W per channel and they sounded great, although not as good as how they sound with the monoblocks, IMO. I would describe the effect as the amplifier seeming to have more reserve to allow dynamic recordings to sound abundant while maintaining excellent attendant speed. Of course, you don't want to crank the volume past a certain point or you will be buying new speakers. In sum, I think I'm practicing your assumption and I find it satisfying. And FWIW there is nothing wrong with your gear. It is your ears that hear it and if you enjoy the sound being produced that should always be what matters most.  
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I can see that. I figured a fairly expensive flag receiver would produce decent quality power but I guess I should try hooking these up to a 100watt per channel rotel amp I have and see how it sounds.
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Don't worry about the 300 watt rating on the speakers. That is a max level and no indication of what is needed to drive them in a particular sized room. If you can attain the volume levels desired and are happy with your amp/speaker combo then enjoy.