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

@Helomech, dynamics are the more appropriate adjective. There was some mid range and high range loss, but anything below -35DB on the Yamaha receiver (150 watt @8ohm) (which again, is a $1,999msrp receiver), had a LOT of dynamic loss.  

Then when paired with the Rotel Receiver (100watt @8ohm), the dynamics were more apparent at lower volumes. As the Receiver measures its volume in DB, the Rotel does not (0-100). Around 30, the Rotel receiver brought out more dynamics, and mid ranges that sounded lost with the Yamaha, at what was a much lower volume. 

I'm pretty new to this, but overall after doing some DB sensitivity research and other things, it's pretty safe to say that Polk LSIM707s definitely aren't the most responsive towers on the market. 

However, @Charles1dad, I think I'm gonna give a tube amp with them a shot. Seeing as how I'm new, the experimentation would be fun =). 

@Charles1dad, what tube amp would you recommend in or under the $1000 range? I don't mind buying used audio equipment on Ebay. I do however live in Oklahoma and needless to say....there isn't a whole lot of after market trading here. 

Also, I feel the need to thank everyone who has posted their opinions and thoughts here. 

It has helped broaden my understanding. I also read the research on the 1watt charts that were posted. I then looked at the emotiva amps and as someone posted above, I'd basically be throwing the same power that the Yamaha receiver is already producing which would indeed be a total waste. 

It is much appreciated 

Am I the only one, except Atmasphere, who thinks maybe solid state would be the better way to go with these speakers he's got?

Very few have done wrong by using tubes over transistors. My (now unused) 70watt KT88 tube amp drove my Spendors to deafening levels with serious bass. The Polks being 88dB at 8R should sound great with even a 30w integrated tube amp especially if the OP isn't cranking it.

Amojan,
It was atmasphere who made the positive comment regarding tube amplifiers in his post yesterday. Did you not see this? I personally believe that the key issue here is amplifier "quality " be it tube or transistor. People suggesting just get a more powerful amplifier (quantity) and throwing more watts at the speaker aren't  helping moskaudio (OP).

Moskaudio, I don’t have experience with tube amplifiers in that particular price range. I would look into known reputable brands such as Cayin, Quicksilver and Primaluna on the used market. Those 3 come to mind but I’m sure there are other candidates as well.
1 Regarding tube amplifiers qualify output transformers and power supplies are essential for good sound and performance.
2 Push pull topology with minimum 30 to 35 watts and up (assuming good quality) should work well for you. If you have to exceed the budget a "bit" I’d do it to ensure that the quality of the amplifier is good.
Charles