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Where do you find the Denon AV is 180W of power per channel? On the Denon website, the AVR-X3300W is rated at 105 watts (8 ohms, 0.08%THD, 20Hz~20kHz) and with high current drive. What does it mean? Is that 105 watts per channel at 8 ohms or total of 105watts combined for all channels?
The DEnon AVRX3300 hasn't 180 watts per channel available to it. You'd typically get between 80 to 110 watts per channel with only 2 channels driven while driving speakers with an impedance of 8ohm.
The speakers in question have a nominal impedance of 8ohm. Their sensitivity is comparable to that of most speakers so I'd not be too concerned about them being driven by the Denon receiver within a smallish room. Issues may arise if the room is larger than average though.
All in all, there's nothing particularly noteworthy about these speakers when it comes to driving them. They'd not need more power than most other speakers.
The rated power output at 105 watts is for 2 channels driven, so it will be less than that if all channels are driven. Your LSIM 703 speakers have 88db sensitivity and recommended amp power of 20 to 200 watts.
However, none of those stats really help to answer your question. Whether your set-up will sound better with additional amplification power depends on a lot of things. Such as the size and acoustic properties of your room, the volume that you listen at, whether you listen to music / movies / multi channel / stereo. As well as your expectations and your ears!
There are a few other threads on here where some people, me included, have found that even quite powerful and expensive AVR's can sometimes be out performed for stereo music listening, by power amps, even the very inexpensive pro audio ones.
If you are asking the question, it suggests that you are not completely satisfied with how your set-up sounds. The only way that you will know for sure if it will sound better with more power is to try it. Can you borrow / home demo / or trial a power amp in some way (sale or return?).
The rating is also not worth anything because it is relative to a frequency of just 1kHz and not over a 20 to 20,000Hz range. They've also increased the THD which is again not comparable to their other ratings. How many people power just one 6ohm speaker and only output a 1kHz signal?
Just live with the sound for a few weeks, let your ears get used to it. If you have to turn the sound down in your room then I suggest in power terms the 3300 is powerful enough. Could an amp improve stereo sound, possibly, but the 3300 is certainly good enough for your particular speakers.
If you are okay with the sound then the easiest thing to do is just enjoy it!
If you are curious to know if your speakers are capable of sounding much better with different or higher amplification you could try a pro audio (musicians / DJ) amp, which are very inexpensive to buy, and can sometimes even be hired. I see you are in the US, a Benhringer A500 for example is just $199 and available online so you may get a sale or return option.
You may not want to live with a pro audio power amp long term (although you could) but it would answer your question as to would additional or different amplification make a lot of difference to how your speakers sound.