definitive technology sm55...sounds harsh especially dialog.
Amp - Emotive basx a3 three channel amp
Some things to try first before replacing stuff:
- Post PICTURES of the room/setup so we can see how much room there is (to
@lovinthehd says) , and how your center channel is mounted/aimed.
- Measure your loudest SPLs at the listening position. At least with a phone app that can do unweighted (not "A" or "C"). And how far is that, as
@William Lemmerhirt asked? This is to determine if you are even close to clipping.
- Swap your SM55s around, to be sure there is not simply a problem with the center one.
- Do you really mean HARSH as in distorted? Or UNCLEAR and hard to understand? Those are two quite different things.
Then
- Since human hearing is logarithmic all AVRs have essentially the same power. 60% more power is only one small volume step. To have significantly more power means like >300W/4Ω which as
@lovinthehd pointed out the Emotiva BasX do NOT make the grade. You'd need like
https://www.buckeyeamp.com in 3 channels, or a 4 channel with one channel unused which is OK also.
- You would also need preamp outputs which then means yes changing the AVR. Now with amp and AVR you have spent most of your budget.
- As a loudspeaker engineer my vague rule of thumb is you have to spend 3X to be pretty sure to get to the "next plateau" of sound quality instead of just trading off inaccuracies. You will not have enough budget left to do that. And Definitive are good designers,* you'll really need to step up.
https://www.stereophile.com/content/definitive-technology-studiomonitor-55-loudspeaker-measurements
shows they are fairly sensitive although not the MOST sensitive. Rather than more power more sensitive speakers would be the way to go HOWEVER:
- Speaker specifications are worthless nonsense, you cannot compare across brands due to different measuring setups and different levels of lying by the Marketing Department. The "watts" are also ridiculous; speaker power handling is flat out too complex to distill down to one number. Sorry!
- Sensitivity is how loud per watt the speaker plays. This is limited by the woofer size pretty much: the bigger the woofer the more sensitive it *could* be. Just because something has a horn does NOT make it sensitive. Klipsch with 2x10" woofers in a big cabinet? The spec may be ridiculous but yes still significantly more sensitive than regular speakers. Klipsch 5" with a little horn? Not gonna be special in the sensitivity department.
Therefore we need the answer to the question of how big a speakers you can fit into the space, to recommend something more sensitive and with hopefully less distortion.
*Measurements show some funkiness around the crossover point. This is inevitable in a 2-way dome tweeter design, so 3-way may be better for you. Alternatively horns/waveguides roughly as big as the woofers can get rid of some of those problems.