6.5 vs 8 vs 10 woofer


IMHO I think the 8 is the ideal size cone for mid/small sized listening rooms. Even for large size listening rooms. 
The lower mid hz's seem cleaner/clearer. And  there is so little fq's in 905+ of the music we listen to, it seems to me the 8  driver is the most perfect size cone.
A 10 size cone  has the potential to become overwheling, aggressive, attacking when amp gain is pushed just a  tad too much, = Better  volume  control with a  8 vs a 10. 
The 6.5 misses some of that lower bass which a  8 can voice superior. 
After listening to several YT vids with a  10 FR, I had considered going 10, but i think  staying with a  8 avoids regrets. 
I listen at low/mid volume. 

mozartfan
 Rythmik F25s

~~~~~
170 lbs of monsta bass,
I mean to ask, do you have neighbors, close by? Guess not, and your pets? Guess not. 
10 inch bass will provide MORE than enough bass in any size room. 
dual 15's ,  This is the bass The Who uses at rock concerts. 
"hate to repeat this 1m x's, but I'll say it one very last time, db sensitivity is 100% the most important tech value you ned to look at 1st in any speaker's performance."

While I agree with this sentiment 100%, there is always the exception to the rule.

15 years ago, I was in a band, and we were getting ready to do our first headlining show.  It was a small club, and we had to supply our own PA.  I advocated for us to spend fifty bucks (we were getting paid $400 for the show, so this was not a big deal) to rent a couple of mains, since one of our supporting bands had already agreed to bring a pair of their monitors for the gig.  

Our singer was stubborn, though, and was combing Ebay as hard as possible to find a different path.  One of the things I told him was that efficiency was a VERY big deal with loudspeakers, because the lower the efficiency, the more power we needed to drive them, and I didn't have unlimited amplification capabilities.  

Lo and behold, he finds a pair of mains ($100 for the pair plus $100 shipping) claiming 500w power handling and 98dB efficiency.  I told him it sounded fishy, because there would be a ceiling on max dB output, but he went ahead with the purchase.

The voice coils caught fire less than half an hour into the first band's set.  LITERALLY CAUGHT FIRE.  All we were running through them was vocals, so there's no explanation for this other than they were just cheap, shitty speakers, no matter what stats they claimed.  
Well, I combine those with a pair of SVS SB-13 Ultras to make sure there's just enough bass.

They all come with volume controls. They don't have to be turned up to 11.
Wow!  I'm Not Sure..  Crazy!  the time we all have that is Free Time, on this..  is All..
I remember way back when...before the popularity of (invention of home) subwoofers... 8" was considered the 'proper' woofer size in many a sealed box 2 way system. 
I also agree no one size fits all!