6.5 vs 8 vs 10 woofer

OP you got their attention today!
I believe @larryi pretty much nailed it.

I fundamentally disagree with the notion that there is only one approach to any aspect of speaker design.......There are more ways to make a speaker system than there are ways to make lasagna--don't tell me that there is only one correct recipe, even if it happens to be the one I like.

So many different factors affecting quality of bass, not the least of which is acoustic suspension vs. bass reflex design, but also number of drivers, voice coil, magnet, cone material, surround, the box (size, shape, materials), impedance, crossover frequencies, sub(s) or not, and on and on.

Revelator sub working (9")

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Scanspeak  makes some beast like woofers, Monstas, Rip roaring bass drivers,,
But its not my cup of tea.
So to answer my OP q' a  8 is superior to a  6.5, <<obviously>> Buta  10 which has properly behaving, polite lower mids, is the ideal, if not most perfect driver for bass/upper bass.


So i will be going from dual 6.5's witha  mere ~disgustingly low~~ db sens of 87,,to a  single 10 with , ~~get this~~ 98db sens.. 
IMHO any driver below say 94db, is , at least to my ears, worthless old out dated technology.
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.
All those wonderful things Seas says aboutn their Excel speakers, MIGHT BE true, so long as there is no high sens wide band in the room.
When i get the high sens 10 in, the Seas Thors will not sound like Wet Blanket speakers, more like speakers covered in tar, Just ugly, real ugly.
Even the Diatone was blown away bya  94db sens, Each 1 db you go up the ladder, smashes the one below, 
db sens is everything  concerning speaker voicing. 
Scan and seas does have a  few high sens, but nothing that will compete with the new high sens drivers.
Those 2 labs are stuck in the 1970's technology. 

Thanks for sharing. Based on your informative post, I just put my two Rythmik F25s with their ridiculous dual 15-inch drivers out by the curb with a "free" sign on them. 

efficiency, though. You generally want a good 91db for one watt on the tweeter, preferably 92-93db efficiency.

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There are tons of choices of new compression horns which are 108-115 db efficiency. Why settle for a   dismal, poor efficient  93db, ??
Always seek high efficiency. Higher the db sens the superior the voicing of fq's This is a general rule , but more often true than not. 
In fact  now that i made the high sens discovery, its  my Golden Rule.
Thors 87db  lol 
You should go see what Seas says about their Excel drivers, In my book, none of which is true.  

I like many different kinds of woofer setups in speakers: multiple smaller drivers in the Revel Salon/Studio II and the Raidho’s, multiple larger drivers like in the Wilson’s, and right now using the 11” single Eaton driver in my Usher floorstanding speakers