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
@douglas_schroeder --

My favorites? None, if not set up well. Several, if set up well.
Over the years I am moving away from standard dynamic speaker towers. I am moving increasingly toward Open Baffle and Dipole (with or without subs). I can hardly stand the sound of a bass driver 8" or under; too earnest, too much popping of the driver when pushed. They just can’t handle LF and higher levels (Zero interest in arguing with people about this).

If you have poor amplification, you suck the life/quality out of the bass. If you have poorer cables, ditto. It’s a spectrum of performance, but also a spectrum of genres of bass technology - none of them definitively the best. YMMV

To me passive cross-overs, by and large, have a thickening and dulling effect on the bass (and the remainder of the spectrum), so active configuration is one step towards better performance here.

Going on from here I have no qualms stating that high efficiency 15" drivers are the best compromise up through the lower midrange, not least relieved of low bass reproduction when high-passed actively. Arguably the very best scenario in the power region - again, to my mind - is loading a proper 15" HE driver in a simple-fold horn (i.e.: not all too many folds), actively; this way the bass to lower mids will have an effortless "twang," smoothness, texture and dynamics that's simply unparalleled by any other bass principle that I know of. A "proper" 15" HE driver for this type of horn loading is rare though these days, if they're made at all other than by boutique, small scale manufacturers. Horn loading this way lends you ~105dB sensitivity, so the (15") bass driver cone will barely move at all, even at very high SPL's - not least when high-passed down low - and that's exactly what you want to achieve: less cone movement with high efficiency and lots of displacement area, not to mention via good air coupling. The only midrange/HF solution that can match such a bass horn is another, preferably large horn and compression driver combo, so there you have it; that's my preference, though it's not to say I can't enjoy a range of other well set up speaker principles.

However, it still goes to show that the typical love for smaller diameter, lower efficiency and direct radiating drivers comes down to convenience and what's most widely available; not a true choice per se. Who have heard a big, folded bass horn loaded with a 15" HE driver in their home - not to mention even bigger horn subs? Close to none, and so the predominant bias away from this segment of speakers is founded in conjecture or that it simply doesn't exist, and not actual experience. Added of course to the mere thought of having such behemoths placed in a home environment, that will no doubt scare most away. That, at least, I'm sympathetic to, though the lack of all-out and to hell with practicalities and WAF is still to be lamented. 
@Mozartfan
I was with you in the wideband hi-eff thread, but this 10" theory makes little sense. @auxinput gave you very important information. he's right. even a 15" hi-eff are limited in low bass due to the hi-eff design choice in building a hi-eff woofer. so a 95db 15" woofer need a BIG cab to make low bass: like 200L or more.

- no 10" wideband will reach 20khz smoothly. the rising response will be impossible to deal without compensations circuit to smooth that rising response

- a 10 inch wideband still need a light cone and relatively weak magnet= compromising low bass, and Ive heard a couple like the famous 10" vintage philips. they just dont do low bass

if you want a wideband and bass, look at FAST designs (fullrange-assisted-system-desing) at diyaudio. whole following there.

If you want wideband sound and real bass, you need subs. If you dont listen loud, get a 5, 6 " voxativ in a small sealed enclosure and try to make the wideband roll off naturally around 100hz, then integrate dual REL subs

hope this helps

PS: if you want hi-eff and real bass, go the classic way: hi-eff 15" woofer with a 6.5" hi eff mid and hi-eff 1.5" tweeter (seas t35 are 96 db) and go for a 1st order xo.
I’m building right now such a speaker with a Eminence omega pro 15", audax 170mo mid and hivi planar tweeter, 1st order series xo in a 200L cab. This system will be about 96 db efficient.
My wife say after having 6” and the 8” she like my 10” best of all. 
8" is a good. Mid-bass is a compromise so to minimize Doppler on the low end I needed 6 on each side, sealed box. Kind of blew the budget.

Then XO @ 58 Hz to 15" corner horns which is all right to 25 Hz for most music.

Then XO to the sub-sub 14’ T-line 4x15". Three of those. Flat to 4Hz. Could not measure dB. Had to estimate via Richter. Also doubles as a hair dryer. 

Couldn’t find the Hartley at the time of the build.
Full range drivers are always a complete compromise anyways where you sacrifice some aspect of the sound/characteristics to get what you want. It is actually incredibly difficult to engineer and manufacture a full range driver that really works well throughout the entire frequency range.


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Yeah I'm now firguring this  weakness of a  FR 8. Its super in the midrange,
But by itself, it does not have enough width and depth = soundstage was a  bit ~flat~~
so i pondered what can i do in the meantime while i save up some audio buget cash for the Vox 8...hummm, well lets see, I have the Thors collecting dust,,,thinking kind of liked something about the thors,,but not sure what the issue was that made me slam the Thors,,,so i figured since i have a  nice rich mids/some upper highs,,in the 8 FR,,thought i might as well disconnect the Millenium tweet ad run the other speaker cable to the Thors. 
BINGO, Soundstage returned very nicely. 
Just this moning wanted to ck what the dual W18's sounded all  alone on one channel and the other with the FR8,,,,sure enough the Excel W18 magnesius 87 db 6.5's were a  smash hit.
The lowes only go to 40hz. But what is so unique about this EXCEL W18 is the fq's between say 100-2000.
Here is where this driver really shines.
This super critcal range is voiced with no stress, no faatigue, just pure music.
I could not live without this W18 Excel. It simply must be in my system/ 
Now i note the Vox 8 is really FULL range,  that driver rocks, I know after countless YT vid listening sessions. 
How will the Vox8 intergrate with the dual W18's, Remains to be seen/= heard.

If the Vox seems a bit flat, I have no choice but to interfrate the dual W18's.
Will not mploya  compression horn tweet  either Davidlouis or 18 Sound. 
The Vox 8 has stunning highs. 
So taht saves me $400/DavidLouis or $650/18 Sound. 

Its good i did not dump the Thors for asking $800,  that would have been a gigantic mistake.
The new xovers, the cabinets, the dual W18's for $800?? I must  have lost my mind.
, , The tweeters will be dumped on Ebay, brand new for some change/ going auction style.
As per Richard Gray, **I hate dome tweets*. 
The dual W18's, really voice gorgeous in the upper bass, low mids. 
 Those W18's I could not live w/o.
The LII fast 8 FR is worth only what you pay for it.
The bass is a  bit thin and  mids  a bit too warm = muddy.  All my system is geared to be clear/ clean,  that is i attempt to eliminate all *warm*. 

 The LII Fast 8  will  have to do til I get the Vox8.