HiFi vs MidFi

whizzers allow for a   wider soundstage.
Rolloff? For sure, no big deal.
There are 1000 tweeters out there that can sing quite well above 5khz.
The only fq's I need from a  high end WBer are 40hz-12khz.
The 5khz-12khz from a  WBer are much greater soundstage presence vs any tweeter's 5khz-12khz.
But as for 10khz -20khz, here we absoluetly demand a  tweeter for ambience, sheen. 
Over lapping all fq's brought ina  unreal soundstage /presence to the music.
Diana Krall never sounded so good as when I brought in the DavidLouis W4 to pad up the DLVX8.
This is going further when i add in the DLVX6.
xover type speakers A-Z have this critcal band width problems at 1800hz-3200hz.
A WBers 3khz-5khz will always smash a  tweets 3khz-5khz. 
Its the nature of the beast. 
back in 2002 I asked about all speaker designs, flaws and +'s. 
No one even came close to my discussion of the obvious flaws of the xover types vs the WBer types.
Of course back then the 2 main WBers, Fostex, Lowther were not very good, not high fidelity.
Now fast forward some 20 yrs, now we have these high fidelity WBers.
Old technology born anew. 
The only commercial speaker that interests me are the Bache Audio Lab. 
Bache Audio Speakers will deliver the  finest sound in all areas. 
Outshooting Wilson, Dali, Zu, Tekton, Vandersteen, Sonus Faber, Tannoy
And all the other xover/ concentric designs. 
A-Z. 
WBers always win + midwoofer + tweeter.
Cohesive , seamless, full rich, dynamic, life like vocals, presence, lowest coloration, distortion ( these characterists all depends on which midwoofer Bache Audio employs, as I only  accept Magnesium, he employs some sort of paper, paper has some unwanted resonances)

Nope, wrong again. When implemented properly, they are no different than any other

~~~~~~~~~~~~~~~~~
Its a  known fact super tweeters/horn tweets have sibilance.
I HATE super T's.  The highs stick out like a  sore thumb. 
I believe the BA super tweet is some sort of Fostex and is basically a  compression horn.
= No go.
I prefer dome. Or my paper cone tweeter. 
Classical music does not need the 15khz=50khz  super tweet range.

Here ya go xover low sens speakers owners, Here is YOUR problem with your speakers.
Tangled up mess. 
Note Troels suggestions, make sure to use high end (=$$$$$) caps.
THese things ain't cheap, as i found out and only adds a  tiny nuance to tweeters , but a  nice size nuance to midwoofers in bass performance.
With my WBers, I do not have to deal with this xover headache.\
You do.
The type drivers Troel is refering to are very expensive.
Just a pair of any of his midwoofers and tweets , equals ,, no make that MORE than a   pair my WBers.
Add all his midwoofers + tweets + xover components together  then cabinets, wayyy out my budget.
And if you are doing one of Troel's 3 way projects,,Now you are up to Wilson size prices.

Not me. Budget cost for top high fidelity sound. 
Sonus Faber has a  2 way @ Sixteen G's.
wowow weeeee

http://www.troelsgravesen.dk/Design_criteria.htm

My WBers have zero distortion = zero fatigue.
This is a measurable fact


All speakers distort, they are the weakest link in the chain.

Back to the OP's all important Q.
This topic is the #1 topic of importance in all Audiogon at the moment, In fact I'd say this discussion is  THE SINGLE most critical Q in all Audiogon's history as a all thing Audio Discussion forum.

So we are speaking of  the only thing which makes a  system  True High Fidelity as defined by Philips Labs and that which lowers our systems to **mid fidelity** which really translates as anti-highfidelity .Which is really NOT fidelity and is what we all want to avoid.
Seas Excel are high fidelity, 
There's no arguing that point.
But at under 90db?
 nah, not my cup of tea, when  there are WBers with same high fidelity at 90++ db sensitivity to be had.

Jadis stellar amplification connected to a  Bose will only result in Mid Fidelity = anti-fidelity -= junk sound.

Speakers is THE component which determines whethera  system is high fidelity or the OPPOSITE *mid* Fidelity.
There is really only 2 camps. 
Is the speaker suffering resonances in the upper bass/low mids?
If the answer is 
YES
Then no amount of high end caps will fix the drivers  handicaps, Its crippled, has laryngitis, thus the Tenors notes are coughy, the bass guitar /drums have upper  bass fq/low mid fq's agitations.
Here is where all the coloration/distortions can be found as the culprit.
Midwoofers cone material. Also magnet size/type has some influences.
Cone material is the main culprit to lousey  upper bass/low midrange.

Next we have a  tiny VC tweeter attempting to sing low mids, under 2500hz.
Its acceptable as per Troels testing.
But a  tweeter 2khz-3200hz vs a  WBers' 2khz-3200hz. , Ridicuolous
Tweeters have lower than 90db sens vs a  WBers 90++ sensitivity.
Complete total annihilation. Due to 2 factors
WBer has a  much larger voice coil/whizzer + higher sensitivity.
Championship wrestling smackdown.

This topic is 
The most important topi9c, ever on all Audiogon, past , present and future.
Its ABOUT! D*** Time we get to the bottom of this issue.
Lets pretend this problem does not exist.
Lets play hide and seek.
Lets ignore the facts.
Sorry game over folks.
The WBer team won, walkoff  grand slam. Bottom 9th, 2 outs, 2 strikes. 
WBers reign as King Tenor Queen Soprano. 
No design can approach the WBers stellar performance. Not a  horn, not a  panel, not a  ESL. 
And especially *that other design** can't approach a  high end WBer. 
Caveat, we will need midwoofers/tweeters.