A full range speaker?

I've never made my self clean about the OP's Q;s 
Full range?
Does it really exist?
I tried to explain , but have missed being clear on the matter.
After speaking with Josh /Madisound on the phone yesterday, we were discussing compromises in designs. 
He mentioned something that i now see as so true
Josh brought up 1 of Murphy's Laws,
You can get 2 or the 3, not never 3 of 3 qualities ina  speaker. 
Now i see exactly what he is saying about Seas, vs Scan speaks midwoofers.
Its never been my intention to finda  speaker that has deep 20-40hz bass. 
Neither sweetest highs. No.
My main  searching has been for cleanest mids. 
Which is why i chose the magnesium.
The Seas magnesiusm's can not perfom as a Scan speaker mid.
Its a  different cone material
If you want rock solid drun solos, get Scan speaks

https://www.youtube.com/watch?v=z6B6WjAzuc8&t=4s


But somewhere you are going to have to make a  sacrifice.
I;'m willing to give up that rock solid punch, fora  sweeter  upper bass.low mids which I find the magnesium offers better.

Again, if you want nice sizzle and sparkle on the highs, get the Scanspeak tweeters.
I find the Seas , though not as sparkley on top end, has a finer body voicing vocals with STUNNING accuracy and perfection.

Again a trade off, the Seas lacks that sparkle and sizzle, but a  superior bottom fq reproduction.
.
Hope this clears up what I believe about the idea of full range.

Musicians performing in a room, captured with a "stereo" microphone (Blumlein)...

Playback: If you filter 35Hz and lower...

...you take away much of the "room" (the acoustical space) that the recording did capture and is capable of presenting back to the listener over two full-range loudspeakers.

You can spend more and get less.
IMHO anyone chasing after deep powerful bass, super sparkle highs,,  might end up witha  midrange 800hz-2k hz which may have coloration/distortion issues.
I don't know, Seas seems to understand these issues and attempts to achieve a  balance of the 3 fq ranges.

https://www.madisoundspeakerstore.com/approx-5-woofers/seas-excel-w15ch001-e0037-5.5-magnesium-cone-...

As per Millercarbon's comments on bass and harmonics I recall my late friend George Bischoff's comments. George was heavily involved in Pipedreams and Scaena speakers, both of which were definitely full range. He alsways said that to build a better woofer build a better tweeter meaning, of course, that bass quality depended as much on the bass notes harmonics as on it's fundamentals.

daledeee1, absolutely incorrect. Specs as published mean very little. They are taken at one meter in an anechoic chamber. At 3 meters in a real room the story is entirely different. Most speakers start dying at 80-100 Hz with a peak or two below depending on room nodes which results in one note bass.