Single driver vs traditional 3 way loudspeakers

Most of full range drivers have incline frequency response. And with a backloaded horn implementation they have a dip in lower midrange that causes dry and bright sound. To compensate it front horn should be added.
A good example is AER big transparent horn.

I don't have experience for adding super tweeters to full range. But with compression driver horns - 4th order crossover works 1000 times better vs 1st order crossover!!! Much less high midrange distortion, sound smoother more detailed, bigger and deeper soundstage, better clarity and separation. You can follow over interpretation more easy and enjoy music. I always used forward firing super tweeter and I did alignment for both 1st and 4rd order crossover implementations.

Here is the single good full range driver implementation without front horn I have heard.
Tune Audio Marvel
https://youtu.be/JCLuH_NeVgI
They use Fostex FE208EZ without whizzer and tweeter with big horn.
The crossover point between full range driver and tweeter is 2500HZ.

A huge system from Russia - AER driver with big AER transparent horn + 2 x 4 x 15inch bass drivers.
Start listen from 1:12
https://www.youtube.com/watch?v=WF_ZeYVgAf4&t=4913s

I used super tweeters with Altec 604E coaxial for many years.
I also listened Altec 604E without super tweeters for couple of years.
For last two years I use Fostex T90a super tweeters.
It is always was some trade off between “audiophile” sound with super tweeters and more “musical” sound without.
Super tweeters make sound more refined, more air, detailed… But harsh in upper midrange, more fatigue, more smearing.
But when I changed super tweeters 1st order crossover to 4th order – the results I got are win-win! I got all the best all together! The sound is even more refined, detailed with huger soundstage and clarity versus 1st order crossover. On other hand it smooth (no harsh, no smearing), even more musical interpretation details compared to without super tweeters configuration.

I think the same should be true when using super tweeter with full range driver!
I wonder, why most people use super tweeter 1st order filters? It Is so religion stubborn stupidity!

Most of classical speakers like JBL L300, Harbeth HL5 use super tweeters thought 3rd order crossovers.

Hi @mozartfan ,
High-Pass filter and crossover are the same thing!
You didn't read my message. I told that 4th order crossover (HF filter) fixes most issues with super tweeter.
I have to add that in case of forward-firing super tweeter placement should be aligned with the speakers. It is true for any kind and order of crossover (HF filter).
Regards,
Alex.

Hi @bache ,

Thank you for explanation.
I understand if you use full range driver you don't want to use it thought LPF.
With most of compression driver - midrange horn combinations high frequency response drops relatively fast and without significant peaks. So it is possible to separate frequency ranges between midrange driver and super tweeter if using 3-4th order HPF for super tweeter and don't need LPF for midrange.
     
I have a friend who is DIY speakers builder with many years of experience. When he built a number of JBL 4344 clones he always use 3-4th order HPF for super tweeter.
He told me to use 3-4th order when I bought Fostex T90a. But I didn't listen him in beginning.
And I now understand how right he was.

Regards,
Alex