This is response with 18Sound 12ND730

This is response of B&C 12NDL76

First, tuning of band pass resonating part is quite high, around 150 Hz. That i don't know if worth.
The woofer is ment to go up to 300-350 Hz, being a part of 3-way midtop system.
I'm trying to model the horn that is more towars horn and less resonating, so i get a tighter sound, less springness & good eff. Getting a look to common BPH like ES18 and HD15 i noticed the very non linar response, that highlines the gap between the horn radiating and the resonating band. Otherwise l this non-linearity shown by HR response i never ever experienced in BPH like ES18 and USB, which i measured several time and i listen more than often. So What to do? Is it still good? Is the HR power response reliable? Should i lower tuning? Is NDL more suitable than ND730 in this case? Hother ways to design & model BPH if not HR?

No i didn't relized yet. I stopped buying from 18Sound last years cuz prices just have skyrocketed in 2017. ND730 doesn't appear in my 2017 pricelist, and i'm still waiting for the 2018 one, but i don't se any label saying its discontinued, pretty sad as was the one performed better.

Prices have not changed much in the last 5-6 years. Must be your dealer doing that.

About 18Sound, in my experience all prices have rised up a lot. There were more than one reseller here in Italy.. I had chance to get one 9601 for less than 400 €, get a look now.. Could be i am all wrong but i've been buying from different sources, and all are now more expensive. On the other hand B&C just keeps staying with same prices to me, lower than 18Sound.
EDIT:
ND930 pretty much the same as NDL76 as i expected. The point of my questions is about BPHs, and how far is the simulation from reality, if anyone of you have any guidline in designing that, according to the consideration i wrote and the already modeled one i posted.

So since 2010 the price have been increased exactly 5 euros.

You build a box, measure, tweak/build another one, or seven, until you do it right.

If it was that easy everyone would be building boxes. 

Ideally it would fit flush with the brace and the MF horn panels, so the HF horn wouldn't move at all from it's current position but the gap behind it would be filled in.

Probably too involved a process to retrofit, but if this is a prototype it might be something to think about. No acoustic benefit (well, maybe a very marginal benefit to the HF horn stability that would probably outweigh any negative impact to the BPH), but it could help the cab look more fleshed out/coherent.

If you could manage to get the HF horn sitting flush in this baffle that would be neater still.

I.e. the woods & braces behing top and bottom of HF horn are cutted out so the horn is fitting those 2 3 cm inside.

8" SH from ~ 300 Hz to ~2 kHz
1" CD Horn ~2kHz 

The aim of this system is to get a wide and best possible V dispersion, with a controlled and linear H dispersion, that is still narrower than V (enough to array 2 or more pieces without heavy combs).
Why wider V dispersion? It's for reagge/dub soundsystem, pointsourced at a fixed height, so not an ambient where versatility/sound reinforcement experiments are requied, and i wanted to design a speaker able to deliver a good and coherent translation of sound even 1/2 meters far from the stack, place where usually ppl dance as they get dat fatty bass, the juice of a dub/reggae party. One way is to easily angle a little FWD the tops cab, but it depends, not always is easy and pleasant to do.
So my researches went in asymetrical horns, and i learned is not a common topic, neither a proper way to do, as it ended up that is easyer to angle a symetrical horn rather than find complex geometries to bend the wavefront down.

Btw, i wanted to try, so reading a lot and modifying my initial idea, i finished to get that design + 8" cutted/molded phase plug (5 to 8 mm far from cone), that fills Vd of speaker and splits in two the paths vertically. That helped a lot in HF, cause horn has kind of large mouth, so off axis freq above 1 kHz were killed, on axis were killed around 1,5 kHz; more than 2 kHz after the phase plug. Directivity has gone as i expected, i got a something more or less good till 1.6 kHz in lower V axis, while it is killed above 1 kHz above V axis. I did these tests with that horrible prototype u see in first pic, but with the entire cab i got some refraction/reflection with BPH and i destroyed something in 1 kHz band, very sad as it was crucial point between what was good and what i achieved with ph.plug and horn modelling...

For may reasons (weak directivity results at HF in 8 inches horn mianly) i decided to move the cuts as this with these drivers:

15" BPH 15NDL76 - 280 Hz
8" SH 8PE21 - 280 Hz to 1.4 kHz (still to decide if to move up or stay like this)
1" CD horn DE550 mylar + XT1086 18Sound, same cut as above.

I now need to test the whole system with passive xvoer (from 15" to 8", very difficult decision that had to be taken) and i can spend some more words on final results.

This is how it looks now. The plug stays 0,5 to 1 cm from the cone.