Crossover Network with High Reliability for EV T35/K77-Klipsch Heresy/Cornwall wanted

[tiefbassuebertr]

Crossover Network with High Reliability for EV T35/K77 used e. g. in the Klipsch models "Heresy" and "Cornwall" wanted

It's about this tweeter from Electro Voice, which was available in different versions:
https://www.electrovoice.com/binary/T35A EDS.pdf
ElectroVoice T35 - anyone familiar with them?
『超高音』 Electro-Voice T35 第一版，與RP302、T350同級！ @ VAIGS-Natural Sound :: 隨意窩 Xuite日誌

In the attached images you will find schematics of crossover networks and responses as follow:
1) Frequency response from T35 Datasheet without crossover network
2) Frequency response from T35 Datasheet without and with X36 module (12db/oct)
3) Frequency response from T35 in Klipsch Cornwall from 1979 without crossover network - own measurement (L+R-Ch)
4) Frequency response from T35 in Klipsch Cornwall from 1979 with and without crossover network - own measurement
5) Impedance from T35 in Klipsch Cornwall from 1979 without crossover network - own measurement (L+R-Ch)
6) Klipsch Cornwall crossover network, 6db-oct 4µF - Attenuation-Inductor - 2uF
7) Klipsch Heresy crossover network, 6db-oct 2µF - Attenuation-Inductor - 2uF
8) Electro Voice X36 crossover network module, second version, 12db-oct 6µF 0,37mH
9) Electro Voice X36 crossover network module, 12db-oct 2,84µF 0,727mH

None of the circuit topologies uses a correct design, because in all cases the voice coil must convert too high levels in the low-frequency range into heat. That is the main reason for the well above average failures, so I think.
Only one capacitor as a crossover network (electrical only 6db/oct) is known to be particularly unfavorable.
But even with the second order filter, the possible variations (especially those caused by voice coil temperature) can totally ruin the sound - regardless of the quality of the components or care in making the crossover.
In my opinion two capacitors and two inductors are necessary to reach an acoustical LR-IV high pass filter slope with 24db/oct with an overtaken frequency of approximately 5KHz (-6db).
Only this step ensures sufficient attenuation and lower temperature increases in the lower frequency areas and better sound at the same time.

The question is, who know such a circuit for a pasive high pass filter.

Best thanks for advices.

P.S.: Another feature is noticeable:
Already without a passive high pass filter in front of the tweeter the frequency response looks like there is already a high pass filter with a 6db character present (slope at whole = 18dB/octave - usual are 12db/octave without additional electrical crossover network parts) What is therefore the reason ?

More URL's arround the T35
https://www.electrovoice.com/binary/BB1,2,3,4,5 EDS.pdf (URL dead - go to attachment)
https://www.electrovoice.com/binary/T350 EDS.pdf (URL dead - go to attachment)
https://products.electrovoice.com/binary/T350 EDS.pdf
https://m.review33.com/forum_msg.php?db=1&topic=69070827161929&start=4990&sort=1
https://forums.stevehoffman.tv/threads/electro-voice-speakers-the-best-in-the-day.151546/
https://web.archive.org/web/20101020064106/http://www.vintageev.com/docpage.html
https://community.klipsch.com/index.php?/topic/99140-electro-voice-t-35/
https://web.archive.org/web/20160912011437/https://old-fidelity.de/thread-862.html
https://critesspeakers.com/installation-of-the-k-77-t.html
ElectroVoice T35 - anyone familiar with them?

schematic X36 (crossover-network T35)
https://www.electrovoice.com/binary/X6_X8_X425_X825_X36_X336_X2635_Engineering_Data_Sheet.pdf
https://preview.manual.guru/preview...3/not-specified-electro-voice-x36/page-1.html
http://mypicsonline.net/archive/archives.telex.com/archives/EV/Miscellaneous Electronics/EDS/X8 & X36 EDS.pdf
http://audiokarma.org/forums/index....about-electrovoice-crossovers-rebuild.346860/
https://www.audioasylum.com/cgi/vt.mpl?f=hug&m=167947
https://community.klipsch.com/index.php?/topic/76828-electrovoice-t35-crossover-schematic-anybody/
https://audio-heritage.jp/ELECTROVOICE/unit/x36.html
http://audiokarma.org/forums/index.php?threads/are-the-electo-voice-t35-tweeters-any-good.648907/ (post #7)

 

[PeteMcK]

re:'who know such a circuit" - if there's an impedance plot somewhere in that mass of URLs, it should be easy enough to calculate....

 

[tiefbassuebertr]

re:'who know such a circuit" - if there's an impedance plot somewhere in that mass of URLs, it should be easy enough to calculate....

The design of a crossover network by calculation for a particular speaker chassis is generally impossible.
I use for such applications the CAD program "BASSYST" - go to
Beschreibung BASSYST
unfortunately the instructions for operating are only in German available.
Here my results (a listening test has not yet been performed):

 

[Cambe]

tiefbassuebertr,

Interesting.
OT: Have T35 in my 12trxb drivers.
Looking forward to your findings.