"Shadow of The Colossus" build thread

[Legis]

The only thing that buggers/puzzles me is the 1,3khz dip with Faital. I dunno if the 1,3khz dip is due to Faital's own structure (some resonance?), Faital/Yuichi compatibility thing, or Faital's Qms/Qes is little bit too high to drive the horn as uniformly as Tad. I might test a less deep throat adapter what it does to it.

But very excellent sounding driver it is, just believe me on this one.

The impulse response is very clean due to non-resonant and very low energy storing behaviour of the diaphragm.

Tad has the hf peak which screws the impulse. I wish I still had the Truextent-Jbl measurements somewhere for comparison (in a different horn). My memory would say it also loses to Faital's impulse.

Faital vs. Tad zoomed-in:

 

[Legis]

Tried the Faital in the Yuichi without the 77mm long throat adapter. The hf response is predictably totally screwed because of the 1,4" to 2" step in the throat, but the 1,3kHz dip is almost gone (at all distances 50cm/100cm/listening spot).

So I will need a less deep throat adapter. 25-30mm long conical or even less?

 

[Legis]

Faital's phasing plug expands roughly 20deg per side (40deg total) if I calculated correctly, IF it were a conical/straight sided, which it isn't.


The soundwave also has to travel approx. 54mm before it exits the driver.


Perhaps I would need the help of Yuchi Arai to solve the optimal throat adapter for the Faital.

 

[docali]

Hi,

at Faitals official page about HF1440 we can read:

Exit Angle (5) Combined Exit
(5) The driver's exit coincides with the end of the phase plug, there is no adaptation throat.

I would read this as follows: The exit angle is nearly zero.

Following the original idea you would need two different sections. The first would be conical from 1.4" to 2" round to round as described for the TD4100 and then to respect the fin orientation with it's origin and opening angle a round to squared section. To do this should not be so complicated.

I assume this first conical section is indented to generate a defined spherical wave front and would also have some loading effects. I know someone who calls this correction section.

 

[Legis]

I have 25mm thick 2" circular to 2" rectangular adapter plate and the 77mm long 1,4 to 2" circular-circular throat adapter.

I also though if I just made a 1,4" circular to 2" rectangular adapter plate with smooth transition that is slightly longer than 25mm. Maybe 40mm. It would alse make the time alignment better by 62mm compared to whats it's right now (and more like what it was with usher horn).

The current 25mm 2" to 2" circular-rectangular seems unnecessary "straight" part in the whole when 1,4" exit driver is used, no?

 

[Ro808]

Tried the Faital in the Yuichi without the 77mm long throat adapter. The hf response is predictably totally screwed because of the 1,4" to 2" step in the throat, but the 1,3kHz dip is almost gone (at all distances 50cm/100cm/listening spot).

So I will need a less deep throat adapter. 25-30mm long conical or even less?

Yes!
It should be possible to calculate an ideal throat (adapter).
Perhaps a 'negative/inversed' extension of the phase plug, which does have some curvature. A hyperbolic-shaped adapter may work.

 

[Ro808]

This could also work, with the tip of the phase plug as the center of the HF1440's exit.

 

[Ro808]

In short: splines could be used which are then lofted in order to get a smooth transition to the throat of the Yuichi.

Obviously, the orange colored cylindrical part - including the phase plug - is what Faital calls "combined output".

 

[Ro808]

A290 Doc.

 

[Ro808]

Following the original idea you would need two different sections. The first would be conical from 1.4" to 2" round to round as described for the TD4100 and then to respect the fin orientation with it's origin and opening angle a round to squared section. To do this should not be so complicated.

I assume this first conical section is indented to generate a defined spherical wave front and would also have some loading effects. I know someone who calls this correction section.

This seems plausible.
It implies a duct transition.

 

[Ro808]

Came across some measurements of a naked TD4001 and attached to an AutoTech Tractrix 200 horn.
Shipping these from Poland to Japan should be horrendously expensive.

Unfortunately, the images are terribly small.

3&4: TAD TD4001 naked
5&6: TAD TD4001 + AutoTech Tractrix 200
7: TAD TD4001 naked vs. TAD TD4001 + AutoTech Tractrix 200

 

[Legis]

^That is certainly a Radian Al diaphragm used in Tad, impossible that genuine Be would drop that much in laser-tractrix and has an Re of much below 10ohm. Real diaphragm impedance around 11ohm at 5-30hz.

Also the beryllium 'phragm has rising response naked (hence it is straight even in constant directivity horn)

 

[Ro808]

Possibly, though he doesn't mention it.
The guy has a s..tload of TAD and Pioneer Exclusive stuff, but swapped his TL1601s for Audio Technology woofers.

TAD 1999 Pricelist:

 

[Legis]

Those Tad prices This one is also funny when checking the yen-usd rate around 1993, way under 10grand speakers: EXCLUSIVE model2401twin

Japanese stuff was undervalued back then, considered B grade as chinese stuff nowadays. Lol! Japanese hifi is the pinnacle of industry.

I also have 4pcs TL-1602b woofers in my Usher speakers, I plan to keep them "full Tads" with the td4001.

 

[Legis]

Take a taste of the (unoptimized) Faitals' sovereign calmness and ink black backgrounds. This is with full transistor signal path, xo-distorting pro amp and all (dac/amp worth 200€ total)

Link: Colossus - Etherwood - YouTube

 

[puppet]

I think it sucks .... that I can't hear it in person

 

[Legis]

Some more imagination exercise:

Hifi mix: Colossus - Hifi Mix - YouTube

Pop mix: Colossus - Pop Mix - YouTube

The amount of fun does not teleport to headphones even 10% with pop songs.

By the way, the comp driver has only 3,3uf series cap filtering in all these videos, not even a single resistor more. Slight ~2db presence boost results I love these Faital drivers even with the cheapest electronics and Spotify free quality source material (which was used). Ridiculous.

 

[docali]

I have a suggestion. Can you make impedance shots for driver / horn combos? Especially the Faital without any horn showing up to the ceiling and then with the long adapter and no adapter.

There are quite cheap adapter 1.4" to 2" around. You can shot one of them and attach this to the TAD adapter (round to square).

Have you checked that there are no leaks by attach the wooden adapter?

 

[Legis]

The Athos Audio makes a new adaptor plate for me which is one piece ie. 1,4" to 2" rectangular and 40mm deep (62mm less depth compared to 25mm plate + 77mm throat adapter). I hope it works like a charm both low and high.

It's too late here to measure tonight, but here's the impedance of the driver/horn combo, there is a clear dip at the impedance where the dip is in the response.

Yes there are no leaks, pieces are tight fits and Faital has a good foamy gasket.

 

[phase_accurate]

Your "neighbours" do also produce some nice stuff for dynamically capable speakers. "Coastal Ship" by Kari Bremnes for instance.

Regards

Charles