Tekton style like tweeter array good idea?

[OldHvyMec]

The thing I can't see getting around, is simply how to get drivers to tight pack together so 1/4WL coupling occurs, through the freq spectrum.
Best illustration of that l goal I've seen is this...snipped from a TDanley patent.

There is an issue with magnets being so tightly packed in an array like that. I've used this concept on two occasions in DIY apps.
I'm almost positive is was the same less the exact drivers. 1996 or 1999.
A lot of work for very little result. It just doesn't work because of the number of drivers. Truly a masterpiece of complexity for
no reason at all. The time to make that! You could build the Space shuttle quicker. LOL

One of the very neat things about concentric drivers Ellipticor A50 Scan-Speak it covers all the bases an array like Mac. Tekton
Polk, Bose, and many more try to cover with multi-driver concepts. They won't fill a stadium, LOL but the are a marvel to listen
to. Give me Tannoy or give me Line Arrays.

I had MX100s for quit a while, compared to the Moab in a treated room, few would complain in a blind test, both work VERY well,
once you understand how they work. The Moab I used had low/high binding post. It literally was night and day between single post.
There were ZERO braces in a Moab cabinet. The long panels did resonate with the pro drivers. MX100, not a bit, much better
cabinet construction. The ability to turn down the bass section was the key with my sub/bass setup.

I use/used a bass columns/servo-subs DBA. Anything works in that setup if you can control the bass in you mains. I just cut the
wires to the bass in the single post Moabs I used. There is a LOT of room an a Moab cabinet. It needs a mid bass coupler and
HiFi sub drivers in a 4 way. Not pro drivers. The compound array is pretty friggin' nice. I'd add a ribbon for the HF tweeter though.

Better than most speakers for the money actually, if your listening with your ears not your eyes.

Regards

 

[Rick Sykora]

Yes, pretty much, although with the caveats that I think Tekton uses quite a few different tweeters, the TW29TXN-B is one of the better ones, 800~900 Hz might be the greater challenge as tweeter distortion can increase rapidly as you approach the Fs and at least one of these speakers I read about ( I think it was the Impact Monitor) has a crossover frequency of 772 Hz, although again allowing for the slope).

While broadly there are technical commonalities, would help to know when are talking about a $2K speaker vs a $30K speaker. For example, 772 Hz is one of the crossover points for the more expensive MOAB. For the Impact, there were no posted crossover points but only some educated guesses. I chose around 1300 Hz as the diyaudio sim suggests.

As for the OP’s question, while the tweeter array appears technically feasible, it does not offer any obvious superior benefit. The designer’s claims about mass and array bandwidth are illusory at best. For either speaker, neither array handles the claimed A-Note and most of it's harmonics. The directivity is unexceptional. If as the diyaudio thread suggests, there is a CBT quality to the array, would need measurements at different distances to confirm.

 

[cavedriver]

While broadly there are technical commonalities, would help to know when are talking about a $2K speaker vs a $30K speaker. For example, 772 Hz is one of the crossover points for the more expensive MOAB. For the Impact, there were no posted crossover points but only some educated guesses. I chose around 1300 Hz as the diyaudio sim suggests.

You are correct with the 1k number, my bad. It's not in the stereophile specs or measurements, but it's in the text that the Impact is at 1k:

"The seven tweeters are oriented in what I call a 'polycell array.' The 6.5" woofers handle frequencies below 1kHz, and the seven-tweeter polycell array handles frequencies above 1kHz."

 

[thewas]

772 Hz is one of the crossover points for the more expensive MOAB

I love meaningless and wrong pseudoprecision that shows that the guy who writes it doesn't really have experience in what he is doing.

 

[Doenerkunde]

What do you guys think about this model?

It employs waveguided Wavecor 30mm tweeters, that are regarded as some of the lowest playing dome tweeters on the market (FS in the low 400s).

Manufacturers Data: https://www.wavecor.com/html/tw030wa11_12.html

Independent measurements of the no ferrofluid 4Ohm version: https://hificompass.com/en/reviews/wavecor-tw030wa11-tweeter

 

[Rick Sykora]

I love meaningless and wrong pseudoprecision that shows that the guy who writes it doesn't really have experience in what he is doing.

ok, but not sure of the precise source (individual) as the stated frequency was posted in Stereophile’s review of the speaker....

 

[Rick Sykora]

You are correct with the 1k number, my bad. It's not in the stereophile specs or measurements, but it's in the text that the Impact is at 1k:

"The seven tweeters are oriented in what I call a 'polycell array.' The 6.5" woofers handle frequencies below 1kHz, and the seven-tweeter polycell array handles frequencies above 1kHz."

Had not seen this previously, is it a quote from the designer?

 

[Sokel]

Would tighter spacing of the tweeters improve performance?
If for example 70mm tweeters instead of 104mm (outer dimension) were used would that be better?

 

[Randolf]

What do you guys think about this model?


It employs waveguided Wavecor 30mm tweeters, that are regarded as some of the lowest playing dome tweeters on the market (FS in the low 400s).

Manufacturers Data: https://www.wavecor.com/html/tw030wa11_12.html

Independent measurements of the no ferrofluid 4Ohm version: https://hificompass.com/en/reviews/wavecor-tw030wa11-tweeter

That's the 2-12 PERFECT SET right? If it uses the Wavecor TW030WA12 (looks like it does) it seems to be one of a few dome tweeters which had been reviewed and recommend to be crossed over as low as 1 kHz. Sounds like a reasonable choice. Tekton description complaining about horn and waveguides

"Proprietary controlled directivity – acoustically superior proprietary polygon-oriented, triple-ring radiator high frequency array. This array disperses a precisely focused acoustical power pattern of that of a horn or waveguide without the audible ringing influence of horn flare walls constraining the soundwave for acoustically superior mid-range high frequency performance"

is of course somewhat strange when actually using waveguide tweeters.

However Tekton offers a 6000$ Berylium tweeter upgrade even for that one:

 

[thewas]

ok, but not sure of the precise source (individual) as the stated frequency was posted in Stereophile’s review of the speaker....

View attachment 364246

Obviously the source is Tekton itself as JA wouldn't write such nonsense.

 

[cavedriver]

Had not seen this previously, is it a quote from the designer?

Nah, it's from the Stereophile reviewer (the prose part, not JA). I assume he got it from Tekton because John doesn't call it out anywhere that I found in the measurements. It could well be inaccurate or even a swag. John doesn't measure the center tweeter separately from the array like a designer would want to and when he shows the woofer he shows it overlapped with the mids and tweeter so we can't see where the woofer falls off to guess the crossover point.

 

[Randolf]

That's the 2-12 PERFECT SET right? If it uses the Wavecor TW030WA12 (looks like it does) it seems to be one of a few dome tweeters which had been reviewed and recommend to be crossed over as low as 1 kHz. Sounds like a reasonable choice.

In case you are interested in DIY sets using the Wavecor TW030WA12 you can have a look https://www.lautsprechershop.de/intro/suche_kit_en.htm , just enter TW030WA12 in the "Search used speaker chassis:" and you will see all sorts of kits, e.g.

https://www.lautsprechershop.de/hifi/rhone_en.htm third order high-pass filter at 1000Hz
https://www.lautsprechershop.de/hifi/cursa_en.htm first order high-pass filter at 1650Hz

So it is somewhat questionable why one need an array of these tweeters at all to achieve a low crossover point.

 

[Randolf]

Nah, it's from the Stereophile reviewer (the prose part, not JA). I assume he got it from Tekton because John doesn't call it out anywhere that I found in the measurements. It could well be inaccurate or even a swag. John doesn't measure the center tweeter separately from the array like a designer would want to and when he shows the woofer he shows it overlapped with the mids and tweeter so we can't see where the woofer falls off to guess the crossover point.

Often you can guess the crossover point from the impedance curve. From the Stereophile impedance measurements of various Tektons my guess is

14+1 array: 772Hz (well don't take it too serious it might be 771 or 773 )
6+1 array: ~1000Hz
2+1 array: ~1200Hz

 

[cavedriver]

Would tighter spacing of the tweeters improve performance?
If for example 70mm tweeters instead of 104mm (outer dimension) were used would that be better?

I assume that the lousy off-axis measurements of the bigger Tektons in Stereophile are because the upper crossover point between the arrays and the single tweeters is causing significant lobing or uneveness in the sound field. To me, so far, this is the biggest failure of this design- by having multiple drivers that are operating too far apart for the frequencies they are reproducing there is significant vertical and horizontal unevenness. This is why I'd really like to see one of these larger Tekton's reviewed.

 

[Randolf]

I assume that the lousy off-axis measurements of the bigger Tektons in Stereophile are because the upper crossover point between the arrays and the single tweeters is causing significant lobing or uneveness in the sound field. To me, so far, this is the biggest failure of this design- by having multiple drivers that are operating too far apart for the frequencies they are reproducing there is significant vertical and horizontal unevenness. This is why I'd really like to see one of these larger Tekton's reviewed.

Yes I would also really like to see a Klippel NFS measurement of the 14+1 and 6+1 array, but I guess for very well known reasons nobody currently likes to measure any Tektons at all.

 

[Salt]

Would tighter spacing of the tweeters improve performance?
If for example 70mm tweeters instead of 104mm (outer dimension) were used would that be better?

As @OldHvyMec pointed out, the closer the drivers the stronger magnetic interferences might be, so a magnetic shielding could be an idea like here:
https://www.visaton.de/en/products/drivers/dome-tweeters/ke-25-sc-8-ohm

 

[617]

Does anyone have detailed directivity measurements of the so called coax array? I'd be curious how well Tekton got it to work. I find it intriguing that he made it asymmetrical.

 

[Rick Sykora]

Does anyone have detailed directivity measurements of the so called coax array? I'd be curious how well Tekton got it to work. I find it intriguing that he made it asymmetrical.

Can get an idea from the Stereophile measurements for the Impact monitor.

@ROOSKIE can you help?

 

[Randolf]

Does anyone have detailed directivity measurements of the so called coax array? I'd be curious how well Tekton got it to work. I find it intriguing that he made it asymmetrical.

I would not call these Tektons arrays "coaxial", obviously the 2+1 and 14+1 arrays are not even coaxial from a geometric perspective and even in the 6+1 array the top and bottom tweeters are used for a different frequency range the the other 4 ones on the left and right. So we can expect more evenly radiation on the horizontal than on the vertical axis, which is what we see in the 3 stereophile measurements:

2+1: https://www.stereophile.com/content/tekton-design-enzo-xl-loudspeaker-measurements
6+1: https://www.stereophile.com/content/tekton-design-impact-monitor-loudspeaker-measurements
14+1: https://www.stereophile.com/content/tekton-moab-be-loudspeaker-measurements

This has little in common with a real coaxial or fullrange driver.

 

[617]

I would not call these Tektons arrays "coaxial", obviously the 2+1 and 14+1 arrays are not even coaxial from a geometric perspective and even in the 6+1 array the top and bottom tweeters are used for a different frequency range the the other 4 ones on the left and right. So we can expect more evenly radiation on the horizontal than on the vertical axis, which is what we see in the 3 stereophile measurements:

2+1: https://www.stereophile.com/content/tekton-design-enzo-xl-loudspeaker-measurements
6+1: https://www.stereophile.com/content/tekton-design-impact-monitor-loudspeaker-measurements
14+1: https://www.stereophile.com/content/tekton-moab-be-loudspeaker-measurements

This has little in common with a real coaxial or fullrange driver.

I'd just like to see some actual directivity sonograms and not this retro stuff from Stereophile.

In theory a coaxial with different vertical and horizontal radiation could be useful, not to say this is the way to go about it. The quasi coax with the ribbon and midranges created by the german guy measure extremely well.