TB new line of Coax FR drivers

There's a suggested enclosure and crossover posted on the Tang Band website for the W6:

SUG2-25 - 6.5" 2 Way Coaxial Bookshelf Enclosure Suggestion - TB SPEAKER CO., LTD.

Looks like a Kef LS50. Interesting curved port tube....
The curved port is quite common to accomodate a longer tube than what would fit straight.

I find the XO to be a bit weird though... No lowpass for the woofer? The notch only affects the impedance as far as I can see. When I sim it with the factory curves i get this (still without baffle step):
SUG2-25 - W6-2313.png

The page says that the XO-point is 3 kHz, but that looks a lot higher than that...

/Anton
 
Still not sure why most of these co-axials are built at this size. Having such a low crossover for the tweeter makes little sense in a coaxial configuration.

Sure these are great for some near field monitors.
But personally, i feel an optimal application for coaxial would be upper mid + tweeter in a 4-way. A 3.5" or 4" mid-range covering from 700-5kHz coaxial with a small tweeter from 5kHz and above.

1. C2C is not a problem even at that high frequency XO
2. Crucial frequency range is covered in a single driver without XO
3. Low excursion needed from the mid-range driver means that the surround can be optimally designed for low diffraction.
4. Cone profile can be designed for optimal wave-guide loading for the tweeter
5. Low excursion also means this wave-guide is stable wrt to the tweeter and avoids distortions coaxials may be more prone to.

Granted this may be a limited application.
 
Last edited:
Hi Onni,
I used the data from you. Both LspCAD and VituixCAD give other results than your chart. The phases are not aligned to each other. I do not know where the bug is.


I started with first order filters, a Zobel and an L-pad and got this:
View attachment 688750

That's not so bad, right? I haven't added baffle diffraction yet though.

/Anton
 

Attachments

  • TB 6,5 xover.jpg
    TB 6,5 xover.jpg
    155.4 KB · Views: 2,039
I think we might all need a new hobby. :eek:

These coaxial drivers are getting so good, that there really isn't much more to do!

This is effectively a three-way with a small footprint.

The $500 Elac Uni-Fi UB5 designed by budget specialist Andrew Jones of Pioneer fame: Uni-Fi UB5 – Elac

One of my favourite Tech reviewers, Patrick Norton gushes greatly over it in an interview with Andrew: YouTube

Not many people know this, but my avatar is, in fact, Robert Heron, who had a great partnership with Patrick on various tech websites. Get your geek on! :D

I heard one of the ELACs back to back with Kefs LS50 and I think it's a little bit better. Really great speaker, especially at that price.
 
I got this, using both frd and zma files I made from the TB graph.

You can't place an L-pad out front like that. A single series resistor is okay, but a full L-pad is not bandwidth limited to the tweeter via the HP, and those resistors will get hot shedding that heat from 20-20k.

I highly advise against this.

Later,
Wolf
 
Pandinus, Omi exacted the phase in XSim after importing the frd-zma files.
What's not known is the delay between the two sections.
Yes, exactly. Sorry for not being clear. I'm not sure if I can save the curves in Xsim.

I think that the delay should be close to 0 with this kind of setup (tweeter close to acoustic center of woofer). I'll make measurements when it arrives.

/Anton
 
You can't place an L-pad out front like that. A single series resistor is okay, but a full L-pad is not bandwidth limited to the tweeter via the HP, and those resistors will get hot shedding that heat from 20-20k.

I highly advise against this.

Later,
Wolf

Oops! It was late and my eyes were crossing!
Just shows that because you can do a thing, it is not always a good thing to do so!

These sims allow us so many combinations, but there's nothing better than hands on experience!

I re-did the W6 and also did the W8. Comments welcomed.
 

Attachments

  • Screen Shot 2018-06-27 at 12.21.19 PM.png
    Screen Shot 2018-06-27 at 12.21.19 PM.png
    179 KB · Views: 1,386
  • Screen Shot 2018-06-27 at 12.22.10 PM.png
    Screen Shot 2018-06-27 at 12.22.10 PM.png
    180.2 KB · Views: 1,373
Oops! It was late and my eyes were crossing!
Just shows that because you can do a thing, it is not always a good thing to do so!

These sims allow us so many combinations, but there's nothing better than hands on experience!

I re-did the W6 and also did the W8. Comments welcomed.
That looks good! Let's see how the tweeter feels about the low XO point.

Are they wired with same polarity? I had woofer inverted.

/Anton
 
Woofers in both cases are inverted.

I crossed that low to take away the peak from the woofers at 2Khz which would interfere with the tweeter output.

TB says their tweeter can reach 800Hz, and I am about -15dB at 800Hz, and dropping fast.
I thought they meant that it's flat to 800, which is due to fs around that point and high Qt (around 0.8?).

The phase in your sims is very smooth, how did you extract phase from measurements?

/Anton