Audax metal dome tweeters?

Curious if anyone has experience with or measurements of the Audax TW025A28 or TW025A20? The gold one sounds like it simply a gold plated titanium version of the regular titanium, but the response plots are quite different. And they look different measurement systems at different times, so I'm wondering if that is why they are so different?
I had a "titanium coated" 25mm Supronyl Audax dome tweeter in one of my older projects. Quite nice, but no titanium dome, even as it had "Ti" in its model number and looked silver gray. So not any "Ti" called Audax may be a real metal dome. It is quite complicated to decipher them, as there are so many Audax model names, made up from letters and numbers. Anyway, all Audax tweeter I tried did an excelent job, you won't find one that is really bad.
The face plate is removeable on most larger (1") Audax tweeters and the dome replaceable. Part of the construction. You can change face plates from round to rectangle.
Ferro fluid cooled and dry domes have very different plots. You should see it in the impedance.
  • Like
Reactions: 1 user
I made a kit back in the 80s with a titanium version of the HD100D25 in fabric - now TW025A0 - and its dome seems very similar to the TW025A20. It does not look like a metal dome but more like plastic material (it's quite soft) with a titanium treatment on the surface. The sound has a good balance, it is more vivid than the fabric dome but not harsh.
Neither of these tweeters are Al/Mg. They are titanium but one says gold plate. I wonder if that is actually TiN treatment?

Does anyone know if the faceplate can be removed?
No gold plated as the mfg. states.
And the TW025A28 is quite nice, but might benefit from a notch for the breakup, not far past 20k.
It's a rather aged design, the catenary dome profile helps push the breakup, up in frequency.

TIN coating on domes is a rather new thing, and these tweeters have been around for a long time.

yes the faceplate is removable, with the 4xM4 screws visible on the front
They do have a magnesium cone option ! Which is said to be the best of the metal dome from Audax. An oem version that is sourcable without effort by any diyer.

For the Ti they indeed chosen a "gold" color coating to prevent rusting, the other ref has a varnish on it in spite of the said high-end golded cone, last of the tweeter made by Audax.
Last edited:
Both the A20 and A28 are essentially the same tweeter and sound identical to my ears.

I haven't measured FR on both of them, but impedance is identical and they do appear to be the same based on what I'm hearing and seeing from diasassembly. I have swapped A20 domes into the A28 and vice versa. They are interchangeable. I listened to both versions at once in left and right positions using mono recordings. They sound exactly the same to me using this test, as close to a stereo pair you would expect.

The faceplates are the same as well aside from the single wire dome protector on the A20 and double wire on the A28, plus the gold plated screws. The gold plate on the A28 dome is done via vacuum sputtering.

Both these tweeters are to my ears some of the best Ti domes available. They sound like planars and ribbons up top, efficient, very detailed yet non fatiguing. The back chamber is a work of art as is the neo motor. I measure almost 2.0 T - very high flux for this size driver.

Both are by far my favorite one inch Ti domes at any price. I'll post some pics of the VC asys from both. I should have spare VCs from the A28 as well.
  • Like
Reactions: 1 user
I see Hificompass tested the gold dome. The reason I was looking at this tweeter was I wanted a reasonably priced, well behaved, metal dome tweeter that will work in a waveguide but with high sensitivity so it can be used where the SB26CDC cannot. These Audax looked to be candidates. I see Hificompass measured the gold dome and it doesn't look high sensitivity at all. Looks a lot like the SB actually. Which is at odds with one of the sites above, dibirama I think. So I don't know what to think.
Imo it's just a little too much expensive due to the newer designs everywhere with much more lower Fs. But if augerpro draw a smart WG for them, one certainly get rid of the high cut-offs needed (A28) >2500 hz. Maybe even more needed for the A20 (3000 hz ? See Kelinac audio).

Tha sb26CAC is said to be hard to beat but has low sensivity though augerpro WGed it.

I suspect if passive a good cap maters more to approach what on likes !

But I dunno. Profiguy seems to appreciate the gold one and has experience in relation to many different trebles in his journey.
Last edited:


  • waveguide.jpg
    77.8 KB · Views: 53
  • IMG_20200610_165246.jpg
    349.8 KB · Views: 53
  • IMG_20200610_190402.jpg
    311.2 KB · Views: 55
  • Like
Reactions: 3 users