Arguments against "super tweeters"

[celef]

And why I've historically used/suggested a compression horn driver with a short WG or just a round over for ones with an internal conical horn to get a smooth transition

can you please give an example of such a mid driver?

 

[GM]

Thought this was about [super] tweeters, with Altec/GPA, TAD or similar 1" the historical choices.

For mids [~250- 2 kHz], historically would have to create a BP4 alignment using a very efficient point source [horn] driver with of course a larger, but truncated, horn.

GM

 

[diyiggy]

They were all the rage a few decades ago, and a few still sold, but I was wondering looking at the need to move to a 1 1/8 tweeter to get the crossover low enough for a 6 inch mid/bass, but top end issues and excessive stored energy make it a less than an optimal option. What are the drawbacks from the larger tweeter, and then slap something with a great top end, even a little XT-25G on it for 10K up? First order crossover even.

I would rather a really great midrange that could get up to 4K where you could use one of several decent 3/4 tweeters, but they seem to be in short supply or their efficiency is so low, you would have to bi-amp.

More or less in the same situation with a mid that is 3" the SS 10F, which could be crossed up to 4khZ without problem and 10k flat at 30° off axis.

My beginner opinion -but 35 years of hifi listening experience though- as I am in the tweeter choice as well :

-a 3/4 dome will have in the best a 900 Hz Fs and despite the 4K XO is 2 octaves above that it is certainly too much short for a 6dB But.
- the center to center is great with the 3/4 for such 4K hZ XO like the Peereless OW19 for instance (hificompass measurement) or a little worse SB26RDNC.
-Alas this is not too much the highs that make a great tweeter but its behavior in the low end : frequency shape and slope there, distortion below the Cut-off as well right in the high midrange where the ears are still sensible !
- Alas at 10K Hz the C to C is almost impossible, forget also a wave length of C to C with 3,4 cm. (with the OW19 you can go as close as 1/2 WL c to c 🙂 ).

Imho what you are hearing with a6 dB XO first order at 10 K Hz is not the tweeter too much but the overlapping between it and the mid till 2.5 to 3 x octave below the XO.

Of course I can be wrong, YMMV, just my two cents as I'm in the same thinkings and choice situation.

For myself, the question is more the trade off between a 1" with a 3k Hz XO 12 dB or higher VS a one Wawe Length of CtoC with a 1" tweeter that has not a spl bump in its low end upper that the crossover frequency, a much better low end distortion.

There is also the time issue due to the high XO and phase issue. Some studies show that you don't care about phase flatness in the last two octaves. But without electronic delay I'm not sure an asymetric XO can solve the time alignment issue due to the bigger horizontal center to center issue whatever first slope involved.

In your shoes and only if I had active setup to figure out the time delay, with your wish of 10 K hz XO first order, I will go for a 1" or a 1.1" Peereless DA25XT or a DA32TX or the classic DX25 bullet version or of course the ScanSpeak reprise of the classic HDS tweeter.

FWIW, I'm just a noob 😀

 

[cracked case]

How about pointing the super tweeter backwards and wiring out of phase? And if so would it need to be directional ( horn ) or not ( dome ). Would backwards be better than upwards or away from the other speaker?

 

[diyiggy]

there were some martin logan ESL with such a solution iirc : ESL + a dome in the half last octave ! Don't remember if it was firring towards the back or the celling...😕


I'm not aware of anyone who have used a back dome with something else than a front tweeter as well. But indeed, the idea of a 3 or 2.5" full range at the front and a dome for ambiance at the back... why not a little toeing in with the 90° back angle for the tweeters as a horn ?


Sonus Faber, Triangle, many brands use a back tweeter in plus of the front one.

 

[AllenB]

The factory data should show you how high they go, this should show you what they can do with their mass... It may or may not show the effect of the breakup modes. This could be one of the reasons to cross it, or to choose another driver.

Dispersion also changes, I don't think that narrowing is necessarily a bad thing as it is a matter of taste, and some prefer their highs to be free of earlier reflections in the room by keeping them narrow.

 

[system7]

Try Last Christmas. 😉 A terrible film in many ways, partly by intent, but the actors rise above it. Emilia in particular. Looks apart, in all seriousness, I've a lot of time for her -performing in blistering heat just after brain surgery and a titanium plate being inserted into her skull? If that doesn't deserve respect, I don't know what does. And it was interesting to watch her develop as an actress over the past few years -quirky, intense, much more subtle than she sometimes gets credit for. It's always been there, across the eyes and upper face. And significantly, nobody seems to have a bad word to say about her -she just seems a thoroughly pleasent person.

Ahem. Sorry for the OT there. Indulge us, it's Christmas (well, nearly), and I come from an acting family so I can't always help myself. 😉

Life is stranger then fiction. "Last Christmas" has finally made it to Number One.

Wham! - Last Christmas (Official Video) - YouTube