Comparing Ribbon Tweeters - Golden Ear vs. Ascend Sierra

The Beyma tpl-150h is a very good sounding amt driver and would make a excellent replacement for a certain 7 tweeter array that’s popular.

I do like it better crossed a little higher though,2k to 2.5k with a really nicely built single order 6db crossover.

Ribbon and amt tweeters can be really good or really bad depending on the rest of the speaker implementation.

Good luck in your search,
Kenny.

True ribbons and AMTs both have strengths and weaknesses.  

AMTs are easier to scale up in size and can cross over lower than practically sized true ribbons.  They can also be very good at handling rather extreme amounts of power.  On the downside they don't have as wide a horizontal or narrow a vertical dispersion as true ribbons.

True ribbons, specifically something like the RAAL used in many nice designs, are reportedly better at reproducing subtle variations in the signal than AMTs, and they have a great wide horizontal dispersion with a very narrow vertical dispersion.  The downside of that great horizontal dispersion, however, is that it can be a mismatch with a lot of cone woofers at the crossover point - the higher a woofer plays the more it starts to 'beam' and narrow its dispersion, so a narrow dispersion from the woofer combined with a wide dispersion from the ribbon can make for a mismatch that leads to ragged off-axis performance.  

Philharmonic Audio makes a great speaker in the BMR Philharmonitor which addresses the dispersion issue by adding a BMR midrange driver that has a very wide dispersion into the mix - the woofer doesn't have to play as high so it doesn't beam, the BMR midrange maintains wide dispersion through the crossover frequencies, and the RAAL ribbon can do it's thing up top.  They're also not much more than the Ascend Sierras w/RAAL.  Plus, the designer Dennis Murphy is known to be a crossover and speaker design wizard and has collaborated on many of the Salk sound designs.

http://philharmonicaudio.com/BMR%20Philharmonitor.html

The dispersion of any radiating surface is related to the frequency and dimensions of the radiator. AMT’s are typically wider than ribbons, but they come in a variety of lengths. Some shorter than ribbons, some longer. 

Also, I don’t think limited dispersion is a negative at all, unless you happen to have a perfectly tuned room. :)

And yeah, the better one's have amazing dynamic range with little distortion or compression. 

True, but as most AMTs are more square compared to most ribbons being tall and skinny most AMTs are going to have more limited horizontal dispersion than most ribbons, there are, of course, always exceptions.  

Also true that the room will certainly have an effect, and in certain rooms high directivity is a bonus, but in others a wider horizontal dispersion can add to the experience, plus offer a wider sweet spot.  

Over on AVS there was a controlled blind test between the JBL M2 and the Revel Ultima Salon 2.  Going in a lot of people were thinking that the M2, with its controlled directivity, was going to win the day, but the Ultima Salon 2 ended up taking the honors.  Now, that's not a ribbon or AMT speaker, but domes still have wider dispersion than compression drivers with controlled directivity waveguides. 

http://www.avsforum.com/forum/89-speakers/2907816-speaker-shootout-two-most-accurate-well-reviewed-s...

Do not underestimate the waveguide on the revels. You get very good and controlled off axis response.

Would I trade my current AMT speakers for a Revel? Never. :)

Best,

E