You can see distortion measurements or the 70x20xr in the Ascend Horizon review here (the directivity plots of this horizontal center channel won’t likely correlate much with the towers, but it uses the exact same driver components so I expect the distortion measurements should be more or less the same):I wonder what the maximum SPL without compression the Sierra Towers with the larger 70-20xr ribbon tweeter could do when properly crossed over to subs? It's ~90dB sensitivity and the larger RAAL supposedly has much higher power handling than the 64-10 in the bookshelves.
Better, but still isn't going to compare with other high end tweeters at extremely high SPL.
Example of a very high performance tweeter from the Revel F328Be:
The dynamics difference between these is definitely audible when you listen loudly, or music with loud peaks (e.g. orchestral). However not everyone needs or even wants the ability to push 100-120db peaks effortlessly, as it at least risks annoying non-audiophiles during listening sessions
I didn’t think I wanted to ever push speakers to 100-120db until I heard speakers that can do it effortlessly. Of course you don’t listen at this level continuously, but experience dynamic peaks that occasionally reach high SPLs in movies or high dynamic range music.
Extreme SPL capability is IMO very important for “endgame” speakers. But not necessarily the most important thing when a compromise must be chosen. So it is IMO a totally fair compromise for Ascend to be making. I doubt the majority of people actually ever want their speakers in a domestic situation to exceed 96-100db often.
For Ascend to match the dynamics ability of other speakers like the F328Be would probably require them to move away from a RAAL tweeter, thus compromising the wide sound (to some extent) that they are very much loved for.
The Salon2’s show that it is possible to achieve without almost any compromise, but that it is very expensive and difficult to achieve. However in theory, I wouldn’t put it past Ascend to develop some kind of Revel-killer product now that they have an NFS