Interesting because I did not hear that. Toggling back forth between the two Mauriats, I don't hear any notable change in the tonality , to me they sound like the same horn being played......the only difference noted in the vid, to mine ears, was the player's impression, verbally stated, that there was a diff....
Might hear it if in the room listening live.
Only repeating what I have read on -
Brands and Horns | JazzBariSax.com
"Some swear by low A horns and some swear against them. The way I see it, everyone who uses a Low A essentially just wants that extra note. I have not come across too many players that play a Low A because of the way it sounds. I don’t think the Low Bb players dislike having an extra note, they are simply not willing to sacrifice anything for it. The Low A definitely weakens the power of the low end of the horn. From a business perspective one could argue that you need a low A for when Broadway shows, recording sessions (jingles) or big band charts . That being said, I do have a Low A baritone in the closet should I ever need it.
The Low A horn is not a bad idea in theory.
However, they don’t seem well thought out. When designing a Low A horn the bell is generally just extended and another tone hole is drilled. If you look at any saxophone the opening at the neck is the smallest in diameter and the bell is the largest. Small to big. When they add a Low A they stop expanding the size of the tube so that the diameter at the Bb tone hole is the same as that at the Low A tone hole. Not that I blame them, to make a bell large enough to be in correct proportion it would have to be huge. But that doesn’t nullify the fact that the bell on Low A horns is just not big enough to account for all of the notes. To build a Low A horn you must design it
from the neck down! Modern Low A baritones don’t resemble any of the other saxophones, just as straight soprano’s do not. the shape of the horn, bore dimensions, and bell size all vastly affect the sound of the entire instrument.
Low end aside, the extra hunk of metal on the end of the bell affects the resonance, timbre, and overall sound of the rest of the horn. Everyone claims you need a Low A baritone to play in a big band. This seems ironic to me, as it is much easier to punch the low end of the horn and support a section without the extra tubing!"
Now add the extra mass of the air column that needs to be moved because of the longer bell.
I must assume the intonation must be better on the newer Low A s?