I've just owned and played Beuscher 400 (big bell) and they produced a big free blowing sound. The sound was big all over, from the top to the bottom. I think Beuscher wanted to get new customers and introduced the "400" in the 40's. Before the WWII Selmer introduced the Selmer BA model and that didn't leave any rest to other manufactors. After the war King introduced the Super 20, Conn the Connqueror, Martin "The Martin" and Beuscher the "400".
Lynn Hope and Lee Allen (Pete Thomas knows more about this) played Beuscher 400. Johnny Hodges (Duke Ellington) played Beuscher and Besuscher were also popular among classical saxophonists. The tone was/is 'Sweet' and 'Warm'. The Beuscher with the big bell were supposed to help the company into the new time.
The music changed after WWII and the big bands wanted more volume and louder sound. The new music also brought new saxplayers and new styles. The big bands became smaller (combos). We can trace the first R&B och Rock 'N' Roll tunes to Tiny Grimes (Red Prysock, Benny Golson, John Hardee), Jack McVea, Joe Liggins ("Little" Willie Jackson, James Jackson), Paul Williams (Miller, Pope and later Noble "Thin Man" Watts) among others.
I know that Cannonball and now also Bauhaus has a big bell saxmodel. I don't know if new big bell saxes produce a bigger sound. You can also use a clip-on-mic and amplification to get a bigger sound.
Sorry I went out of topic.
Thomas