In my experiance, the response ("play better") of a mouthpiece depends mostly on the quality of the facing curve. Say 70%. Next, the parts nearest the tip rail are important. The baffle, window width, tip rail, tip corners. Say 20%. Then I would tag the importance of the chamber design as 10%.
Now for impact on sound, not response, the chamber and baffle design are very important. Like 90%.
But I would not round out a rectangular chamber. It is part of the character of the mouthpiece. Most of the effect from rounding it out will be that you are making it larger.
Now for impact on sound, not response, the chamber and baffle design are very important. Like 90%.
But I would not round out a rectangular chamber. It is part of the character of the mouthpiece. Most of the effect from rounding it out will be that you are making it larger.