I am using mine with a Bach 5B and it certainly improves the slotting and tone

The booster improved my tone, my pitches, and the overall control of the horn in all registers

I purchased this product to help boost/center my tone

It allows me to play softly and maintain good tone and pitch easily, with or without a mute.

I pride myself on my good dark, symphonic tone, but wow, I really thought that I'd just try this and nothing would change

love it beatiful tone excellent control

It improves my tone, range, and dynamic contrast