Why a custom harmonica?

One thing right from the top: a warm and full sound can only be achieved by the harmonica player.

The harmonicas that Joel Andersson has carefully customized will help every player realize their potential and personal sound on the instrument. With handcrafted precision, Andersson brings the best out of every instrument. The optimized reed plates and combs on JA Custom Harmonicas aid beginners when learning playing techniques. For professional players, they are reliable partners enabling performers to concentrate completely on the musical elements of their performances.

Reeds are gapped slightly higher so you can hit them a bit harder without the reeds choking.
The basic reed work gives the harmonica a better response and more volume than a stock harmonica.