Actually, all those instruments were already extended beyond their natural range (sometimes by more than an octave), and we went as far as possible while keeping a clean and homogeneous sound. The problem with those metal plates instruments (celesta, toy piano, glockenspiel, but also tubular bells...) is that they have such a strong inharmonicity that below a certain range, the pitch becomes so uncertain that you cannot tell anymore which note you are playing.

OK, that makes sense. I guess I can create a split with the vibraphone or another instrument. Thanks

Because for those instruments extending them too far out probably didn't sound as good as the range that was decided upon for the final product.

Maybe it wouldn't sound great through a whole 88 note range, but the consumer should have the option of extending the range of the instrument.

I would be more inclined to buy the Celeste and Toy Pianos if I could have more notes to play on. I suppose I could create a split and put a vibraphone below ...