for string instruments, there are optimal ranges for string-length, tension and thickness that vary with its frequency. Which is why for example a violin has sh

for string instruments, there are optimal ranges for string-length, tension and thickness that vary with its frequency. Which is why for example a violin has shorter strings than a cello or a contra bass. Similarly, acoustic (non-electric) bass guitars don't work so well, etc. To my understanding in a piano, the lower strings are "too short", this includes grand pianos at a concert hall for example. There is a compromise in the construction. The Alexander Piano has an adequate length of strings, so in principle it has better sounds in the lower frequency ranges.